COVID-19. Since the initial highly infectious SARS-CoV-2 Omicron variant -- known as BA.1 -- of COVID-19 emerged in 2021, its new sub-variants continue to evolve.
The three Omicron subvariants BA.2.12.1, BA.4, and BA.5 were discovered to significantly evade neutralising antibodies produced by both vaccination and prior infection.
Neutralizing antibody responses to BA.4 and BA.5 were three times lower than those to the Omicron BA.1 and BA.2 variants and were roughly 20 times lower than those to the original WA1/2020 strain. "Our findings suggest that the Omicron variants have continued to evolve," said study senior author Dan H Barouch, director of the Center for Vaccine and Virology Research at BIDMC. "This has important public health implications and provides the immunologic context for current surges among populations with high rates of vaccinations and previous infection," Barouch said.
The researchers stated that newly developed variations may be more contagious and may overcome the immune defences from earlier infections or vaccinations more successfully.