If you've received a new omicron-specific Covid booster, you're the most protected you possibly can be against the virus.
But there's a new batch of so-called "Scrabble" variants circulating globally. While omicron's BA.5 subvariant still accounts for nearly 40% of U.S. Covid cases, strains like BQ.1, BQ.1.1 and BA.4.6 are rising each week, according to the latest Centers for Disease Control and Prevention data.
The new strains present an uncomfortable question: Are the new bivalent boosters still worth getting, or has the virus already outmaneuvered them?
"A booster is a booster," Dr. Roy Gulick, chief of the division of infectious disease at Weill Cornell Medicine and New York-Presbyterian Hospital, tells CNBC Make It. "What about all these new Scrabble variants? The message remains the same: Get boosted, provoke your immune system to make a good response to the virus."
The emerging strains are new enough that booster-shot-protection data doesn't yet exist for them. But experts still expect the shots to ramp up your immunity against all Covid variants, to some degree.
Here's why, and what else you need to know.
The new variants are descendants of omicron, which is a promising initial sign for the boosters.
"We have some hope, especially since this is all the same omicron. They're just multiple subvariants," says Dr. Rachael Lee, an associate professor in the division of infectious diseases at the University of Alabama at Birmingham. "I'm hoping that that is enough to protect us through fall."
Even though the Scrabble variants have found new ways to "cut through our immunity," they likely can't evade vaccine-induced protection entirely, says Dr. Deborah Fuller, a University of Washington School of Medicine microbiologist.
When you get vaccinated, your body generates an alphabet soup of different virus-fighting antibodies, she explains. Some antibodies eventually become more dominant than others, and provide the majority of your body's protection.
Those dominant antibodies become the target of new Covid mutations. But the omicron-specific boosters — or any Covid booster, for that matter — can help expand your "soup" and generate a greater concentration of antibodies, Fuller says.
That can "restore a level of immunity and patch up the holes that some of these new Scrabble variants have found," she explains.
No vaccine is ever 100% effective against infection. But ramping up other antibodies could help control the virus's ability to replicate, helping shorten the length of infections and protect against severe disease and hospitalization, Fuller says.
Without data on the new boosters' efficiency against the Scrabble variants, some experts are looking at how the original monovalent Covid booster — which became available to U.S. adults ages 18 and older in November 2021 — performed against then-emerging variants like omicron.
"There are studies already to show that even the monovalent booster, whether it was Pfizer or Moderna, actually produces similar neutralizing antibodies against these variants [when compared to other variants]," says Dr. Jose Vazquez, chief of infectious disease at the Medical College of Georgia at Augusta University.
Recent data has shown that some antibodies, whether from vaccination or previous infection, have lasted as long as a year and a half in some people — and more than 80% of the North American population has had a Covid vaccine or infection, says Vazquez.
"Fortunately for us, all of these vaccines, including the original vaccine, will elicit some type of neutralizing antibody response," Vazquez says. "That will help us despite the fact that these are brand-new variants that we have."
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