Scrambling for answers on omicron

Scientists around the world are racing to understand the omicron variant, and there are some clearer signs than a week ago.

David LeonhardtThe New York Times
Published : 8 Dec 2021, 05:51 AM
Updated : 8 Dec 2021, 05:51 AM

With help from experts, we will try to answer four questions about omicron. But there’s a caveat: There is still a lot of uncertainty about almost every aspect of the variant.

Does omicron spread faster than earlier variants?

Yes, in all likelihood.

The number of COVID cases is soaring in South Africa, for example. It’s still possible this will be a mirage — and that the world is confusing a more normal surge in cases (and surges often happen for unclear reasons) with the effects of a new variant. But the evidence for faster spread of omicron seems strong.

“The omicron variant is spreading more quickly than delta,” Janet Baseman, an epidemiologist at the University of Washington, said. Dr Rebecca Wurtz of the University of Minnesota said, “omicron is more contagious.”

The bigger unknown is why it’s spreading rapidly, and there are two plausible answers. The first is that omicron spreads more easily among people with no immunity — those who are unvaccinated and were not previously infected by COVID. The second is that omicron more often evades immunity, allowing it to spread more among people who were vaccinated or previously infected.

Both explanations could be true, and many scientists think they both probably are. But the facts are not clear. “Bottom line: Not much doubt that omicron spreads faster than Delta; we’re still not 100% sure why,” Dr Robert Wachter of the University of California, San Francisco, said.

The apparent contagiousness of omicron means that it presents an even more serious threat to the unvaccinated than COVID already did. And the threat was already dire. About 1,000 Americans have been dying each day of COVID in recent weeks, the vast majority of them unvaccinated.

Is omicron more severe than earlier variants?

No, in all likelihood. But there is less consensus on this question.

Some scientists think it’s simply too early to know whether the average person who contracts omicron becomes sicker than the average person who contracted earlier versions of the coronavirus. “It’s all speculation at this point,” Dr Paul Sax of Brigham and Women’s Hospital in Boston told me.

Severe illness often takes a week or more to develop, and the world has been aware of omicron for less than two weeks. “We may just not have had enough time to see severe disease develop,” Dr Aaron Richterman of the University of Pennsylvania said. The early studies of omicron patients have also come disproportionately from South Africa, where the population skews young and many people were previously infected with delta.

“What is hard to assess right now,” epidemiologist Jennifer Nuzzo of Johns Hopkins University said, “is how this will play out if or when older and more vulnerable people become infected.”

Other scientists believe that the early signs are clearer and more positive. If anything, they say, omicron looks milder than previous variants. Hospitalisation and death rates in South Africa have not soared even as cases have. Intriguingly, patients are reporting less loss of taste and smell.

Dr David Dowdy, another Johns Hopkins epidemiologist, said he happened to have a close research collaboration with scientists in Tshwane, a South African city at the epicentre of the outbreak. His colleagues there have said hospitalisations and oxygen demand are lower than during previous waves. “I think the signs are actually extremely optimistic,” he said.

You’ll hear some similar messages in Bloomberg interviews with South African scientists. “It’s early days, but I’m less panicked,” said Richard Friedland, chief executive of the country’s largest network of private health care providers. “It feels different to me on the ground.”

If nothing else, I think it’s a mistake to assume that omicron is more severe than earlier versions of the virus — as people often do when they hear about a new variant. “The signals are a bit encouraging regarding the severity,” Dr Anthony Fauci, the White House adviser, said this weekend on CNN.

So are vaccinated people protected or not?

The answer depends on the meaning of “protected.”

The early evidence suggests that omicron may indeed be more likely to infect vaccinated people than earlier versions of the virus. Yet there is still no sign that omicron will cause vaccinated people to get more severe versions of COVID.

“I do think vaccines will hold up, not so much for getting infections but for severe illness,” Dr Eric Topol of Scripps Research said. Dowdy, of Johns Hopkins, put it this way: “Our immune systems are designed to protect us from getting sick, not from getting any infection whatsoever.”

The situation may be similar for unvaccinated people who have had a prior infection — or they may be more vulnerable to serious COVID. It’s not clear.

One worrisome postscript is that even seemingly mild COVID infections can prove deadly for vulnerable people, like the elderly. A second problem is the increasing evidence of waning immunity among the vaccinated and previously infected. “Our effective vaccination rate is dropping,” Topol noted.

All of this argues for getting vaccinated, even if you have been infected, and getting boosted, if you’re eligible.

Do COVID tests still work?

Yes, based on the signs so far. Assuming that remains true, it will be very helpful. “Omicron’s spread will put a much greater premium on rapid testing, as will the new oral drugs,” Wachter said.

The bottom line

The early signs may prove misleading, and we will know more within a few weeks.

For now, vaccinated people can reasonably continue to behave as they were — but should probably feel more urgency about getting booster shots. Older people and others who are vulnerable should continue to be careful and ask people around them to test frequently.

Unvaccinated people remain at risk of fatal illness, and one in six American adults still has not received a shot.

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Editor-in-Chief and Publisher