Over the past week, the number of new daily coronavirus cases in the United States has stopped declining even as the country's vaccination rollout continues. And more COVID-19 outbreaks are starting to be reported -- including several here in New England.
What's the cause of this seeming reversal of the recent positive trend?
There could be several reasons, according to health experts.
Dr. Ashish Jha, dean of the Brown University School of Public Health, said on Twitter that the U.S. is now at about 50,000 infections a day, which is about where we were at the height of last summer's surge.
He thinks the B.1.1.7 coronavirus variant is part of the reason, along with states continuing to relax regulations and open up their economies.
"This is a problem," Jha said.
He suggested not relaxing indoor mask mandates, not removing capacity limits on restaurants and bars and continuing to test heavily as ways to stem the tide. He also said this adds urgency to vaccinate every high risk person as quickly as possible.
"Bottom line? We are still at a high level of infection," Jha added. "Am I sure we'll see cases rise? No, but worried. Let's finish vaccinating high risk folks. Then smartly relax public health measures. That will allow us to enjoy what should be a great summer."
There is growing optimism that Massachusetts and other U.S. states may be able to reach President Joe Biden's goal of being able to have enough people vaccinated that people can gather in groups again by the Fourth of July.
Gov. Charlie Baker told The Boston Globe on Wednesday that he's becoming more confident that he can get 4 million adults vaccinated by July 4.
But some experts remain concerned that relaxing rules and regulations too soon could lead to another spike.
Dr. Philip Landrigan, director of Boston College's Program for Global Public Health and the Common Good, told the Globe that he thinks recent outbreaks are due mostly to people not taking the proper precautions to prevent the spread of the virus.
“Unfortunately, it’s easy to do," he said. "The weather is getting better. The vaccine is coming. It’s very important that people stay vigilant for a couple of more months until we get a very large portion of the population covered by the vaccine.”
Recent outbreaks have been reported at colleges across New England, and at a youth wrestling tournament in New Hampshire.
Dr. Howard Koh, a professor at the Harvard T.H. Chan School of Public Health, also urged against rolling back coronavirus regulations at this point.
"We are running a public health marathon and can't afford to stop now with the finish line in sight," he said.