Covid cases in U.S. fall to levels not seen since March 2020

Confirmed coronavirus cases in the United States have fallen to levels not seen since March 2020, according to an NBC News analysis — and experts say they expect case counts to stay low through the summer.

Cases first surged in March last year, driven by a wave in New York City. That first surge peaked in April, then gradually decreased to a seven-day average of 19,000 cases June 1, 2020 — and would not fall below that threshold for the next year. On Wednesday, the seven-day average was 16,860, the lowest since March 29, 2020.

By last June, many governors had lifted the restrictions they had imposed in the spring, confident that the rest of the country would not see a surge like the one experienced in the Northeast. That was not the case: Infections surged across the South and the West last summer, and the U.S. had its most devastating surge in the winter, with daily cases exceeding 300,000 at the peak.

The winter surge has now receded, and as the calendar turns to June, the country is once again reopening. But the pandemic has changed drastically in the intervening 12 months. Thanks to vaccinations, experts say, the U.S. is unlikely to see a summer surge on a scale similar to last year.

“The level of vaccination in this country has taken any major national surge off the table,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

Bill Hanage, an associate professor of epidemiology at the Harvard T.H. Chan School of Public Health, had a similar assessment.

“We expect the summer to be relatively quiet from the combination of the high rates of vaccination, a certain amount of immunity from infection, and seasonality,” he said.

Hanage noted that current case counts may be artificially low because of Memorial Day Weekend, when fewer cases were reported. As those cases come in, some increases are expected, but he hopes the overall trend will continue downwards.

Still, both Osterholm and Hanage said that in areas with lower vaccination uptake, more localized outbreaks are likely to occur.

Certain states, like Texas, have more “patchy” vaccination uptake, Hanage said, with certain areas of the state having significantly higher vaccination rates than others. In these low vaccination areas, there will continue to be a risk for outbreaks

And outbreaks are possible in areas with higher coverage, too.

“Even if 90 percent of the people in the community are vaccinated, if the 10 percent who are not all hang out together, and the virus is introduced to them, a large proportion of them could become infected,” Hanage said.

The big test will come in the fall, when the weather cools and people start to gather indoors, said Dr. Chris Beyrer, a professor of epidemiology at Johns Hopkins Bloomberg School of Public Health. The virus spreads much more easily in indoor, poorly ventilated spaces.

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Still, Hanage noted, any fall or winter uptick won’t be like the surge the nation saw last winter, because the vaccines have proven to be very effective in preventing severe disease. That means an increase in cases won’t necessarily lead to a large increase in hospitalizations seen in previous surges, he said.

What ultimately happens in the fall, Beyrer said, is up to the American people.

“We've got to get as high of coverage with these terrific vaccines as we can, as that’s the key to whether or not we have another fall where we see outbreaks and infections,” he said.

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