A study report published in the New England Journal of Medicine has suggested that the new Omicron sub-variants of SARS-CoV-2 could significantly escape neutralising antibodies produced by earlier infection and immunity acquired from vaccination.
The researchers discovered that three Omicron subvariants BA.2.12.1, BA.4, and BA.5 are capable of escaping immunity offered by vaccines and previous infection.
Omicron variants evolving
Researchers state that this study provides an immunologic context for present outbreaks in populations with vaccine-acquired immunity and previous infection.
The research report suggested that the new subvariants continued to evolve after the highly infectious SARS-CoV-2 Omicron variant BA.1 — of COVID-19, which was discovered last year.
The researchers of Beth Israel Deaconess Medical Center (BIDMC) in Israel examined the antibody response to various SARS-CoV-2 Omicron subvariants in 27 people who had undergone vaccinations and booster shots. They also analysed a group of 27 people who had previously contracted COVID-19.
Countering antibody reactions to BA.4 and BA.5 were three times lower than those to the Omicron BA.1 and BA.2 variants.
"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," he added said.
The researchers also stated that newly devised variations may be more virulent.
Covid cases in India rising
Meanwhile, India reported 18,819 fresh Covid infections and 39 deaths in the last 24 hours.
As the number of fresh cases in the country skyrockets, several people believe that the fourth wave of the pandemic has begun in the nation.