Americans seem to have heeded the expert advice since then. “It’s likely that the population is more fearful and adhering to public-health advice more, like masking and distancing,” Gostin said.

This extra caution only bolsters the benefits of vaccination and the immunity that lingers after people recover from COVID. So far, states have administered 65 million doses of two different two-dose vaccines. Meanwhile, no fewer than 27 million Americans have caught and recovered from COVID, giving them some degree of immunity for at least a few months, in most cases.

“We are seeing chains of transmission being broken,” Gostin said. As a result, the worst-case scenarios initially imagined in light of the new mutations haven’t come true. In most of the countries and states that have given rise to new, theoretically more-transmissible variants, cases are falling—fast.