The coronavirus won’t be loosening its grip on the United States any time soon, leading infectious disease experts said on Sunday. They are also uncertain how the viral spread will be affected by the patchwork of states reopening businesses and by large events like protests and President Trump’s upcoming campaign rallies.
“This virus is not going to rest” until it infects about 60 percent to 70 percent of the population, Dr. Michael T. Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said on “Fox News Sunday.”
Experts have estimated that without a vaccine, about 70 percent of the population will need to be infected and develop immunity in order to stop the virus’s spread, a concept called herd immunity. The number of confirmed American cases now exceeds 2 million, less than 1 percent of the U.S. population, according to the Johns Hopkins Covid-19 Dashboard and the Centers for Disease Control and Prevention.
Joseph Fair, a virologist and epidemiologist who recently recovered from a serious bout of Covid-19, echoed that view on NBC’s “Meet the Press.”
“Once it gets so ingrained in the population, there’s not a point where we can come back from that other than having a vaccine in place,” said Dr. Fair, who is a medical contributor to NBC News.
Dr. Osterholm said that recent data show the rate of new cases has been level in eight states, increasing in 22 states and decreasing in the rest. The increase is not simply because of more widely available testing, the experts said, noting that an especially worrisome development is a rise in hospitalizations in several states.
“At this point, hospitals are at risk of getting overwhelmed and that is basically signaling to me that those states are already behind,” said Dr. Nahid Bhadelia, medical director of the special pathogens unit at Boston University School of Medicine, who also appeared on the NBC News program on Sunday.
The C.D.C. recently projected that by July 4, coronavirus deaths in the United States will likely jump from the current level of about 115,000 to somewhere between 124,000 and 140,000.
Dr. Bhadelia said the rise in cases in some states, especially in the South and West, suggested that “we opened too early in those states. We didn’t have the ability to basically trace down those chains of transmission and stop them once people started mingling again.”
But Dr. Osterholm said the reasons are still unclear. “Do we think reopening is going to increase cases? Sure should. But we have examples of states where it hasn’t happened,” he said, adding, “We don’t really know what is actually making the virus move like it is right now in some states and not others.”
He said that so far there have not been widespread indications that protests over police killings of African-Americans and racial injustice have led to a spike in cases. He pointed out that because the virus has an incubation period of up to two weeks, any such effect will become clearer in the coming days. He and other experts have noted that the BlackLivesMatter protests are taking place outdoors and that many participants are wearing masks, steps expected to limit the spread of the virus.
“On the other hand, yelling, screaming, being exposed to tear gas or smoke, which causes coughing, being put into a holding cell overnight in jail if you’re arrested — all are reasons why you would expect to see more cases,” Dr. Osterholm said.
The risk of viral spread at a rally like the one President Trump has planned for next weekend in Oklahoma is much higher, the experts said, because the rally will be indoors in a large arena and there will no requirement that attendees wear masks.
“It’s a perfect storm setup: the idea of tons of people, where one sick person can have an impact of generating secondary cases on this immense level, where it’s indoors, where there’s no ventilation,” Dr. Bhadelia said. “I would move it to the outdoors, I would reduce the number of people, I would introduce social distancing, and I would require everybody to wear a mask.”