Vaccinia vaccine

Vaccinia vaccine is a vaccine that was used to provide immunity against smallpox. It was the first vaccine to be developed and its use led to the eradication of smallpox in 1980. The vaccine is no longer given as a routine immunization, as smallpox is considered eradicated, but it is still used in certain high-risk populations.

History

The vaccinia vaccine was developed by Edward Jenner in 1796. Jenner discovered that milkmaids who had contracted cowpox, a disease similar to smallpox, did not get smallpox. He hypothesized that the cowpox protected them from the more deadly disease. To test his theory, he inoculated a boy with cowpox and then exposed him to smallpox. The boy did not get sick, proving Jenner's theory correct.

Production

The vaccinia vaccine is produced by infecting cows with the vaccinia virus. The virus is then harvested from the cow's skin, purified, and made into a vaccine. The vaccine is a live virus vaccine, meaning it contains a live, weakened form of the virus.

Administration

The vaccinia vaccine is not given as a shot like most vaccines. Instead, it is given using a bifurcated (two-pronged) needle that is dipped into the vaccine solution. The needle is then used to prick the skin a number of times in a few seconds. The pricking is not deep, but it will cause a sore spot and, later, a blister to form.

Side Effects

Like all vaccines, the vaccinia vaccine can cause side effects. The most common side effect is a sore arm where the vaccine was given. Other side effects can include fever, rash, and headache. In rare cases, the vaccine can cause more serious side effects, such as inflammation of the heart or heart-related problems.

Current Use

Today, the vaccinia vaccine is not used as a routine immunization because smallpox has been eradicated. However, it is still used in certain high-risk populations, such as laboratory workers who work with the virus or members of the military who might be exposed to the virus as a biological weapon.