The most recent omicron subvariants have caused new infection spikes across the United States, as researchers find they are better at eluding vaccines
The latest omicron subvariants, which include the BA.4 and BA.5 forms, have been found to render vaccines and most antibody treatments ineffective as they can surpass them easier than previously thought.
Researchers at Columbia University Vagelos College of Physicians and Surgeons found that the subvariants BA.2.12.1, BA.4, and BA.5 are rapidly expanding worldwide, which these subvariants are thought to be even more transmissible than prior omicron subvariants, owing to several new mutations in spike proteins.
BA.4/5 now makes up over 50% of new COVID cases in the United States
the researchers studied the ability of antibodies in laboratory experiments from individuals who received at least three doses of an mRNA vaccine, or had two shots and were then infected with omicron – to neutralise the new subvariants.
The team, however, didn’t look at individuals who had not received a booster shot, because a previous study found that two doses provide little protection against infection by earlier omicron variants.
“As these highly transmissible subvariants continue to expand around the globe, they will lead to more breakthrough infections in people who are vaccinated and boosted with currently available mRNA vaccines.”
Overall, the study highlighted that while BA.2.12.1 is only modestly more resistant than BA.2 in individuals who were vaccinated and boosted, BA.4/5 was at least four times more resistant than its predecessor.
David D. Ho, MD, director of the Aaron Diamond AIDS Research Center, said: “The virus is continuing to evolve, as expected, and it is not surprising that these new, more transmissible subvariants are becoming more dominant around the world.
“Understanding how currently available vaccines and antibody treatments stand up to the new subvariants is critical to developing strategies to prevent severe disease, hospitalizations, and deaths—if not infection.”
BA.4/5 was at least four times more resistant than other omicron subvariants
The researchers additionally tested the ability of 19 monoclonal antibody treatments to neutralise the variants and found that only one of the available antibody treatments remained highly effective against both BA.2.12.1 and BA.4/5.
Ho added: “Our study suggests that as these highly transmissible subvariants continue to expand around the globe, they will lead to more breakthrough infections in people who are vaccinated and boosted with currently available mRNA vaccines.
“Efforts in the United States to develop new vaccine boosters aimed at BA.4/5 may improve protection against infection and severe disease.
“In the current environment, though, we may need to look toward developing new vaccines and treatments that can anticipate the ongoing evolution of the SARS-CoV-2 virus.”
Even though research demonstrates how new variants may cause more infections in vaccinated individuals, the vaccines continue to provide the best protection against severe disease and should still be taken to prevent serious infection and death.
