Omicron generated antibodies effective against all variants of concern: ICMR study

New Delhi, Jan 26: The latest study conducted by Indian Council of Medical Research (ICMR) shows that antibodies generated by Omicron variant of COVID-19 are not only effective against it but also other variants of concern (VOCs) including Delta. "The individuals infected with Omicron have significant immune response which could neutralize not only the Omicron but also the other VOCs including most prevalent Delta variant," a study by ICMR  has revealed. "This suggests that the immune response induced by the Omicron could effectively neutralize the Delta variant making the re-infection with Delta less likely, thereby displacing the Delta as dominant strain. This emphasizes the need for the Omicron specific vaccine strategy," it further said. In this study, the ICMR  has analyzed the IgG and neutralizing antibodies (NAbs) against B.1, Alpha, Beta, Delta and Omicron variants with the sera of individuals infected with the Omicron variant (B.1.1529 and BA.1) as currently India is facing the third wave of the COVID-19  pandemic. ICMR has said that within short span of time, the variant has shown high transmissibility and capability of evading the immune response generated against natural infection and vaccination. The immune escape potential of Omicron is a serious concern and further needs to be explored. The study, where antibodies response was assessed in those who are infected by Omicron, is pre-print not peer reviewed. It also stated: "In the present study, we have assessed the IgG and neutralizing antibody (NAb) response in breakthrough individuals vaccinated with two doses ChAdOx1 nCoV-19 vaccine (n=25), breakthrough individuals vaccinated with two doses of BNT162b2 mRNA vaccine (n=8) and unvaccinated individuals (n=6). All these individuals were infected with Omicron variant." The participants in the study were adults from foreign countries and adolescents from India.