Is BA.5 more dangerous? Everything you need to know about the new omicron subvariant
A particularly contagious omicron subvariant is on track to become the dominant coronavirus strain in North Carolina.
In the Southeast, BA.5 comprises more than half of total COVID-19 cases, according to data from the Centers for Disease Control and Prevention. The spread of BA.5 has caused a surge in cases across the country and, so far, a slight uptick in N.C.
Scientists are scrambling to learn what that could mean for vaccine efficacy, public health precautions and hospitalizations. Here’s what they know so far:
Is BA.5 more contagious?
BA.5 is undoubtedly more contagious than the variants that dominated earlier this summer — one study estimated it is 1.4 times more transmissible than the subvariant that dominated before it.
Its transmissibility is evidenced by BA.5’s rapid takeover as the dominant coronavirus strain. In North Carolina, it went from accounting for 1% of cases in early May to 38% of cases at the end of June.
What if I just had COVID?
A recent COVID-19 infection might not be enough to protect you against a new infection from BA.5.
Earlier in the pandemic, scientists operated under the rule of thumb that infections offered you three months of protection against COVID-19. BA.5 has changed that calculus.
Thanks to spike protein mutations, this subvariant is particularly adept at evading immunity from both vaccinations and past infections, even if the infection was recent.
Dr. David Montefiori, coronavirus vaccine researcher at the Duke University School of Medicine, said getting boosted is one of the most important things you can do to protect yourself. The initial series of shots (two Moderna/Pfizer doses or one J&J dose) offers very little protection against omicron variants, Montefiori said.
His lab has found that boosters improve immunity against omicron 20-fold.
Everyone 5 and older are eligible to get one booster and people older than 50, or who are severely immunocompromised, are eligible for a second booster.
How dangerous is it?
No evidence has shown that BA.5 will cause more severe illness than previous omicron subvariants.
Montefiori said it’s helpful to think of the immune system as having two lines of defense. The first line protects the body from contracting COVID-19 while the second line stops the virus from causing serious illness once infected.
The first line of defense has been seriously weakened by BA.5. By some measures, it’s three times weaker against this subvariant than the initial omicron strain.
That second line of defense, which stops the virus from causing serious illness, hasn’t wavered much. Hospitalizations and deaths do not appear to have ticked up in response to rising cases.
It’s still not clear how this subvariant could affect your chances of developing long COVID.
What are the symptoms of BA.5?
BA.5 symptoms appear to closely mirror those of its omicron relatives.
Mark Heise, an immunologist at UNC- Chapel Hill, said infected patients often report sore throats, muscle aches and upper respiratory symptoms. Generally, omicron doesn’t appear to affect taste or smell as much as earlier variants.
Do I need to wear a mask?
If you stopped wearing face masks in public, it might be time to put them back on.
Well-fitting, high quality masks are still effective at protecting against BA.5. Montefiori recommends N95 or KN95 masks, though surgical masks are better than nothing at all.
Heise said there isn’t any concrete data to suggest that people should be wearing masks outdoors.
“Provided that I’m not really crowded in, I’m still not masking when I’m just talking with people outside,” he said. “But that doesn’t mean it couldn’t change.”
Teddy Rosenbluth covers science for The News & Observer in a position funded by Duke Health and the Burroughs Wellcome Fund. The N&O maintains full editorial control of the work
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