We know enough about Omicron to know we're in trouble

If there are no changes to behavior or policy, this year’s winter wave would peak at about double the hospitalizations of last winter at its worst, and 20 percent more deaths, according to the most pessimistic of projections from Meyers and her team at the University of Texas at Austin. The team gamed out a total of 18 scenarios, based on different guesses for the variant’s inherent transmissibility and immune escape, booster uptake, and the vaccines’ effectiveness against hospitalization and death. The most optimistic projection sees a caseload similar to last winter’s, but hospitalizations and deaths at about half of where they were back then, assuming the vaccines keep up their very high protection against severe illness…

The available evidence on Omicron’s inherent severity is likely to be biased in ways that make it appear more promising. First of all, hospitalizations lag infections. “Omicron has been around for three weeks,” Bhattacharyya says. “But so many of those infections have happened in the last one week of those three because of exponential growth.” Second, the first people infected may skew young and are thus more likely to have mild cases regardless of the variant. And third, some of the mildness attributed to the virus may result instead from existing immunity. In South Africa, where doctors are reporting relatively low hospitalizations compared with previous waves, many cases are probably reinfections, given that the majority of people there have had COVID before. The South Africa health-insurer data suggest that Omicron might carry a 29 percent lower risk of hospitalization than the original virus, when adjusted for risk factors including age, sex, vaccination status, and documented prior infection—but many prior infections may be undocumented, which would make the reduction in risk seem bigger than it really is. (A recent analysis of early U.K. cases found “at most, limited changes in severity compared with Delta.”) Meanwhile, Omicron is “going to spread so fast that to wait until we have definitive answers will be to wait too long,” Bhattacharyya says. “If it’s anything but the best-case scenario, and we wait to find out, it’s going to be too late to mitigate the worst.”