And if this vaccine doesn't work or has nasty side effects, or even ends up killing people, most people will be very reluctant to take it, or any of the next be

And if this vaccine doesn't work or has nasty side effects, or even ends up killing people, most people will be very reluctant to take it, or any of the next better vaccines, and that would cause even more deaths. It's a hard problem, and even though the clock is ticking, we also need to get it right the first time.