@Oleander209 @DrEricDing @IntegralAnswers Nobody is really sure how effective it is after so many years. If you were potentially going to be exposed (say working on a smallpox lab) you'd be getting boosters.
@夹竹桃209@drericing@IntegralAnswers这么多年后，没有人真正确定它有多有效。如果你有可能被感染（比如在天花实验室工作），你就会得到助推器。