Infections of Covid-19 that were contracted during earlier waves will provide little to no protection against the current subvariant, BA.5, dominating US cases, Dr Anthony Fauci said.
“Omicron as a broad category has been particularly problematic,” the director of the National Institute of Allergy and Infectious Diseases said Tuesday during a White House briefing on the spread of a variant that now accounts for more than 60 per cent of cases in the country.
“Each successive variant has a bit of a transmission advantage over the prior one,” Dr Fauci said, adding that if you were a person who contracted the virus during the first or even second waves, you “really don’t have a lot of good protection” in this current wave.
Health experts from across the globe have been warning in recent weeks of the new Omicron subvariant, labelling it a “stealthy” strain for its capability to reinfect people within weeks of contracting the virus.
“What we are seeing is an increasing number of people who have been infected with BA.2 and then becoming infected after four weeks,” said Andrew Roberston, the chief health officer in Western Australia, during an interview with News.com.au.
The Australian infectious disease expert’s remarks were echoed by Dr Fauci during Tuesday’s address, who warned that new variants will continue to pose a threat to society so long as the virus continues to spread unchecked.
“Variants will continue to emerge if the virus circulates globally and in this county. We should not let it disrupt our lives, but we cannot deny that it is a reality that we need to deal with,” he said.
Part of what’s driving the new subvariant’s ability to infect people at a more virulent rate than previous iterations of Omicron, the director of the Centers for Disease Control and Prevention said, was because it “substantially evades” the antibodies from both vaccination and prior infection.
“People with prior infection, even with BA.1 or BA.2, are likely still at risk for BA.4 or BA.5,” CDC Director Rochelle Walensky added during the briefing.
Despite the seemingly dire warnings about this most recent subvariant, both Dr Fauci and health experts across the country seem to believe that vaccinations and boosters will provide partial immunity and can still significantly protect against potentially more severe infections and help keep the risk of hospitalisation at bay.
“Our data suggest that these new Omicron subvariants will likely be able to lead to surges of infections in populations with high levels of vaccine immunity as well as natural BA.1 and BA.2 immunity," said Dr Dan Barouch, an author on a paper, published with the New England Journal of Medicine, which found that there was a three-fold reduction of neutralising antibodies from vaccines and infection against BA.4 and BA.5, which was substantially lower than BA.1 and BA.2.
“It is likely that vaccine immunity will still provide substantial protection against severe disease with BA.4 and BA.5,” Dr Barouch said to CNN.
Cases across the US have continued to hover at around 100,000 daily, but most health experts agree that this is a grossly underreported figure as most people testing positive these days are relying on at-home tests and many states have dropped or significantly reduced the number of facilities offering public testing.
Hospitalisations, according to The New York Times, have shot up by 18 per cent over the past two weeks in the US.
