[binreadin]

But--how long ago had these people been vaccinated? Isn't it commonly believed that vaccinations lose their potency after 20 years or so? I know there is conflicting information on this, as studies of at least one outbreak showed that vaccinations actually protect longer than the medical community has thought true. We need more information here.

[stilts]

According to his book Biohazard, Soviet defector Alibek (one of the scientists in charge of the bio weapons program) a crucial step in weaponizing any bio agent is to make it resistent to known vaccines and treatments.