It would be for the worse thing they're going to release later

See, I don't buy that, for the point of my earlier remark that biology is messy. I'll explain, using Rainbow Six.

In Rainbow Six, some ecoterrorists engineer the shiva virus in three parts. The first is a fairly weak version intended to sow panic, then a real vaccine (for themselves) and a fake vaccine that's intended to kill everyone else off.

In REALITY, once shiva is out in the wild you can't count on ANY vaccine you invented for it to be reliable. You wouldn't make a biological weapon so deadly that you're counting on the vaccine to save your ass, because it probably won't once the virus has a chance to stretch its legs.

But you could rely on antibody-dependent enhancement. That is, you release a virus, deploy a "vaccine" (the first part of the binary weapon, which creates a corrupted antibody) and then release another virus (the second part of the binary weapon). This would be slightly safer in the wild than Shiva, you wouldn't expect it to evolve to such a degree that it would be come dangerous to people who didn't have both binary parts.

Anyway...

they want the people that will listen to them to survive

I don't assume that. It wasn't the workers the Soviets sent to the Siberian death camps. It was the revolutionaries.

It would be for the worse thing they're going to release later

See, I don't buy that, for the point of my earlier remark that biology is messy. I'll explain, using Rainbow Six.

In Rainbow Six, some ecoterrorists engineer the shiva virus in three parts. The first is a fairly weak version intended to sow panic, then a real vaccine (for themselves) and a fake vaccine that's intended to kill everyone else off.

In REALITY, once shiva is out in the wild you can't count on ANY vaccine you invented for it to be reliable. You wouldn't make a biological weapon so deadly that you're counting on the vaccine to save your ass, because it probably won't once the virus has a chance to stretch its legs.

But you could rely on antibody-dependent enhancement. That is, you release a virus, deploy a "vaccine" (the first part of the binary weapon) and then release another virus (the second part of the binary weapon). This would be slightly safer in the wild than Shiva, you wouldn't expect it to evolve to such a degree that it would be come dangerous to people who didn't have both binary parts.

Anyway...

they want the people that will listen to them to survive

I don't assume that. It wasn't the workers the Soviets sent to the Siberian death camps. It was the revolutionaries.