What is a Yellow Fever Vaccination?

A yellow fever vaccination is an injection designed to make a traveler immune to yellow fever. This disease is found in tropical areas of Africa and South America. It is spread by the bites of mosquitoes. Mosquito control can help prevent transmission of this potentially deadly disease. Being treated with a vaccine for the disease, however, is the safest way to avoid contracting yellow fever.

There is no cure for this viral disease, and treatment is based on its symptoms. Since yellow fever is spread by mosquitoes, it can cause devastating epidemics. It has been eradicated in some parts of the world with the help of a vaccine that has been in use since the 1950s.

There are two strategies of vaccine use. One is to use a microorganism that has been altered so it cannot cause disease. The use of a live, but inactive microbe, for vaccine administration is known as its having been attenuated. This is the case for the yellow fever vaccination. In other types of vaccinations, pieces of the organisms are used that are known to be recognized by the body’s immune system.

The immune system produces antibodies — millions of different Y-shaped molecules that recognize foreign invaders in the body. If a pathogen is new and not recognized by a person’s antibodies, disease can occur. Treatment ahead of time with small amounts of the pathogen can prime the immune system, which can create new antibodies to recognize the foreign organism. If faced with the same organism in the future, it will remember the invader and mount a large assault against it. Ideally, this will prevent disease.

Like all injections of this kind, there are risks associated with yellow fever vaccination. They are generally uncommon, however. Certain classes of people should not be vaccinated. Children under six months old should never receive the vaccine. It is also not advised for pregnant women, but it is worse for the unborn baby to get yellow fever than to get the vaccine.

It is common for people who are allergic to eggs to have difficulty with vaccines because eggs are used to create the medication. It may be possible for these people to receive the immunization in several smaller doses, however. People who have problems with their immune systems, such as people with AIDS, are more likely to suffer adverse results from the injection. People who are elderly are also much more susceptible to negative reactions. According to the United States Centers for Disease Control and Prevention (CDC), those 60 years old or over are five to six times more likely to suffer highly adverse complications from yellow fever vaccination.

For most people, the odds of contracting a side effect from the vaccine are very low. Yellow fever is a life-threatening disease. Thus, most doctors strongly advise yellow fever vaccination for those aged nine months or older, who will be traveling in areas where one might contract the disease. The vaccination schedule involves a single initial vaccine injection. Its effects last for ten years, after which one should obtain a booster shot.

Many countries require proof of yellow fever vaccination before they allow a visitor into the country. After vaccination, a yellow card is typically issued. This lists the date of the shot and is valid beginning ten days after it is administered, and remains so for ten years. Even having had a yellow fever vaccination, one should still take precautions against mosquito bites in areas where contracting yellow fever is a possibility.