> "We don't know exactly why or how it works, we just know that it does work," says Michael Kinch, an associate vice chancellor at Washington University in St.

> "We don't know exactly why or how it works, we just know that it does work," says Michael Kinch, an associate vice chancellor at Washington University in St. Louis who has written a book on vaccination. Kinch and others suspect this form of inoculation may have worked because it introduced the smallpox virus through the skin, rather than the lungs. This is really interesting, I wonder if we have any evidence of similar behavior of other viruses?