The latest Omicron subvariant may be a master at evading the immune response our bodies produce from the vaccine or previous COVID-19 infection, but a new study suggests existing booster shots will still help.
Getting a booster can generate enough of an antibody response and protection from severe disease outcomes to hold up against any of the new Omicron subvariants, according to an early release paper published this week in Science. That extends to BA.5, now the most prevalent COVID strain in the U.S. and a driver of COVID-19 reinfections across the country.
The finding comes as the Biden administration considers whether to expand access to a second booster shot to all adults because of concerns that subvariants BA.4 and BA.5 will further push up cases and hospitalizations. Since March, anyone 50 and older or immunocompromised and at least 12 years old has been eligible for a second booster, per CDC recommendations.
Led by the University of Washington School of Medicine’s Veesler Lab, the research team started a few months ago by just looking at the previously dominant BA.1, BA.2, and BA.2.12.1 subvariants, then later adding in BA.4 and BA.5. It assessed the properties of these subvariants and evaluated how a panel of seven vaccines already available in the U.S. and around the globe would protect against them.
BA.5 is a relatively new Omicron subvariant but “probably the most important one now in the study as it’s about to become globally dominant,” according to John Bowen, one of the paper’s lead authors and a biochemist at the Veesler Lab.
The BA.5 strain has been touted as the most contagious one yet, so much so that vaccinated people have reported catching it even after a recent bout of COVID-19. The first part of the study sheds light on why that is; BA.5 can outcompete other subvariants because its spike protein binds to the host receptor more than six times better than the original strain that first circulated in 2019.
The researchers ultimately determined that BA.5 will be the most immune-evasive COVID-19 variant to date, but that doesn’t mean our previous boosters can no longer restore protection.
“We were able to look at essentially every single prominent vaccine platform in the world side by side and see that despite the scariness of this variant, all of these vaccine platforms are going to elicit solid immune responses,” Bowen told Fortune.
Because of BA.5’s reputation, the findings initially caught the researcher by surprise.
“When I was seeing the data after the third shot, I had to repeat it over and over again because I was just like, ‘Why am I not seeing that this is as immune evasive as other people have said?’” Bowen recounted. “We were very excited to see that even though it’s more immune evasive than the other ones we tested, previous methods are still going to protect against it.”
The research effort was an international collaboration between infectious disease research physicians and scientists from UW Medicine, the Fred Hutchinson Cancer Center in Seattle, and institutes in California, Argentina, Italy, Pakistan, and Switzerland. It received funding from a plethora of sources, including the Bill & Melinda Gates Foundation and the National Institute of Allergy and Infectious Diseases.
The Food and Drug Administration has advised vaccine makers to update their booster shots to target the BA.4 and BA.5 Omicron subvariants. While people wait for those, though, Bowen said the research indicates that vaccines designed for a strain from a few years ago still work.
“We totally agree it’s very important to continue trying to find better ways to make protective vaccines,” he said. “It’s going to take some time to get those. If people need vaccines, we know that current boosting methods are going to be protective.”
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