The Aralsk test killed bunches of people who were:
A - wearing suits/protection
B - vaccinated to the gills
The only reason it stopped was that the main effect was out to sea, and that the affected land area was isolated so the thing burned itself out.
Vaccines are ineffective against weaponized microbes. And, these days, any college grad student has plenty of knowledge of how to alter these microbes and access to the equipment to do it. The push to vaccinate kids against anthrax in the event of a terrorist event is a non starter. Any terror event likely will use genetically altered anthrax. Otherwise, why bother...
Microbe weaponization is just one stop on the whole ‘just because we can, should we?’ road to perdition.