A Vaccine Doesn’t Need to Be Perfect to Be Valuable

What if a vaccine is closer to 50% effective against the novel coronavirus? In The Atlantic, James Hamblin, MD, has a great explainer for why even a vaccine with lower effectiveness could be a useful tool. He writes:

If everyone in a population takes a vaccine that is, say, 70 percent effective, the effects add up quickly. The result is a population that is protected — and that more quickly achieves “herd immunity” than a population with a less effective vaccine. Occasional cases of Covid-19 might arise, but enough people will not contract…