what We Know: Underlying Processes

The balance between energy absorbed by the earth and energy reflected back into space is fundamental in determining how warm or cool the planet becomes. The proportion of radiation reflected away by a surface is called its albedo. Albedo can range between 0 (no reflectance) and 1 (complete reflectance—like a mirror). The earth’s average albedo is .31, which means that, overall, the planet reflects about 31% of incoming solar radiation back into space. But forests and deserts, oceans, clouds, snow, and ice all have different albedos—and changes in these types of ground cover can therefore affect how much solar radiation the earth receives. For example, the albedos of forests lie in the range 0.07–0.15, while deserts have an albedo of around 0.3.

This satellite image shows Antarctica’s Scott Coastline on January 4, 2002. The large, coke-bottle-shaped iceberg in the lower right broke off the Ross Ice Shelf in December 2001. (See “The Collapse of the Larsen B Ice Shelf” on this site for more information.)

The Dry Valleys are one of the few areas of Antarctica not covered by ice. Unlike much of the rest of the earth, the Dry Valleys have cooled over the last 100 years. (See “The Collapse of the Larsen B Ice Shelf” on this site for more information on the implications of this cooling trend.) The albedo of the earth’s surface varies from about 0.1 for the oceans to 0.6–0.9 for ice and clouds, which means that clouds, snow, and ice are good radiation reflectors while liquid water is not. (This is because clouds, snow, and ice have multiple layers that reflect radiation, whereas a body of water reflects only from its surface. A calm ocean is a poor reflector, but when it foams up in the surfline, producing many reflecting surfaces, it becomes white— reflecting most of the light hitting it.) In fact, snow and ice have the highest albedos of any parts of the earth’s surface: Some parts of the Antarctic reflect up to 90% of incoming solar radiation.

Continued global warming will have one obvious effect on the world’s polar ice, sea ice, glaciers, and permanent snow cover: Warmer temperatures will melt some of this frozen water. Melting of land-based ice sheets and glaciers could contribute to sea-level changes. (Melting sea ice would not contribute to rising sea levels: When ice floating in water melts, the level of the water doesn’t change. You can prove this to yourself by watching the ice melt in a glass of water.) (See “Global Glacier Volume Change” on this site for more on melting glacier.)

These photographs, taken in 1928 and 2000, show how South Cascade Glacier in the Washington Cascade Mountains has retreated over time.

Evidences and Uncertainties

Melting ice could change ocean temperatures. This, in turn, could change the course and speed of ocean currents, significantly change the habitats of sea organisms, and affect rainfall by altering the rate of evaporation of seawater.

Increases in sea levels and temperatures are not the only possible outcomes. When ice and snow melt, they generally expose a much darker underlying surface. Dark surfaces absorb more heat (have a lower albedo) than light surfaces. This suggests the possibility that a small amount of melting could lead to a warmer surface, which could melt more ice, warming the surface still further—initiating the positive feedback loop of a “runaway” warming trend. There is some evidence of such an albedo-reducing effect in the Cretaceous Period (120–65 million years ago): Fossil and other evidence suggests that there was little or no snow and ice cover during this time, and global temperatures then were at least 8° to 10°C higher than they are now. (See “Northern Hemisphere Snow and Ice Chart” and “South Pole/Ice Concentration” on this site to see the extent of current snow and ice cover.)

The cryosphere also provides a way to study past climatic conditions. If snow falls in a region of the earth where melting rarely occurs, it leaves a layered record as it deposits contemporary molecules and aerosols. As each layer is pushed deeper and deeper under increasing pressure, the snow turns to ice, capturing small bubbles of air. By examining ice cores taken from these areas, we can determine associations between past temperature and carbon dioxide levels. But one of the biggest problems in any ice core study is determining the age-depth relationship. Many different approaches have been used, and it’s now clear that fairly accurate time scales can be developed for at least the last 10,000 years. (See “Climate records from the Vostok Ice Core Covering the Last 420,000 years” on this site to learn more about the Antartica's Vostok ice core.)

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what We Know: Underlying Processes.

The earth receives a tremendous amount of energy from the sun. The land, sea, and air absorb some of this energy and reflect some of it back into space. The overall description of this process is called the earth’s energy budget. (See “Global Reflected Shortwave Solar Radiation” and “Global Outgoing Longwave Heat Radiation” on this site to learn more.)
The “greenhouse effect” is one aspect of this energy budget. Just as the glass walls of a greenhouse keep the interior temperature higher than that outside, the earth’s atmosphere traps some of the energy radiated from the earth near the planets surface. The presence of “greenhouse gases” (like water vapor and carbon dioxide), keeps the planet’s average temperature at a hospitable 15°C. (With no greenhouse effect, the earth’s average temperature would stabilize at about -18°C). Not all components of the atmosphere are greenhouse gases, however; in fact, oxygen and nitrogen, which together make up more than 95% of our atmosphere, are not greenhouse gases.

This diagram shows the processes that make up the planet’s energy budget. The earth’s surface absorbs shortwave radiation (red arrows) and re-radiates longwave infrared radiation (blue arrow). The numbers are percentages: For example, 30% of the solar radiation shining on the earth is reflected away.

The greenhouse effect is not in dispute—but it lies at the heart of the study of global climate change.


There’s no doubt that increases in the atmospheric concentration of carbon dioxide and other greenhouse gases strengthens the greenhouse effect and contributes to global warming.
What remains uncertain are the precise effects of a strengthened greenhouse effect on global temperatures. Because there is still much to be learned about how the world’s climate will react to increased greenhouse gas concentrations, the range of possible climate futures projected by the IPCC is an indication of uncertainty about how much the world will warm over the coming century—not of whether that warming is happening.


Aerosols are another key component of the earth’s atmosphere. These are suspended liquid and solid particles, including things like soot from fires and volcanic eruptions, sea salt, bacteria, and viruses. Aerosols affect the earth’s energy budget by scattering and absorbing radiation:


Overall, aerosols likely exert a cooling effect, because many of these particles tend to prevent radiation from reaching the planet’s surface (although due to their size and shape, some aerosols may help trap heat near the ground).

This satellite image shows a dust plume from the Sahara Desert blowing across the Atlantic Ocean. The green to red colors in the dust plume image represent increasing densities of tiny airborne particles known as aerosols.

Evidences and Uncertainties

Measurements from a variety of sources have suggested that the earth’s average atmospheric temperature has risen over the last several hundred years—but by how much? Taking the average temperature of the earth’s atmosphere is a very difficult measurement problem. First, measurements must be taken in a large and diverse enough range of locations to ensure that their average is truly a measure of global temperature and is not biased toward one region or another. Second, those locations must be chosen so that individual measurements are not thrown off by sources of unusually high or low temperatures, such as cities (which tend to be “heat islands” warmer than the surrounding landscape). Third, no measuring device is perfect—all measurements include some amount of error, or “noise.” Understanding the kinds of errors associated with different measurement techniques is a key element in evaluating the accuracy of a given temperature value. In addition, the study of climate requires measurements over very long time periods, so sources of paleoclimate data (data on climate from the distant past) are key to understanding climate change. (See “Global Stratospheric and Tropospheric Temperature Anomalies (1979–2001)” on this site to learn more about the problems of measurement.)

How much will global atmospheric temperatures change over the next century? Two kinds of problems make this an exceptionally difficult question to answer. (See “Sample Forecasts of Future Temperature Change” on this site for some possible answers.) First, the enormous complexity of the earth’s dynamic climate system—including the interacting air masses, winds and, ocean currents, and patterns of evaporation and precipitation—makes long-term climate prediction extremely problematic. Estimates drawn from reports by the Intergovernmental Panel on Climate Change (IPCC) project increases in average global temperatures ranging from 1.4 degrees to 5.8 degrees C by the year 2100. These numbers may seem small, but because average global temperatures are actually remarkably stable over long periods, this range actually represents a very significant rise in the earth’s temperature over a very short time.

A second problem complicating the picture is the unpredictability of human behavior. At what rate will the human population—and its production of carbon dioxide—grow? As formerly undeveloped countries expand their industry, often using cheaper (and more polluting) fossil-fuel technology, their contributions to greenhouse gases will rise and add to the problem—but by how much? To what extent will new, cleaner technologies (such as cars powered by hydrogen fuel cells) be developed and adopted by countries around the world? These kinds of uncertainties make the tough problem of predicting climate change all the more difficult. Even moderate increases in atmospheric temperatures could alter precipitation levels, making some areas wetter and others drier, and affecting agriculture worldwide. Warmer temperatures could increase the frequency and strength of storm systems, leading to more powerful and destructive hurricanes and subsequent flooding. Small shifts in the earth’s temperature could result in more powerful and destructive hurricanes. This satellite image shows Hurricane Isaac on the afternoon of September 29, 2000.

Slight changes in temperature may lead to higher ozone levels near the earth’s surface. This could significantly increase smog problems in large cities—bad for all of us, but especially serious for many elderly, ill, or otherwise physically vulnerable citizens.

Small increases in atmospheric temperatures could also change the way clouds form and dissipate. Warmer temperatures near the ground could cause lower clouds to evaporate, letting heat rise farther into the atmosphere.

As this heated air rises and cools, higher clouds form. But lower clouds usually reflect sunlight back into space while higher clouds tend to absorb more heat. More high clouds mean more heat trapped near the earth’s surface—so small increases in temperature could set off a cycle in which the atmosphere holds more and more heat over time.

(This is an example of a positive feedback loop—a system in which small changes in one direction may set the stage for later, larger changes in the same direction. But we don’t yet know whether positive feedback loops like this will dominate future climate, or whether other factors will prevent patterns like this from unfolding. )

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what do we know about global climate change?

We know that the earth has become warmer over the last century. The Intergovernmental Panel on Climate Change (IPCC), a group established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), reports that the average surface temperature of the earth has increased during the twentieth century by about 0.6° ± 0.2°C. (The ± 0.2°C means that the increase might be as small as 0.4°C or as great as 0.8°C.) This may seem like a small shift, but although regional and short-term temperatures do fluctuate over a wide range, global temperatures are generally quite stable. In fact, the difference between today’s average global temperature and the average global temperature during the last Ice Age is only about 5 degrees C. Indeed, it’s warmer today around the world than at any time during the past 1000 years, and the warmest years of the previous century have occurred within the past decade.



We also know that human activities—primarily the burning of fossil fuels—have increased the greenhouse gas content of the earth’s atmosphere significantly over the same period. Carbon dioxide is one of the most important greenhouse gases, which trap heat near the planet’s surface.

Red, orange, and brown coloring indicate areas where temperatures measured in 2000 are warmer than the average temperature from 1951 to 1980. The scale represents degrees in Celsius. Negative numbers represent cooling, and positive numbers depict warming.

The vast majority of climate researchers agree with these overall findings. The scientific disagreements that do still exist primarily concern detailed aspects of the processes that make up these largely accepted general themes.
You can think of this web site as a window into the world of scientific research. In this primer, you’ll find a general discussion of the physical processes underlying the earth’s climate, an outline of the kinds of data that may shed light on how the climate is changing—and the role of human activity in these changes —and a description of some of the questions and uncertainties that researchers continue to explore. This primer is organized into four interconnected sections: the Atmosphere; the Hydrosphere (the earth’s oceans and water); the Cryosphere (the areas of the planet covered by snow and ice); and the Biosphere (the living organisms inhabiting all these domains).

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Nepalese ministers meet in mountains.

From admin : To protect the planet green. with the development of site.cung comment and give your opinions. thanks very much.

Article published on the 2009-12-04 Latest update 2009-12-04 13:09 TU

(Photo: Reuters)

Nepalese Prime Minister Madhav Kumar Nepal and 22 other government ministers held a high-attitude meeting on the Kalapattar plateau on Friday to highlight the affects of global warming. Scientists say the Himalayan glaciers are melting, threatening mountain communities.

Members of the Nepalese government arrived by helicopter, equipped with oxygen, for a meeting at the world’s highest mountain range, in the shadow of Mount Everest, 5,262 metres above sea level.
Environment Minister Thakur Prasad Sharma denied that the meeting was a publicity stunt ahead of the Copenhagen meeting, and instead he drew attention to the melting of the glaciers.
Kumar told the Nepalese media that climate change was affecting people in the region and their, “socio-economic development”.
Scientists believe that thawing of the ice is creating glacial lakes that threaten mountain communities if they burst and flood downstream.
The disappearance of the Himalayan glaciers would also bring drought to large regions of Asia, where around 1.3 billion people depend on rivers stemming from the mountain region.
According to a study by the Asian Development Bank, climate change will, “cause faster melt and retreat among Nepal’s 3,252 glaciers”, “affect agricultural production and yield”, and increase the, “risk of malaria and encephalitis”.
Officials were expected to spend around 20 minutes at the meeting place and take part in the traditional Sherpa prayer ceremony, before approving the speech to be delivered by Kumar at Copenhagen.

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South and Central America

Arctica Travel Guide

Penguin on iceberg in Antarctica © Judith Duk

Antarctica can lay claim to several prizes in the continent stakes: it is the coldest, windiest and driest continent on earth, and with an average altitude of 7,382ft (2,250m), it is also the highest. The extreme frigidity and ferocious winds, as well as its isolation at the bottom of the world, combine to make Antarctica one of the most inhospitable places on the planet, neither inhabited by a native population nor presided over by an indigenous government.


Yet growing numbers of people are compelled to travel to this vast continent, double the size of Australia; a land of pristine whiteness, where its creatures have figured out remarkable ways to survive a life in the freezer. The landscape is as harsh as it is magical. Icebergs of indescribable beauty are carved and polished into fantastic shapes and sizes by the elements, patterns of blue ice form irregular etchings on the face of floating ice chunks, and the roar of calving glaciers echoes between sheer-sided channel walls. Roughly scoured peaks of rock and ice are reflected in the serene waters of protected bays that are frequented by basking seals and inquisitive whales. The coastal shores and sub-Antarctic islands are home to hundreds of squawking and honking penguin rookeries and seal colonies as well as nesting seabirds; the incessant commotion and comic antics of half a million tuxedoed forms is one of the most characteristic and endearing features of a trip to the Antarctic Peninsula.


The Peninsula is the northernmost finger that points to South America, and together with the islands of the Sub-Antarctic, is the most visited region and the best place to view wildlife in Antarctica. Most visits are on organised ship-based expeditions that aim to showcase the scenic highlights of the region as well as to educate visitors about the wildlife, historical sites and active research bases.


Antarctica is not an easy place to get to, nor is it a cheap holiday destination; part and parcel of this quest for adventure will more than likely involve a rough sea crossing, as well as an itinerary at the mercy of changing weather and ice conditions. However, those that choose to journey to the 'end of the world' can be sure of experiencing a voyage incomparable to any other.

Overview Argentina

A pony's reflection in the water in Argentina © fainmen

Argentina is a country of immense beauty and proportions. Its geographic diversity spans the most breathtaking terrain from Antarctica, through the wild, glacier-filled mountains of Patagonia and massive open plains of La Pampas to the deserts and tropical jungles in the north.


The country can be enjoyed for its natural wonders alone, but no visit here could be called complete without stepping into its soul, its capital city. The elegant Buenos Aires is home to 40 percent of the population, and is a buzzing metropolis with a rich, passionate and tortured history that is integral to its character. It is Europe and South America contained in one geographical location, with elements of the unknown around each corner. It is familiar and strange at the same time, but at its very core, wonderfully welcoming.


Along the elegant avenues of the fashionable districts, sophisticated diners observe passers-by while they sip strong coffee or enjoy smooth cervezas. There is a constant smell of meat grilling from every corner and sidewalk that reveals the Argentine passion for 'asado'. Neither glamour nor passion is in short supply in this cosmopolitan hub where Porteños are equally versed in football, politics and fashion.


There are disparities between the rich and poor, with many people living in near slum conditions in the outskirts of Buenos Aires. Since 1992 the economy has teetered near collapse due to corruption and government mismanagement, prompting regular and sometimes violent demonstrations. However it is business-as-usual as far as tourism is concerned; in fact, the resultant devaluation of the peso has made the country much more affordable for travellers.

Belize

Blue Hole

About the same size as Wales, Belize rests on the Caribbean coast between Mexico and Guatemala: an exotic, English-speaking, adventurer's paradise, just a couple of hours away from three major United States cities. Almost half the country has been preserved as nature parks and reserves, including tropical forests teeming with wildlife and hiding mysterious Mayan ruins, and 174 miles (280km) of coastline featuring the longest barrier reef in the Western Hemisphere.


The reef and the country's numerous offshore cayes, or atolls, have made this one of the world's most desirable destinations for scuba divers and marine researchers. They come to explore unique features like the famous 'Blue Hole', a collapsed submerged cave 1,000 feet (305m) in diameter and 412 feet (126m) deep.


Archaeologically Belize is fascinating too, having been the site of mighty Mayan cities from around 1,000 BC until the inexplicable disintegration of that great civilisation around 900 AD. There are believed to be thousands of Mayan ruins in Belize, of which about 600 have been discovered and excavated, many now open to tourists.


Like most Caribbean countries Belize was occupied by British and Spanish colonialists over the centuries before gaining independence (only lately recognised by neighbouring Guatemala which laid claim to the territory) in 1981. Today it is a happy-go-lucky multi-ethnic nation of warm, friendly people, very welcoming of the tourists on whom the country's economy relies heavily.


The main urban city (although not the capital) is Belize City, which offers some attractions like a world-class zoo, a new museum, historic buildings and the Maya site of Altun Ha. Basically, though, Belize is a destination for the outdoor enthusiast and adventure traveller. There are not many nightclubs, expensive shopping venues or fancy restaurants, but there is plenty of scope for diving, snorkelling, fishing, hiking, birdwatching, kayaking and exploring.

Bolivia

Salar de Uyuni © Judith Duk

Bolivia is known as the 'Tibet of the Americas', the highest and most remote of the countries in South America. It is a landlocked region with two Andean mountain ranges binding the Altiplano, or High Plain, between them. This plain has an altitude ranging from 9,000ft to 13,000ft (3,000m to 4,000m) and is where the majority of the population live.


The history of the region dates back to the pre-Columbian times, from the ancient Aymará civilisation in 1,500 BC who lived on Lake Titicaca, to the Tiahuanaco and the Inca Empire of the Altiplano, until the conquest of the Spanish in 1538. Reminders of these civilisations are evident in the architecture of the colonial cities, displayed in informative museums that can be visited at the sites of ancient ruins.


Bolivia is one of South America's more intriguing countries, as one with the most indigenous population on the continent, the majority of whom still maintain their firmly established culture and beliefs. This living historical culture is one of the reasons that Bolivia is such an exciting tourist destination. Travellers will encounter shy people in traditional clothing, colourfully dressed and red-cheeked from the mountain air. The landscape is imbued with traditional houses and age-old methods of agriculture, and visitors will find remarkable traditions kept alive in the ancient techniques of weaving, handcraft and food production. The sounds of this cultural legacy echo in the haunting melodies of the panpipes from the high Altiplano or in the lively tunes emanating from the warmer lowlands.


The dramatic geography affords many adventure opportunities: explorers can track wildlife in the Amazonian basin, drive across the surreal landscape of the Salar de Uyuni, take a boat trip on the world's highest navigable lake, Titicaca, scramble through muddy shafts in the silver mines of Potosi, or hike in the magnificent Andes mountains. There is enough diversity to meet many tastes.


The country is a juxtaposition of extraordinary altitudes and spectacular landscapes, fascinating remains of ancient civilisations, a rich indigenous culture and vast colonial treasures.

Brazil

Palms on a Brazilian beach © F H Mira

The long-lasting impression most visitors leave Brazil with is of carefree, colourful people dancing and celebrating in the street parades at Carnaval, and of a passion for life and exuberance of spirit that charms visitors from around the world. Tourists descending on the country's fabulous cities, such as hedonistic Rio de Janeiro, can enjoy the five-star hotels, shopping malls, beautiful beaches, sunny skies and inspirational restaurants without really having to confront the hundreds of shantytowns (favelas) where the poorest of the poor eke out a living in the shadows of the skyscrapers.


With booming mining, agricultural and manufacturing sectors, Brazil has the highest GDP in Latin America and is expected to be one of the world's dominant economies by the middle of this century. Brazil also caters well for business tourism and is a favoured destination for conventions, congresses and expos, particularly the city of Sao Paulo, which is the country's largest city and the business capital of Brazil.


Being so vast, larger than continental United States, Brazil offers a variety of cultures and topographies. The range is evident in the contrast of the Amazon rain forest to the mountain towns of Minas Gerais, the urban jungle of Sao Paulo and the vast central plateau around Brasilia and the world-famous beaches of Copacabana and Ipanema. It all adds up to an exotic and exciting Latin American mix where the common denominators are samba, sunshine, sultry smiles and soccer.

Chile Travel Guide

Autumn in Chile © mabahamo

A Chilean legend maintains that after God had created the wonders of the world he had many pieces leftover. He had raging rivers, sprawling glaciers, valleys and soaring mountains, snow-capped volcanoes, sparkling lakes, beautiful forests and deserts, icy fjords and sandy beaches. Rather than let all this beauty go to waste, he put them together in a remote part of the world, and so Chile was born.


Shaped like a long narrow strip and making up the western part of South America's tail, it is 2,610 miles (4,200km) in length and at most 115 miles (180km) wide. Travellers are drawn to this country because of its multitude of natural attractions, from the northern desert to the Lake District, and the mountains and fjords of Patagonia in the south. It has some superb National Parks, including Easter Island famous for its mysterious giant statues, and numerous activities for outdoor enthusiasts.


Chile's European heritage is evident throughout the country and travellers here are likely to feel more familiar with its culture than those of the neighbouring countries, with their strongly indigenous lifestyles. There are still local traditions persisting in parts of Chile however, and together with the European influence this makes for an interesting juxtaposition, providing a distinctive culture. The people are resilient, cordial and warm, from the fashionable capital city of Santiago to the isolated island of Chiloé, and Chilean hospitality is renowned.


Besides natural beauty and an interesting blend of cultures, Chile offers the visitor excellent wines and seafood, unique handicrafts and shopping, and a variety of characteristic architecture, making it a beautiful and memorable place to visit.

El Salvador Travel Guide

San Sebastian © innocacionweb

Plenty of breathtaking sightseeing opportunities await the traveller coming into this most lush of Central American nations. Lush because it's one of the most volcanic places on Earth, producing fertile soil and a thriving wilderness in its small 8,124 square miles (21,040km²).


Interspersed between the forest, mountains and 21 volcanoes are the best preserved remains of the Mayan civilisation. Joya de Cerén is all that remains of a Mayan site buried under volcanic ash 1,400 years ago and a UNESCO World Heritage Site. The San Andrés region and the ruins of Tazumal boast well-preserved structures as hallmarks to this ancient civilisation.


Getting around the small country is easily achieved by bus or taxi. The longest journey is between San Salvador to La Palma and lasts a meagre four hours, making internal flights redundant. San Salvador and San Sebastian are the main attractions. The latter is a popular picturesque beachside resort village, a town of quaint Romanesque sights and simple beauty. San Salvador, by contrast, is the hub of a rapidly industrialising country, it is densely populated and crime-ridden. Still, visitors can enjoy a wide range of sights in the city; colonial cathedrals and buildings including the Catedral Metropolitana, St Ignatius Loyola and the Spanish façade. Atop San Jacinto Mountain one can enjoy a panoramic vista of the city as well as an amusement park and cable car rides.

Honduras Travel Guide

Copan Ruins

Exuding an air of paradise with its exotic palm-fringed beaches, clear turquoise waters, majestic mountains, verdant jungles and beguiling Mayan ruins, the laid back way of life and relative obscurity to the tourist market makes Honduras an ideal holiday getaway for those who enjoy getting off the beaten track.


It has all the right ingredients for a tourist hotspot; pristine beaches, great hotels and a rich cultural history. Despite this, Honduras has scarcely registered on the Western radar in the past, other than its 15 minutes of fame in 1998 when it was ravaged by Hurricane Mitch. These days it is enjoying a boom in popularity as a relatively unknown, unspoilt and undeveloped destination, recognised for its Ecotourism opportunities, affordable scuba diving, mountain treks and river rafting, as well as its appeal to the rich and famous eager to escape the prying eye of the paparazzi.


Toucans pose alongside orchids in the humid cloud forests and mountains, while banana plantations cover the rest of the aptly named 'Banana Republic', famous for its banana cake, banana pancakes, fried plantain and banana chips. Many ancient Mayan and Lenca ruins can be found hidden away from civilisation in lush jungle landscapes, ready to enchant the most seasoned of travellers. One of the country's most breathtaking Mayan archaeological sites is the Copan Ruins, a World Heritage Site set in a verdant valley in the far western region of Honduras, reminiscent of something out of an Indiana Jones movie.


The once thriving port of Trujillo has an intriguing pirate history and exquisite tropical beaches, while the region known as the Mosquito Coast, which extends towards the Nicaraguan border, is the largest tract of tropical rainforest north of the Amazon and is one of the most popular spots in the world for ecotourism. The country also boasts 373 miles (600km) of Caribbean white sand beaches, and the offshore Bay Islands such as Utila, Roatan and Guanaja are an extremely popular destination, particularly for divers and snorkellers. There is plenty more to discover in this exciting country, however, and the warmth and hospitality of the Honduran locals is bound to lure first time visitors back time and time again.

Panama Travel Guide

Panama Canal © Panama Canal Authority

Covering a land-bridge which links North and South America, the Republic of Panama is best known for its 40-mile long (65km) shipping canal, which is cut along a gap between mountains, linking the Caribbean Sea to the Pacific Ocean. The country is largely unexplored by tourists; only a few hardy adventurers, researchers and spirited travellers have had the joy of discovering its amazing diversity of flora and fauna, secluded beaches, tropical beauty and historic treasures. The name, Panama, means 'abundance of fish and butterflies', in an indigenous language, which gives a good indication of the wild wonders to be found here, beyond its rather daunting, but fascinating capital, Panama City.



Panama has a significant history stretching back thousands of years, from its eight indigenous peoples (including the colourful Kunas of the San Blas Islands) to its turbulent colonial occupation. Spanish forts stand along the coastline, overlooking the blue waters once patrolled by famous pirates like Henry Morgan, and where Sir Francis Drake was buried at sea.


It is the natural beauty of the isthmus that offers so much for visitors, however. Around 30 percent of Panama is made up of 15 national parks and forest reserves, and 10 wildlife sanctuaries, like the incredible Parque Nacional Darién, just a short drive from Panama City, which is the most magnificent wilderness area in Central America. Archipelagos of about 1,500 offshore islands, their white soft beaches lapped by crystal clear waters, sport virgin rainforest and are an untouched paradise for divers, snorkellers, deep-sea fishing, water sports and sunbathers.


Those 'in the know' can be forgiven for keeping the delights of Panama a secret from the flood of modern tourism, because this has preserved the integrity of this overlooked part of the world where the sun always shines and it is possible to swim in two oceans in a single morning.

Venezuela

Angel Falls © angel-ecotours.com

Venezuela means 'Little Venice' in Spanish, the name given to this northerly country in South America by the early explorers when they found the natives living on the Sinamaica lagoon, in houses built on stilts, close to the present day oil rich city of Maracaibo. Lately there has been considerable political tension in the country with an attempted coup in April 2003; political demonstrations remain frequent and can often become violent. Despite this Venezuela is full of friendly, smiling people, which is hardly surprising because the country has an abundance of natural resources, including one of the biggest oil reserves in the world.


Nature has also blessed this country with diverse landscapes, from miles of beautiful Caribbean beaches to open plains, towering mountains, tracts of Amazon rain forest and even a small desert. In the southeast in Bolivar State the Gran Sabana National Park contains the spectacular Angel Falls, the world's highest waterfall.


Venezuela's cities are similarly scenic, particularly the capital, Caracas, which sprawls in a long, thin valley flanked by the majestic Avila Mountain. Caracas is lively, green and clean, with a rich cultural life, vibrant nightlife, great restaurants and marvellous modern shopping malls. A favourite excursion in Caracas is to ride the cable car to the summit of the Avila. The popular city of Merida, in the Andes, also has its cable car, and this one takes tourists on a one-hour journey to the highest point in Venezuela, the Pico Bolivar, which reaches more than 16,404ft (5,000m).


Venezuela has a little bit of everything that Latin America has to offer, with the addition of thousands of miles of Caribbean coastline, and the constantly pleasant temperature that makes it good year-round destination.

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Geographical Location and Climate

Geographical Location and Climate

Halong Bay is located in the Northeast of Vietnam, belonging to QuangNinh Province. It is in the coastal area stretching from 1060 56’ to 1070 37’ east longitude and 200 43’ to 210 09’ north latitude. To the west and northwest, Halong Bay stretches  from Yen Hung District, and includes the large urban areas of Halong City and Cam Pha Town, as well as Van Don Island District. To the south and southeast, it is adjacent to the western Tonkin Gulf and to the west and southwest lies Cat Ba Island in the province of Hai Phong.  On the world map, Ha Long Bay borders to China in the north and in the east it is adjacent to the East Sea.

In 1962, the Ministry of Culture and Information classified Halong Bay as a National Landscape Site, covering an area of 1,553 km2 with 1,969 islands. Halong Bay has  been recognized twice by UNESCO as a World Heritage Area for its universal values of landscape, geology and geomorphology, respectively in 1994 and 2000, an area of 434 sq. km. including 775 islands.

The area inscribed by UNESCO (the Protected Area I - the Core Zone) is bound by Dau Go Island in the east, Ba Ham Lake in the south and Cong Tay Island in the east. The Protected Area II - the Buffer Zone is identified by the shore of the Bay running along the National Highway No. 18A, from the Gasoline Warehouse B12 in Cai Dam Precinct to the km.11 marker in Quang Hanh Precinct, Cam Pha Town. The Protected Area III - the Hinterland Zone is the sea or mainland area surrounding the buffer zone, including the area adjacent to the Cat Ba National Park of Hai Phong City.

- Climate is featured humid tropical charactor, including two distinct seasons: hot, humid with much rainning in summer and cold, dry in winter. The average temperature ranges from 150 – 250C with annual average rainfall of 2,000 – 2,200mm/year. Halong Bay has a typical tidal time (tidal amplitude ranges from 3.5 – 4.0m. The degree of salt in the sea water ranges from 31 – 34.5% in the dry season and decreases in the rainy season.

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WHO use of advisory bodies in responding to the influenza pandemic

Pandemic (H1N1) 2009 briefing note 19

3 DECEMBER 2009 | GENEVA -- WHO is aware of some concerns, expressed in the media, that ties with the pharmaceutical industry among experts on the Organization’s advisory bodies may influence policy decisions, especially those relating to the influenza pandemic.
WHO has historically collaborated with the pharmaceutical industry for legitimate reasons. Efforts to improve health depend on better access to high-quality and affordable medicines, vaccines, and diagnostics. Medical interventions, including antiviral drugs, vaccines, and diagnostic tests, have long been recognized for their role in mitigating the health impact of an influenza pandemic. Pharmaceutical companies play an essential role in this regard and WHO has engaged with them to pursue its public health objectives.

Conflicts of interest: safeguards in place

Potential conflicts of interest are inherent in any relationship between a normative and health development agency, like WHO, and a profit-driven industry. Similar considerations apply when experts advising the Organization have professional links with pharmaceutical companies. Numerous safeguards are in place to manage possible conflicts of interest or their perception.
External experts who advise WHO are required to provide a declaration of interests that details professional or financial interests that could compromise the impartiality of their advice. Procedures are in place for identifying, investigating and assessing potential conflicts of interest, disclosing them, and taking appropriate action such as excluding an expert from participating in a meeting.

International Health Regulations

The influenza pandemic is providing the first major test of the revised International Health Regulations, which were approved by WHO Member States in 2005 and came into legal force in 2007. The Regulations provide an orderly, rules-based mechanism for coordinating the response to public health emergencies of international concern, such as that caused by the H1N1 pandemic virus.
Apart from protecting public health against the international spread of disease, the Regulations contain provisions for avoiding unnecessary interference with international travel and trade.
Under the provisions of the revised Regulations, an Emergency Committee advises the WHO Director-General on matters such as declaring a public health emergency of international concern, the need to raise the level of pandemic alert following spread of the H1N1 virus, and the need to introduce temporary measures, such as restrictions on travel or trade. Final decisions are made by the Director-General, as guided by the Committee’s advice.
All members of the Emergency Committee sign a confidentiality agreement, provide a declaration of interests, and agree to give their consultative time freely, without compensation. Members of the Committee are drawn from a roster of about 160 experts covering a range of public health areas. The framework for membership is set out in the International Health Regulations. Each State Party to the Regulations is entitled to nominate one member of the roster and additional experts are appointed by the Director-General. Recommendations of the Emergency Committee are immediately made public on the WHO web site together with the relevant decisions of the Director-General.

Strategic Advisory Group of Experts on Immunization

In responding to the pandemic, WHO has also drawn on advice from a standing body of experts, the Strategic Advisory Group of Experts on Immunization (SAGE), which advises WHO on vaccine use. Members of SAGE are likewise required to declare all professional and financial interests, including funding received from pharmaceutical companies or consultancies or other forms of professional engagement with pharmaceutical companies. The names and affiliations of members of SAGE and of SAGE working groups are published on the WHO web site, together with meeting reports and declarations of interest submitted by the experts.
Allegations of undeclared conflicts of interest are taken very seriously by WHO, and are immediately investigated.

Criticisms: understandable but unfounded

Public perceptions about the current H1N1 influenza pandemic, as well as national preparedness plans, were strongly influenced by a five-year close watch over the highly lethal H5N1 avian influenza virus, which was widely regarded as the virus most likely to ignite the next influenza pandemic. A pandemic caused by a virus that kills more than 60% of the people it infects is strikingly, and fortunately, very different from the reality of the current pandemic.
Adjusting public perceptions to suit a far less lethal virus has been problematic. Given the discrepancy between what was expected and what has happened, a search for ulterior motives on the part of WHO and its scientific advisers is understandable, though without justification.
WHO has consistently assessed the impact of the current influenza pandemic as moderate. WHO has consistently reminded the medical community, public, and media that the overwhelming majority of patients experience mild influenza-like illness and recover fully within a week, even without any form of medical treatment. WHO has consistently advised against any restrictions on travel or trade. Although influenza viruses are notoriously unpredictable, it is hoped that this moderate impact will continue throughout the duration of the pandemic.

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H1N1 immunization starts next week in Nova Scotia

With the announcement of federal authorization of the pandemic H1N1 vaccine, Nova Scotia is set to begin its biggest immunization campaign yet, Dr. Robert Strang, the province's chief public health officer, announced on Wednesday, Oct. 21.

Immunizations will get underway in this province next week.

The federal authorization order for H1N1 vaccine means the government of Canada is satisfied the vaccine is safe and effective.

Specifics of the Nova Scotia plan include:

•H1N1 vaccine will be available for free to all Nova Scotians who want it;

•People in high-risk groups for seasonal flu can get seasonal flu and H1N1 shots at the same time;

•H1N1 vaccine will be available through community clinics, some doctor offices and workplace clinics;

•Community clinics will begin across Nova Scotia over the next two weeks.

"I have every confidence that the H1N1 vaccine is safe and effective for Nova Scotians," said Dr. Strang. "I urge all Nova Scotians to get the H1N1 vaccine. It is the best way to protect yourself and your community."

Nova Scotia has ordered 1.4 million doses of the vaccine. The first shipment, 52,000 doses, arrived on Oct. 19. The province will pay about $4.5 million for the vaccine.

District health authorities are organizing community immunization clinics. Doctors will also have the option to offer the vaccine in their offices. Private nursing agencies can also get the vaccine for workplace clinics. H1N1 vaccine is also being provided to hospitals and long-term care facilities to immunize staff.

Each district health authority will organize its immunization program, including clinic dates and times. Nova Scotians should check with local district health authorities for dates and times.

"Every Nova Scotian who wants the H1N1 vaccine will be able to receive it," Dr. Strang said. "Our priority is to ensure that all Nova Scotians have the opportunity to receive the vaccine in a timely manner."

If Nova Scotians have questions about the vaccination, they can go to www.gov.ns.ca , call their local public health unit or call HealthLink 811.

Groups at high risk for seasonal flu can receive that vaccine at the same time.

"In the weeks past, we were recommending that only people above the age of 65 and those in long-term care facilities get the seasonal flu vaccine," said Dr. Strang. "Our decision was based on the best information we had available to us at that time.

"New data indicates that we can offer the vaccines concurrently. In an effort to make it easier for Nova Scotians, both the H1N1 vaccine and seasonal flu vaccine will be offered at the mass immunization clinics."

As in previous years, the seasonal flu vaccine will also be available through doctors' offices.

Signs of H1N1 activity are now starting to be seen in Nova Scotia. There have been 17 confirmed cases of H1N1 in the province since Aug. 29. There has been one death in Nova Scotia associated with the virus.

Dr. Strang continues to advise Nova Scotians to make every effort to minimize the spread of the virus. The most important step is to stay home if sick with flu-like symptoms, which are fever and/or cough with unusual tiredness, head/muscle/joint aches or sore throat.

Along with immunization, people are also encouraged to take the following precautions to prevent illness:



•Wash hands often with soap and water, especially after a sneeze or cough. When soap and water are not handy, alcohol-based hand sanitizers are an acceptable alternative.

•Cough and sneeze into elbow or sleeve.

•If using tissues, dispose of them appropriately and wash hands.

•Limit touching eyes, nose and mouth.

•Do not share drinking glasses, water bottles, mouth guards, cosmetics or eating utensils.

•If concerned that medical advice or care is needed, contact HealthLink 811. Like any illness, should symptoms worsen, visit a doctor or walk-in clinic.

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Production and availability of pandemic (H1N1) 2009 vaccines

Where are pandemic influenza vaccines being produced?

Regulatory authorities have licensed (approved) pandemic vaccines in a number of countries. The length of the approval process depends on factors such as each country's regulatory pathway, the type of vaccine being licensed, and the stage of the manufacturer's readiness to submit appropriate information to regulatory authorities.

What is the global manufacturing capacity for pandemic influenza vaccines?

As of October, WHO estimates worldwide production capacity at about 3 billion doses per year in 12 months if all available capacity is devoted to pandemic vaccine.

What technologies are being used to grow pandemic influenza viruses to make vaccines?

Most of these vaccines are being produced using chicken eggs, while a few manufacturers are using cell culture technology for vaccine production.

Will there be enough pandemic influenza vaccine for everyone?

Production of the pandemic influenza vaccines continue but in some areas demand for vaccination is greater than the supply. This gap will narrow as more vaccines become available over time.

Who will receive priority for vaccination?

WHO continues to recommend that health workers be given first priority for early vaccination to protect themselves and their patients, and help keep health systems functioning as the pandemic evolves.
Other groups at higher risk for severe illness, based on clinical studies, should also be considered as priorities. National authorities will develop and implement vaccination plans based on circumstances within the country.
These other groups include pregnant women; those aged above 6 months with one of several chronic medical conditions; healthy young adults of 15 to 49 years of age; healthy children; healthy adults of 50 to 64 years of age; and healthy adults of 65 years of age and above.

Will developing countries have access to pandemic influenza vaccines? What is WHO doing to help?

The WHO Director-General has called for international solidarity to provide fair and equitable access to pandemic influenza vaccines for all countries. So far, WHO has helped secure significant donations of vaccines from countries and partners (about 200 million doses) for 95 low- and middle-income countries. WHO's goal is to provide each of these 95 countries with enough vaccine to immunize at least 10% of its population. Deployment of the first supplies of vaccines to these countries is expected to take place from November 2009 to February 2010.

How can someone who wants to be vaccinated find out how to get immunized?

National health authorities will decide how to implement national vaccination campaigns. They will know best about whether and where pandemic influenza vaccine is available, and how to get vaccinated.

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Use of the pandemic (H1N1) 2009 vaccines

How is the vaccine given?

Some vaccines contain inactivated (or killed) viruses. These vaccines are given by injection into the upper arm for most people. In infants and younger children the thigh is the preferred site for the vaccine shot.
Another type of vaccine is made with live viruses, and it is administered by nasal spray.
Both are protective against influenza.

Do people need one dose or two doses of the vaccine?

Immunization experts recommend a single dose of vaccine in adults and adolescents from 10 years of age and above, provided this use is consistent with regulatory authorities' indications. More study is advised on effective dosage regimens for immuno-suppressed persons for whom two doses of vaccine may be needed. Where national authorities have made children a priority for early vaccination, experts are advising one dose of vaccine to as many children as possible over the age of 6 months and younger than 10 years of age. Recommendations on numbers of dosages may need to be adapted rapidly as new data emerges.

Is there anyone who should not have the inactivated pandemic vaccine?

Yes. As general rule, inactivated vaccines should not be administered to:

• People with a history of anaphylaxis (or hypersensitive reactions), or other life-threatening allergic reactions to any of the constituents or trace residues of the vaccine;
• People with history of a severe reaction to previous influenza vaccination;
• People who developed Guillain-Barré syndrome (GBS) within 6 weeks of getting an influenza vaccine;
• Children less than 6 months of age (inactivated influenza vaccine is not approved for this age group);
• People who have a moderate-to-severe illness with a fever (they should wait until they recover to get vaccinated).

Product package inserts provide information on who should not get specific vaccine products.

Can the pandemic influenza vaccine be administered simultaneously with other vaccines? What about with the seasonal influenza vaccine?

Inactivated influenza vaccine can be given at the same time as other injectable, non-influenza vaccines, but the vaccines should be administered at different injection sites.
Seasonal influenza and pandemic influenza vaccines can be administered together, and there is a public health value in doing so, according to a global panel of immunization experts. Clinical studies on this area of vaccine administration are continuing.

How can a person who wishes to be vaccinated against the pandemic influenza receive the vaccine?

National health authorities will decide how to implement national pandemic influenza vaccination campaigns. They will know best about whether and where pandemic influenza vaccine is available, and how people can get vaccinated.

Will pandemic influenza vaccines protect against other influenza viruses, such as the seasonal influenza?

The pandemic influenza vaccines are not expected to provide protection against other influenza viruses.
Since current seasonal influenza vaccines do not contain the pandemic virus, people should be vaccinated against both pandemic influenza and seasonal influenza. In the future, the situation could change.

Is there a risk of catching illness from the vaccine itself?

Inactivated vaccines contain killed viruses or parts of viruses, which cannot cause disease. Live influenza vaccine contains weakened influenza virus that multiplies poorly but is unable to cause disease.
Both vaccines can cause some flu-like side effects (e.g. muscle ache, fever) but the symptoms, sometimes associated with vaccination, are generally less pronounced and of much shorter duration.

Why do some people who have been vaccinated still get influenza?

There are some reasons why some people believe they have gotten influenza after vaccination. No vaccines, including pandemic influenza vaccines, provide 100% protection against disease. But they do greatly reduce the risk of disease. Also, influenza vaccines only become effective about 14 days after vaccination. Those infected shortly before (1 to 3 days) or shortly after immunization can still get the disease.
Vaccinated individuals can also get influenza caused by a different strain of influenza virus, for which the vaccine does not provide protection.

Finally, people who have received influenza vaccine can later have an illness, caused by other common viruses that are not influenza, but be mistaken for the flu. In all of these instances, a person could believe that the vaccine failed to protect them or that vaccine caused the disease when neither conclusion is accurate.

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Safety of pandemic (H1N1) 2009 vaccines

Safety

Are pandemic vaccines safe?

Outcomes of studies completed to date suggest that pandemic vaccines are as safe as seasonal influenza vaccines. Side effects seen so far are similar to those observed with seasonal influenza vaccines.

What about safety for pregnant women?

To date, studies do not show harmful effects from the pandemic influenza vaccine with respect to pregnancy, fertility, or a developing embryo or fetus, birthing or post-natal development. In view of the elevated risk for severe illness for pregnant women infected by the new influenza, in clinical studies, pregnant women are a group that should be vaccinated against infection, as supplies allow.
Recent studies show that infected pregnant women have a 10 times higher chance to require hospitalization in intensive care units than infected persons in the general population, and 7% to 10% of hospitalized cases are women in their second or third trimester of pregnancy. The benefits of vaccination far outweigh the risks.
Additional studies on pregnant women following immunization are continuing.

What about my child's safety from a reaction?

The most frequent vaccine reactions in children following influenza immunization are similar to those seen after other childhood immunizations (such as soreness at the injection site, or fever). A child's health care provider or vaccinator can advise on the most appropriate methods for relief of the symptoms. If there are concerns about a child's safety from a reaction, consult a health care provider as soon as possible. Please note that a child may suffer from a condition not related to immunization, which coincidentally developed after vaccination.

Testing and approval

What kind of testing is being done to ensure safety?

Because the pandemic virus is new, both non-clinical and clinical testing is being done to gain essential information on immune response and safety. The results of studies reported to date suggest the vaccines are as safe as seasonal influenza vaccines. However, even very large clinical studies will not be able to identify possible rare events that can become evident when pandemic vaccines are administered to many millions of people.
WHO advises all countries administering pandemic vaccines to conduct intensive monitoring for safety and report serious adverse events.

Who approves pandemic vaccines for use?

National authorities for medicines approve (or license) pandemic influenza vaccines for use. These authorities carefully examine the known and suspected risks and benefits of any vaccine prior to its licensing. Expedited regulatory processes in some countries have helped to license the new vaccine in a timely manner. However, the testing and manufacturing processes for the new vaccines are similar to seasonal influenza vaccines to ensure quality and safety.

Side effects

What are the expected side effects of the new vaccines?

Some side effects can be associated with influenza vaccination. How often they result depends on the type of vaccine, how it is administered, and the age of the vaccine recipient. There are two main types of vaccines: one is manufactured with inactivated viruses, the other uses live viruses.
Inactivated vaccines, administered by injection, commonly cause local reactions such as soreness, swelling and redness at the injection site, and less often can cause fever, muscle- or joint- aches or headache. These symptoms are generally mild, do not need medical attention, and last 1 to 2 days. Fever, aches and headaches can occur more frequently in children compared to elderly people.
Rarely, such influenza vaccines can cause allergic reactions such as hives, rapid swelling of deeper skin layers and tissues, asthma or a severe multisystem allergic reaction due to hypersensitivity to certain vaccine components.
Live vaccines are given via a nasal spray, and can commonly cause runny nose, nasal congestion, cough, and can less frequently cause sore throat, low grade fever, irritability and head- and muscle- aches. Wheezing and vomiting episodes have been described in children receiving live influenza vaccines.

Have clinical studies identified all the possible side effects?

Again, even very large clinical studies will not be able to identify possible rare events that can become evident when pandemic vaccines are administered to many millions of people. These can only be assessed when a vaccine is in widespread use.
Clinical trials often provide safety information for the general population. Additional monitoring of some special groups of vaccine recipients is necessary to gather specific safety information.
Additional and comprehensive monitoring efforts of the pandemic influenza vaccine are being planned as they are being used by more and more people around the world.
WHO advises all countries administering pandemic vaccines to conduct intensive monitoring for safety, and report adverse events.

Adverse events

Have their been any reports of serious reactions, or adverse events, to pandemic vaccines?

As of late October, there is no indication at this stage that unusual adverse events are being observed after immunization, according to clinical trials and adverse event monitoring during deployment of vaccines in early introducer countries. The need for continued vigilance and regular evaluation by health authorities is ongoing.

How should serious reactions to the vaccines be reported?

Reports of serious adverse events, and those raising concerns, should always be submitted to national authorities. So far, reports of potential adverse events following immunizations have been well notified to authorities.

What happens when an adverse event is reported?

At the national level, individual reports are scrutinized for completeness and possible errors. In some instances, reports need to be validated and additional details must be checked. Reports are analysed for findings that are expected or appear more frequently than expected. If an analysis indicates a potential problem, further studies and evaluation are conducted and all relevant national and international authorities are informed. Decisions for appropriate measures are then made to ensure continuing safe use of the vaccine.

Risks falsely associated with vaccines

Will pandemic vaccines contain thiomersal, which some believe is a risk to health?

Thiomersal is a commonly used vaccine preservative to prevent vaccine contamination by bacteria during use. Inactivated vaccines will contain thiomersal if they are supplied in multi-dose vials. Some products can have ''traces" of thiomersal when the chemical is used during the production process as an antibacterial agent, which is later removed during the purification process.
Thiomersal does not contain methyl mercury, which is a naturally-occurring compound and whose toxic effects on humans have been well studied. Thiomersal contains a different form of mercury (i.e. ethyl mercury, which does not accumulate, is metabolized and removed from the body much faster than methyl mercury).
The safety of thiomersal has been rigorously reviewed by scientific groups. There is no evidence of toxicity in infants, children or adults, including pregnant women, exposed to thiomersal in vaccines.

Why do some pandemic influenza vaccines contain adjuvants and others don't? Are vaccines with adjuvants a health risk?

Adjuvants are substances that enhance the immune response in vaccines and can make them more effective. They have been used for many years in some vaccines. Scientific data support the safety of adjuvants in pandemic influenza vaccine production.
Some seasonal influenza vaccines that are intended for people known to have poor immune responses to immunization contain an adjuvant. Some pandemic vaccines contain an adjuvant to reduce the amount of virus antigen to be used (an antigen is a substance capable of stimulating an immune response).
Manufacturers decide whether a product is formulated with or without an adjuvant. Adjuvants used with pandemic influenza vaccines are already licensed for use with other vaccines (e.g. hepatitis B, seasonal or pandemic influenza vaccines, or others), and have a safe track record.

Can influenza vaccination cause chronic diseases?

Current evidence does not indicate that seasonal influenza or pandemic influenza vaccines, or any other vaccine against novel human influenza viruses, either induce or aggravate the course of chronic diseases in vaccine recipients. Careful assessment is required to clarify if adverse events that occur after vaccination are actually caused by an influenza vaccination.

Can influenza vaccination cause Guillain Barré syndrome?

Guillain Barré syndrome (GBS) is a rapidly developing, immune-mediated disorder of the peripheral nervous system that results in muscular weakness. Most people recover completely but some have chronic weakness. It can develop following a variety of infections, including influenza. In people who have been immunized with available vaccines, the frequency of GBS usually is the same as in unvaccinated people. Extensive studies and data analysis of influenza vaccines have only found a well established causal association with the 1976 vaccine that contained an H1N1 swine-influenza-like virus. No other clear association has been found with either seasonal or other pandemic influenza vaccines.

How can a repeat of the 1976 swine flu vaccine complications (Guillain-Barré syndrome) experienced in the United States of America be avoided?

During the 1976 influenza vaccination campaign, about 10 persons per million vaccinated persons developed GBS.
The reason why GBS developed in association with that specific vaccine has never been firmly established. The potential for the development of a similar risk with future vaccines can never be totally excluded. However, pandemic influenza vaccines are manufactured according to established standards, and are similar to recent well-studied influenza vaccines that have shown no association with GBS. Surveillance after vaccines have been sold (post-marketing surveillance) is being conducted to look for potential developments of serious adverse events. Safety monitoring systems are an integral part of strategies for the implementation of the new pandemic influenza vaccines.

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