Via her superb blog Superbug, Maryn McKenna discusses the big story of the day: Virus in Found Tubes of Smallpox Is Viable. After a detailed but concise account of the discovery of the vials and the CDC's response, she concludes:
It’s worth asking: If someone had been exposed to the vials’ contents, what would have happened? Under natural circumstances — which haven’t existed for 37 years — people became infected either from close face-to-face contact with another infected person, or through contact with household items or pox scabs bearing the virus. (There’s a surprising amount of discrepancy in the old literature — most of which is not digitized — about how likely an exposure would be to cause an infection.)
Assume though that someone did become infected: Smallpox takes a while to develop, and has a unique set of symptoms even before the characteristic rash develops, making it easily detectable if a physician thinks to look for it.
If this hypothetical person was vulnerable (possible, because there has been no vaccination in the US general population since the 1970s) and did develop smallpox, it would be exceedingly bad for them: Smallpox killed at least one in four who contracted it. But that person might be the only victim: there is a significant vaccine stockpile, about 220 million doses, that could be deployed to create a cordon sanitaire around the case and choke off any further spread.
That is not to say that a case of smallpox would be a minor matter. It would be a dreadful thing to bring an extinguished disease back into the world again. And the panic, if news got out, would no doubt be an uproar. When a traveler brought smallpox to New York City in 1947, causing an outbreak that killed two and infected 12 others, 6 million people demanded to be vaccinated, standing in line for days.
As Frieden said today, “These events should not have happened.” With good fortune, they won’t happen again.