Plague Nation - Vaccination

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VACCINATION

As we've noted on the infectious diseases page the human body can fight off a number of infections on its own with its own immunity, but we are not born with a built in immunity to every disease. This is where vaccination comes in. A vaccine boosts the body's immunity by giving it a weak version of the disease causing pathogen. It tricks the body into thinking it is being attacked by the full blown disease. In so doing the body reacts and produces the antibodies to attack it. The body remembers this so that if it encounters the real disease sometime in the future, it has the defence system to fight it off.

The first vaccine was invented just over 200 years ago by an English doctor, Edward Jenner. This was one of the most important developments in the fight against infectious diseases. Now many diseases can be prevented by vaccination. There are six which are considered to be basic by the World Health Organisation - these are diptheria, tetanus, whooping cough, polio, tuberculosis and measles. These vaccines prevent the deaths of three million children a year.

Immunization has saved over 20 million lives in the last two decades.Smallpox has been eradicated and polio is on the verge of being so. Immunization rates for the six major vaccine-preventable diseases have risen from under 10 per cent in the 1970s to nearly 80 per cent today. Deaths from measles, a major killer, declined nearly two-thirds in the last decade. Immunization against tetanus saved hundreds of thousands of mothers and newborn babies, and 104 of 161 developing countries have eliminated the disease altogether.

Vaccination doesn't cost much money and is much cheaper than looking after sick people. However, more than 30 million children are unimmunized either because vaccines are unavailable, or are too expensive, or because families don't know about when and why to bring their children for immunization. In Britain recently there has been controversy about the combined MMR vaccine, with fears that it could lead to autism. This has led some parents to avoid having their children vaccinated because they have been worried that it might make them ill. This is a big problem for the government as it needs to reassure people that vaccinations are safe to protect the population as whole. The deaths of two million children worldwide could be prevented each year with proper immunisation. The more children in a community that are vaccinated, the less likely it is that any children, even the ones who haven't been immunized, will get sick because there are fewer hosts for the infectious agents. This is known as "herd" immunity.

The eradication of disease is a global issue and it needs international co-operation. It is this co-operation between various agencies that has meant that many diseases are now under control. All the time new and more powerful vaccines are being created through developments in molecular biology and genetic engineering. However, it can be an expensive business and new technologies might be prohibitively expensive for developing countries. The private companies that develop new drugs and vaccines need to pay for their research and price their products according to developed world economies. For these new vaccines to be truly effective in eradicating disease they will need to be available to all and not just to those who can afford them.

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