Along with BA.4, BA.5 is considered to have the ability to spread quickly, soon to dominate many regions of the world.
According to new data from the Beth Israel Deaconess Medical Center, Harvard Medical School (USA), the Omicron sub-variants BA.4 and BA.5 appear to escape antibodies in both people who have been infected with Covid-19 and group that received the booster vaccine.
However, a Covid-19 vaccine is still expected to provide significant protection against severe illness. In addition, vaccine manufacturers are working on an updated shot that can induce a stronger immune response against the variants.
According to the study published in the New England Journal of Medicine, the level of neutralizing antibodies from vaccines and previous infections with Covid-19 against variants BA.4 and BA.5 is several times lower than that of the SARS virus- The original CoV-2.
Dan Barouch, author of the paper, is director of the Center for Virus and Vaccine Research at Beth Israel Deaconess Medical Center.
“We noted that the neutralizing antibody titers from vaccination and Covid-19 infection with BA.4 and BA.5 decreased by 3 times compared to BA.1 and BA.2, which were already significantly lower than previous variants,” writes Dr. Barouch.
“However, vaccine-induced immunity may still provide significant protection against severe disease with BA.4 and BA.5 infections.”
This finding is similar to the study by scientists at Columbia University.
They found that the BA.4 and BA.5 viruses were more likely to escape the antibodies in the blood of fully vaccinated and boosted adults than the other Omicron subvariant, increasing the risk of Covid-19 infection.
The US Centers for Disease Control and Prevention (CDC) estimates that 94.7% of the US population 16 years of age and older have antibodies against the SARS-CoV-2 virus through vaccination, infection, or both.
It is estimated that BA.4 and BA.5 caused about 35% of new Covid-19 infections in the US in the week of June 3, compared with 29% the week before.
So far, BA.4 and BA.5 are the fastest spreading SARS-CoV-2 variants, which are expected to dominate in the US and Europe in the next few weeks.