In a Handful of States, Early Data Hint at a Rise in Breakthrough Infections

With the arrival of the contagious Delta variant, Covid hospitalizations and deaths among vaccinated Americans also may have increased, according to preliminary figures.

Since Americans first began rolling up their sleeves for coronavirus vaccines, health officials have said that those who are immunized are very unlikely to become infected, or to suffer serious illness or death. But preliminary data from seven states hint that the arrival of the Delta variant in July may have altered the calculus. Breakthrough infections in vaccinated people accounted for at least one in five newly diagnosed cases in six of these states and higher percentages of total hospitalizations and deaths than had been previously observed in all of them, according to figures gathered by The New York Times. The absolute numbers remain very low, however, and there is little doubt that the vaccines remain powerfully protective. This continues to be “a pandemic of the unvaccinated,” as federal health officials have often said.