By David Leonhardt, NY Times

The public reaction to new Covid-19 variants has followed a familiar cycle. People tend to assume the worst about two different questions — whether the variant leads to faster transmission of the Covid virus and whether it causes more severe illness among infected people.

The first of those worries came true with the Alpha and Delta variants: Alpha was more contagious than the original version of the virus, and Delta was even more contagious than Alpha. But the second of the worries has largely not been borne out: With both Alpha and Delta, the percentage of Covid cases that led to hospitalization or death held fairly steady.

This pattern isn’t surprising, scientists say. Viruses often evolve in ways that help them flourish. Becoming more contagious allows a virus to do so; becoming more severe has the potential to do the opposite, because more of a virus’s hosts can die before they infect others.

It is too soon to know whether the Omicron variant will fit the pattern. But the very early evidence suggests that it may. Unfortunately, Omicron seems likely to be more contagious than Delta, including among vaccinated people. Fortunately, the evidence so far does not indicate that Omicron is causing more severe illness:

• Barry Schoub, a South African virologist who advises the government there, has said that Omicron cases have tended to be “mild to moderate.” Schoub added: “That’s a good sign. But let me stress it is early days.”
• Dr. Rudo Mathivha, the head of the intensive care unit at a hospital in Soweto, South Africa, said that severe cases have been concentrated among people who were not fully vaccinated.
• Dr. Sharon Alroy-Preis, a top health official in Israel, emphasized yesterday that when vaccinated people were infected, they became only slightly ill, according to the publication Haaretz.
• As The Times’s Carl Zimmer wrote, “For now, there’s no evidence that Omicron causes more severe disease than previous variants.”

In the initial days after a new variant is discovered, I know that many people focus on worst-case scenarios. The alarming headlines can make it seem as if the pandemic may be about to start all over again, with vaccines powerless to stop the variant.

None of this changes what you can to do right now: Ventilate spaces. Use masks. Test if you have symptoms. Isolate if positive. Get vaccinated. Get boosted.

Government leaders can take an additional step, though: Improve global vaccine distribution. Variants are more likely to emerge in places with low vaccination rates, and less than 10 percent of people are vaccinated in many parts of Africa. (Look up the rate for any country.)

This weekend, Andy Slavitt, a former Covid adviser to President Biden, called for “the mass shipment of hundreds of millions of vaccines” to southern Africa.

To be clear, there is genuine uncertainty about Omicron. Maybe it will prove to be worse than the very early signs suggest and cause more severe illness than Delta. But assuming the worst about each worrisome new variant is not a science-based, rational response. And alarmism has its own costs, especially to mental health, notes Dr. Raghib Ali, an epidemiologist at the University of Cambridge.

“Of course we should take it seriously,” Ali wrote on Twitter, “but there is no plausible scenario that this variant is going to take us back to square one (i.e. the situation pre-vaccines).”

Absent new evidence, the rational assumption is that Covid is likely to remain overwhelmingly mild among the vaccinated (unless their health is already precarious). For most vaccinated people, Covid probably presents less risk than some everyday activities.

On “Meet the Press” yesterday, Dr. Anthony Fauci emphasized the continuing power of vaccination, even against variants. “It may not be as good in protecting against initial infection,” Fauci said, “but it has a very important impact on diminishing the likelihood that you’re going to get a severe outcome from it.”

Katelyn Jetelina, an epidemiologist, made a similar point in her Substack newsletter this weekend:

Do not take Omicron lightly, but don’t abandon hope either. Our immune systems are incredible.

None of this changes what you can to do right now: Ventilate spaces. Use masks. Test if you have symptoms. Isolate if positive. Get vaccinated. Get boosted.

Government leaders can take an additional step, though: Improve global vaccine distribution. Variants are more likely to emerge in places with low vaccination rates, and less than 10 percent of people are vaccinated in many parts of Africa. (Look up the rate for any country.)

This weekend, Andy Slavitt, a former Covid adviser to President Biden, called for “the mass shipment of hundreds of millions of vaccines” to southern Africa.

More on Omicron

• South Africa — one of the early places where Omicron was detected — has had enough Covid vaccines to inoculate much of the population. But only 35 percent of adults are fully vaccinated, partly because of mistrust in the medical system stemming from the AIDS epidemic, Zeynep Tufekci, a Times columnist, writes.
• Researchers are testing how the vaccines respond to the variant and could have results in a few weeks.
• Japan, Israel and Morocco have closed their borders to foreign travelers.

  coronavirus, COVID-19, vaccine