Except very few, if any (?), vaccines work that way. And if they don't, it's not the vaccine's fault. It's the virus' fault. Some mutate more often than other, i.e flu, cold. Others don't. Or mutate in a way that makes them less virulent (measles, apparently).
So this is a tall order for any vaccine. I just don't understand the push for perfection. And look, I get these vaccines aren't perfect either, but they are the best we got.
While the influenza virus mutates constantly and requires a yearly shot that offers a certain percentage of protection, old reliable measles needs only a two-dose vaccine during childhood for lifelong immunity. A new study has an explanation: The surface proteins that the measles virus uses to...
www.sciencedaily.com