When Will the Outbreak Be Over?

At the Atlantic Alexis C. Madrigal reflects on when the outbreak of COVID-19 will be over in the U. S.:

The most obvious interpretation of “beating COVID-19” would be that transmission of the coronavirus has stopped, a scenario some public-health experts have hashtagged #ZeroCOVID. But the experts I spoke with all agreed that this won’t happen in the U.S. in the foreseeable future. “This would require very high levels of vaccination coverage,” said Celine Gounder, an infectious-disease specialist at NYU who served on Joe Biden’s coronavirus task force during the transition. The U.S. may never reach vaccination rates of 75 to 85 percent, the experts said.

“The question is not when do we eliminate the virus in the country,” said Paul Offit, the director of the Vaccine Education Center and an expert in virology and immunology at the Children’s Hospital of Philadelphia. Rather, it’s when do we have the virus sufficiently under control. “We’ll have a much, much lower case count, hospitalization count, death count,” Offit said. “What is that number that people are comfortable with?” In his view, “the doors will open” when the country gets to fewer than 5,000 new cases a day, and fewer than 100 deaths.

That latter threshold, of 100 COVID-19 deaths a day, was repeated by other experts, following the logic that it approximates the nation’s average death toll from influenza. In most recent years, the flu has killed 20,000 to 50,000 Americans annually, which averages out to 55 to 140 deaths a day, said Joseph Eisenberg, an epidemiologist at the University of Michigan. “This risk was largely considered acceptable by the public,” Eisenberg said. Monica Gandhi, an infectious-disease specialist at UC San Francisco, made a similar calculation. “The end to the emergency portion of the pandemic in the United States should be heralded completely by the curtailing of severe illness, hospitalizations, and deaths from COVID-19,” she said. “Fewer than 100 deaths a day—to mirror the typical mortality of influenza in the U.S. over a typical year—is an appropriate goal.”

Another yardstick that has been proposed is by number of newly-diagnosed cases:

Some experts were even more conservative. Crystal Watson, a health-security scholar at Johns Hopkins University, suggested a threshold of 0.5 newly diagnosed cases per 100,000 people every day, and a test-positivity rate of less than 1 percent. That would translate to fewer than 2,000 cases a day in the U.S., compared with the current 60,000 or more. We’d also want to log at least one month of normal hospital operations without staff or equipment shortages, she said.

which I find a bit facetious. As the ability to diagnose cases becomes more effective shouldn’t it shorten the duration of the outbreak? That wouldn’t necessarily be the case.

You would think that after nearly a year of a global pandemic there might be more agreement about when it was no longer a pandemic and when local outbreaks were over. Apparently not. Keep in mind that in some countries, e.g. New Zealand, Australia, and Singapore, the outbreaks are already materially over. In other, including the U. S., it will certainly be many months and might even be years before the present outbreaks are over. That in turn implies that, unless much more stringent bans on international travel are imposed than have been the case to date, the global pandemic will not be over for a very long time.