Plummeting cases in U.S. show path to crushing COVID-19

COVID-19 cases and hospitalizations are dropping dramatically across the U.S., suggesting that measures to interrupt transmission are working, at least for now.

More than 27.6 million Americans have tested positive, likely giving them some degree of immunity. A rising number — 11.8 percent of the population — has now received at least one dose of a vaccine. And data gathered from mobile phones suggest people are being more cautious day-to-day. If cases keep falling, it could buy time for the vaccination effort to take hold in the warm summer months ahead, potentially underpinning a longsought economic recovery.

Health experts, though, anticipate challenges. Inoculations need to outpace highly contagious variants from the U.K. and South Africa that are now in the U.S. And the upcoming holidays — spring break, Easter and Mother’s Day included — hold the threat of group gatherings that can swiftly boost the virus’ spread.

“The history of surges is they do come down,” said Robert Wachter, chair of the department of medicine at the University of California-San Francisco. “They generally come down from some combination of changes in behavior, changes in government policy and the impact of immunity.”

Rochelle Walensky, head of the U.S. Centers for Disease Control and Prevention, on Sunday rang a warning bell. “We are nowhere out of the woods,” she said on CBS’ “Face the Nation,” adding that “now is the time to double down” on mitigation efforts.

If those efforts are relaxed “with increasingly transmissible variants out there,” she said, “we could be in a much more difficult spot.”

At the present vaccination rate, enough doses will have been administered by Spring Break in mid-March to cover about 15 percent of the U.S. population with two doses, according to the Bloomberg vaccine tracker. By Easter Sunday, that will rise to about 20 percent and by Mother’s Day enough shots could be given to cover close to 30 percent of Americans. And these estimates, based on vaccination rates over the last week, should rise substantially as more vaccine supply becomes available.

Eventually, COVID-19 may reach an endemic state and become seasonal like other coronaviruses, the common cold and influenza, said Brian Fisher, a senior scholar at the Penn Center for Clinical Epidemiology and Biostatistics. The endemic state will still need to be addressed with vaccines, he said, including updated ones.

“Now, how we get there is up for debate, and there likely will be some increased periods of increased transmission still ahead,” he said.