As Omicron Surges, a Race to Gauge the Threat

The good news, experts said, is that America has resources at its disposal, if it chooses to use them. Tests still work for Omicron. Vaccines are now widely available and could blunt the burden of severe disease. Antiviral pills, which are expected to work against Omicron, could soon be available, although supplies will be very limited at first.

“There are more tools in our toolbox now than there were during the holiday season last year,” Dr. Majumder said.

People who are not yet vaccinated should get vaccinated, experts said, and those who are eligible for boosters should get them. And masking, testing and taking precautions when gathering with others indoors — the same behaviors that experts have long been recommending — can also help slow the spread.

But beyond these individual behaviors, officials still need to do more, experts said.

The Biden administration, for instance, has focused heavily on promoting vaccination and boosters, which remain critical public health tools. But in the face of a foe like Omicron, they are not enough, experts warned.

“The way we’re seeing it unfold in other places, the way we’re starting to see it take hold here, implies that a vaccination-only strategy is going to be very fragile,” Dr. Salomon said.

Experts called on officials to improve access to testing, distribute high-quality masks, promote improved ventilation and issue clearer guidelines about what activities it is safe to engage in and in what circumstances.

Local governments, schools and employers also need to begin making plans — and making those plans public — about what they will do in the event of large outbreaks or if cases or hospitalizations rise to a certain level, they noted.