'Living in danger' How scientists are parsing pandemic risks

New York: Now, even as case numbers begin to climb again and more infections go unreported, the onus has fallen on individuals to decide how much risk they and their neighbours face from the coronavirus — and what, if anything, to do about it.

For many people, the threats posed by COVID have eased dramatically over the two years of the pandemic. Vaccines slash the risk of being hospitalised or dying. Powerful new antiviral pills can help keep vulnerable people from deteriorating.

But not all can count on the same protection. Millions of people with weakened immune systems do not benefit fully from vaccines. Two-thirds of Americans, and more than a third of those 65 and older, have not received the critical security of a booster shot, with the most worrisome rates among Black and Hispanic people. And patients who are poorer or live farther from doctors and pharmacies face steep barriers to getting antiviral pills.

These vulnerabilities have made calculating the risks posed by the virus a fraught exercise. Federal health officials’ recent suggestion that most Americans could stop wearing masks because hospitalisation numbers were low has created confusion in some quarters about whether the likelihood of being infected had changed, scientists said.

“We’re doing a really terrible job of communicating risk,” said Katelyn Jetelina, an epidemiologist at the University of Texas Health Science Center at Houston. “I think that’s also why people are throwing their hands up in the air and saying, ‘Screw it.’ They’re desperate for some sort of guidance.” To fill that void, scientists are thinking anew about how to discuss COVID risks. Some have studied when people could unmask indoors if the goal was not only to keep hospitals from being overrun but also to protect immuno-compromised people.

Others are working on tools to compare infection risks to the dangers of a wide range of activities, finding, for instance, that an average unvaccinated person 65 and older is roughly as likely to die from an Omicron infection as someone is to die from using heroin for a year-and-a-half. But how people perceive risk is subjective; no two people have the same sense of the chances of dying from a year-and-a-half of heroin use (about 3 percent, by one estimate). And beyond that, many scientists said they also worried about this latest phase of the pandemic heaping too much of the burden on individuals to make choices about keeping themselves and others safe, especially while the tools for fighting COVID remained beyond some Americans’ reach.

“As much as we wouldn’t like to believe it,” said Anne Sosin, who studies health equity at Dartmouth, “we still need a society-wide approach to the pandemic, especially to protect those who can’t benefit fully from vaccination.”

While COVID is far from America’s only health threat, it remains one of its most significant. In March, even as deaths from the first Omicron surge plummeted, the virus was still the third-leading cause of death in the United States, behind only heart disease and cancer.

More Americans overall have been dying than would have in normal times, a sign of the virus’s broad toll. As of late February, 7 percent more Americans were dying than would have been expected based on previous years — a contrast with Western European nations like Britain, where overall deaths have lately been lower than expected.

How much virus is circulating in the population is one of the most important measures for people trying to gauge their risks, scientists said. That remains true even though case numbers are now undercounting true infections by a large margin because so many Americans are testing at home or not testing at all, they said.

Even with many cases being missed, the Centers for Disease Control and Prevention now places most of the Northeast at “high” levels of viral transmission. In parts of the region, case numbers, while far lower than during the winter, are nearing the peak rates of autumn’s Delta variant surge. Much of the rest of the country has what the C.D.C. describes as “moderate” levels of transmission. The amount of circulating virus is critical because it dictates how likely someone is to encounter the virus and, in turn, roll the dice on a bad outcome, scientists said. That is part of what makes COVID so different from the flu, scientists said: The coronavirus can infect many more people at once, and with people more likely to catch it, the overall chance of a bad outcome goes up.

“We’ve never seen flu prevalence — how much of it there is in the community — in the numbers we’ve seen with COVID,” said Lucy D’Agostino McGowan, a biostatistician at Wake Forest University.

Even two years into the pandemic, the coronavirus remains new enough, and its long-term effects unpredictable enough, that measuring the threat posed by an infection is a thorny problem, scientists said. Some unknown number of people infected will develop long COVID, leaving them severely debilitated. And the risks of getting COVID extend to others, potentially in poor health, who may consequently be exposed.

Still, with far more immunity in the population than there once was, some epidemiologists have sought to make risk calculations more accessible by comparing the virus to everyday dangers. Dr. Ashish K. Jha, the White House COVID response coordinator, said that the administration had helped mitigate people’s risks by making rapid tests and masks easier to get and by partnering with clinics to quickly prescribe antiviral pills. Better communication was needed to distribute preventive medicine for immuno-compromised people, he said. “We need a system that can very readily deliver therapeutics for them,” he said. “That’s very much the responsibility of government.”

Mueller is a health correspondent with NYT©2022

The New York Times