Cowpox

Cowpox is a disease that affects the skin and causes red blisters. It can affect people or animals. It is caused by the cowpox virus, which is related to the Vaccinia virus. It can be spread by touch from cows to humans. 

Edward Jenner used the cowpox virus to make the world's first successful vaccination against smallpox, an extremely deadly disease. Smallpox is caused by the related variola virus. Therefore, the word "vaccination" has the Latin root vaca, meaning cow.

 Epidemiology 
The Cowpox virus (also called Catpox) is found in Europe, mainly in the United Kingdom.  

Despite its name, the virus is not commonly found in cows. Usually woodland rodents, particularly voles, carry and spread the virus.  When domestic cats get the virus from these rodents, they can pass it along to humans.  Most human cases are caused by contact with infected domestic cats.

 Symptoms 
Symptoms in cats include lesions on the face, neck, forelimbs, and paws. Less commonly, cowpox can cause upper respiratory tract infections in cats.  

In humans, symptoms of cowpox infection occur only in the body part where the virus was introduced. Usually, this is the hands, and pustular lesions form there. 

The incubation period (the time between an infection and the first signs of the disease) is 9–10 days.  The virus can be found mostly in late summer and autumn.

Historical use
Cowpox was the original vaccine of sorts for smallpox. In 1798, the English physician Edward Jenner noticed that farmers who had recovered from cowpox usually did not get cowpox again - or smallpox. So he used the fluid he got from cowpox lesions, and scratched it into healthy people. That way, he could make those people immune against smallpox.

After infection with cowpox, the body (usually) gains the ability recognise the similar smallpox virus from its antigens. Because it recognizes the virus, the body can fight smallpox much more efficiently.

Later, and still today, another vaccine was used: vaccinia. Vaccinia is similar to cowpox, but not the same.

Related pages
Chickenpox
List of diseases

References

Category:Diseases caused by viruses
Category:Animal diseases