Two new subvariants of omicron are now the dominant strains of the COVID-19 virus in the United States, but are they also more adept at evading prior immunity in the general population?
According to experts, the answer to that question may be yes. Both the BA.4 and BA.5 subvariants of omicron appear to be better at evading protections given both by COVID-19 vaccinations and boosters, as well as previous infection by the virus.
David Montefiori, a professor at Duke University Medical Center, told NBC News that in addition to being more contagious than the original omicron strain, the viruses are more able to evade preexisting protections.
He estimates that both the BA.4 and BA.5 variants of omicron are approximately three times less sensitive to neutralizing antibodies from existing COVID-19 vaccines than the original omicron variant.
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Some studies have also indicated that protection from previous COVID infections isn’t as effective at preventing illness from either of the new subvariants.
The good news is that it doesn’t appear that BA.4 or BA.5 is more likely to cause severe illness or death in vaccinated or boosted patients.
“There’s really no clear evidence that they’re more or less likely to make people sick and cause severe illness and death,” he said.
According to the CDC, omicron infections tend to be less severe, but can still result in hospitalization and death, especially since a more-transmissible version of the virus could mean additional strain on hospitals.
Federal officials have asked vaccine manufacturers to tailor new booster shots to combat the BA.4 and BA.5 variants, with some experts believing that boosters could be recommended for most Americans by the fall.