New COVID-19 variants are coming. Will there be a winter surge?

As the weather cools and the San Francisco Bay Area enters its traditional cold and flu season, residents are starting to wonder: Will the fall and winter bring another COVID-19 surge, too?

SFGATE asked two UCSF experts whether we're likely to see a repeat of last year, when the highly transmissible omicron variant caused cases to shoot up dramatically. Both agreed that infections will increase as the days get colder, driving people indoors, where the airborne virus spreads more easily. Both also maintained, though, that while a small number of people will become very sick, or even develop long COVID, the majority of people who catch the virus will experience mild illness.

"We are in a completely different time because we have so many more tools to help even unvaccinated people stay out of the hospital, and the population has already seen so many waves of COVID," Dr. Peter Chin-Hong, a UCSF infectious disease specialist, wrote in an email. "That means we won't see as many hospitalizations and deaths as in the past two winters."

Chin-Hong said that, because the majority of the population has either vaccine- or infection-induced immunity, he's stopped using the word "surge" to describe rising infections. Instead, he prefers "increase in cases."

"'Surge' has become a fighting word for some people as it gives them PTSD from 2020 and 2021," he wrote.

COVID is here to stay, according to infectious diseases expert Dr. Monica Gandhi. That means we should get used to seeing cases go up every winter from now on.

"[W]ith vaccines, boosters, and antivirals for older people, the Bay Area at some point will have to decide how to live with [COVID]," Gandhi wrote in an email, pointing out that it is now carried by 29 species of animals, as well as being thoroughly entrenched in humans. "It does not have the features of an eradicable virus."

Which variant will be dominant this winter?

The vast majority of infections in the Bay Area are still being caused by variants in the omicron family, as they have been for several months. In mid-October, the BA.5 variant remained dominant, accounting for 71% of cases in the US, while closely related variants BA.4 and BA.4.6 are causing about 13% between them, according to the Centers for Disease Control and Prevention. The newly updated booster shot, which contains genetic information from both omicron and ancestral strains of the virus, is expected to provide significant protection against all three of those commonly circulating variants.

Chin-Hong said experts are watching at least four other descendants of the original omicron variant. One, called BF.7, is now the third most common strain in the U.S.

"If any variant has a chance of giving BA.5 a run for the money, it is BF.7," Chin-Hong said. "It is already causing more than 25% of cases in Belgium."

BQ.1 and BQ1.1, both immune evasive variants, are rising rapidly and account for about about 11% of cases in the US.

Even if another variant begins circulating widely, though, "people who are up-to-date on vaccines will avert serious disease, hospitalization and death for many more months if not more than a year without further boosters," Chin-Hong said.

Are any of these variants especially scary?

It's true that several variants have become adept at evading antibodies, the body's first line of defense against infection; antibody production also wanes over time. However, thanks to both widespread vaccinations and massive waves of infections over the last two and a half years, the vast majority of the U.S. population has some immunity to the virus.

When antibody protection fades, you become more likely to actually catch the virus. However, your body produces several types of specialized cells in response to either infection or vaccines, which remember how to fight COVID once it's entered your body. This "cellular immunity" is extremely long-lasting and harder for new variants to evade, according to Gandhi. In 2020, scientists found that people previously infected by SARS, which is in the same family as COVID, still had cells that could recognize and fight infection 17 years later.