As the Bay Area’s latest COVID surge threatens to be the biggest yet and the coronavirus continues to spin off new, immune-evasive variants, are repeated infections a part of living with COVID?
Increasingly, experts fear, the answer is yes.
While doctors agree it’s unlikely people will get infected twice with the same variant, it’s probable over the long term that new COVID variants could infect people again due to the lightning-speed evolution of the novel coronavirus.
“I would not be surprised if we see people get infected more than once per year,” Dr. Anthony Fauci, President Joe Biden’s chief medical adviser, told NBC News.
Hybrid immunity — the dual protection afforded by infection plus vaccination — seems to be less protective than it used to be against getting COVID again, although vaccines continue to stave off serious illness. But with many people now having had both omicron and a later subvariant such as BA.2, BA.4 or BA.5, studies show that vaccination coupled with previous exposure still prevents reinfection better than a vaccine or infection alone.
“Your prior immunity, including from infection, is not worth nothing, it’s just worth less than previously,” said Dr. Bob Wachter, the chair of UCSF’s Department of Medicine, on a recent episode of the Chronicle’s Fifth and Mission podcast.
Dr. Monica Gandhi, an infectious disease specialist at UCSF, noted that hybrid immunity is especially useful in preventing severe outcomes.
While “SARS-CoV-2 is not an eradicable virus per its properties,” she said, increasing global levels of immunity through vaccination, infection or both mean that deaths remain low.
Dr. Abraar Karan, an infectious disease doctor at Stanford, added that reinfections strengthen cellular immunity — the way the body deeply remembers how to fight the virus, which people get either through a vaccine or their first infection. This means reinfections should be milder and milder.
But it also depends on what “unpredictable” new variants bring, he noted, as the virus could evolve to become more severe.
With disease containment measures such as improved ventilation and nasal vaccines — which can produce mucosal immunity that’s better at preventing infection than current vaccines — future COVID outbreaks could be more localized, Karan said. That could limit their ability to spread quickly around the world, which has been one of the biggest problems over the past few years in combatting the pandemic.
“It could be that we slow down spread enough that outbreaks are smaller and occur less frequently,” he said. In other words, “not every outbreak is a pandemic.”
He added that slowing the spread of COVID will also help slow the development of new variants, though they will continue to pop up.
But COVID remains a relatively new disease, and scientists and experts still don’t know what effect repeated reinfections have on the body, or what it means for long COVID.
“I think there’s a lot about this that we don’t know, but my bottom line is that reinfection is not nothing,” Wachter said. “Unfortunately I think if you get reinfected, we have to assume that that has potential consequences.”