Pretty scary stuff

[Plane]

Catch an English cat, catch cowpox.

Cowpox is similar to but much milder than the highly contagious and sometimes deadly smallpox disease.[1] It resembles mild smallpox, and was the basis of the first smallpox vaccines. When the patient recovers from cowpox, the person is immune to smallpox.
 
The cowpox virus was used to perform the first successful vaccination against smallpox, which is caused by the related Variola virus. ..............................Despite the eradication of smallpox in the past century, other orthopoxviruses, such as monkeypox virus, vaccinia virus in Brazil, and cowpox virus (CPXV) in Europe, still infect humans.

http://en.wikipedia.org/wiki/Cowpox

The virus is found in Europe, and mainly in the UK. Human cases today are very rare and most often contracted from domestic cats. The virus is not commonly found in cattle; the reservoir hosts for the virus are woodland rodents, particularly voles. From these rodents, domestic cats contract the virus. Symptoms in cats include lesions on the face, neck, forelimbs, and paws, and less commonly upper respiratory tract infections.[7] Symptoms of infection with cowpox virus in humans are localized, pustular lesions generally found on the hands and limited to the site of introduction. The incubation period is 9 to 10 days. The virus is prevalent in late summer and autumn.