Since Americans first rolled up their sleeves for coronavirus vaccines, health officials have said those immunized are highly unlikely to become infected or suffer serious illness or death. But preliminary data from seven states suggests that the arrival of the Delta variant in July may have changed the calculus.
According to figures compiled by NewsMadura, breakthrough infections in vaccinated people accounted for at least one in five newly diagnosed cases in six of those states and higher rates of total hospitalizations and deaths than had been previously observed in all states.
However, absolute numbers remain very low and there is little doubt that the vaccines remain potently protective. This remains “an unvaccinated pandemic,” as federal health officials have often said.
Still, the trend marks a change in how vaccinated Americans might view their risks.
“Remember when the early vaccine studies came out, it was like nobody was hospitalized, nobody died,” said Dr. Robert Wachter, chair of the department of medicine at the University of California, San Francisco. “Obviously that’s not true.”
The numbers support the view, widely held by officials in the Biden administration, that booster shots may benefit some Americans in the coming months. Federal officials plan to authorize additional shots as early as mid-September, although it is not clear who will receive them.
“If the probability of a breakthrough infection has risen significantly, and I think the evidence is clear that they have, and the level of protection against serious disease is no longer as robust as it used to be, I think the case for boosters is pretty good. goes up. quickly,” said Dr. watchman.
The seven states — California, Colorado, Massachusetts, Oregon, Utah, Vermont and Virginia — were surveyed because they hold the most detailed data. It is not certain whether the trends in those states will hold up throughout the United States.
In any case, scientists have always expected that as the population of vaccinated people grows, they will be more often represented in the numbers of seriously ill and dead.
“We don’t want to water down the message that the vaccine is hugely successful and protective, any more than we initially hoped,” said Dr. Scott Dryden-Peterson, infectious disease physician and epidemiologist at Brigham & Women’s Hospital in Boston.
“The fact that we’re seeing groundbreaking cases and groundbreaking hospitalizations and deaths doesn’t change the fact that it’s still saving the lives of many people.”
The CDC declined to comment on the states’ numbers. The agency is expected to discuss breakthrough infections, hospitalizations and vaccine effectiveness at a news conference on Wednesday.
Most breakthrough infection analyzes contain figures collected up to the end of June. Based on the cumulative numbers, the CDC and public health experts had concluded that breakthrough infections were extremely rare and that vaccinated people were highly unlikely to become seriously ill.
The data from the states does confirm that vaccinated people are much less likely to become seriously ill or die from Covid-19.