NIV to isolate, culture Omicron strain to assess vaccine efficacy, Health News, ET HealthWorld
The scientific exercise will answer two critical questions: Can this variant impact the efficacy of Covishield and Covaxin; and will it outfight existing antibodies in those who have had Covid illness from old strains?
“The ICMR-NIV received the positive sample of the Dombivali man whose genome sequencing confirmed the infection from Omicron strain on Saturday night. Isolating the whole Omicron strain from the sample is going to take at least a week. Thereafter we will be able to take up a neutralization study to assess the efficacy of Covaxin- and Covishield-induced antibodies and natural infection-induced antibodies against the lab-grown strain,” said an ICMR official.
The isolation and culturing of the Omicron strain are going to be the first step towards finding answers to these crucial questions. “Once we have isolated the whole strain and grown a sufficient amount of it in our bio-safety lab, our scientists will be able to take up the neutralization study to assess vaccine efficacy,” the official said.
A neutralization study is the best way to assess vaccine efficacy and chances of reinfection. Through this study, scientists will also be in a position to compare the ‘level’ of neutralizing ability against existing strains and the new variant.
“And beyond cell-culture experiments, the protective ability of vaccine-induced as well as natural infection-induced antibodies can be studied in animal models against the new variant. A positive correlation will increase the confidence in vaccines,” said another virologist.
Infection by any strain of SARS-CoV-2 kicks off an immune response against the entire virus, and not just against certain parts such as its ‘spikes’. This is why many experts believe mutations are unlikely to affect vaccine-induced protection.
There are 1,273 amino acids on the SARS-CoV-2’s spike protein that triggers the immune response. The new Omicron variant has 32 amino acid changes or mutations in the S protein. So, the assumption that vaccines will offer protection against the new strain sounds logical, experts said. The Neutralization Study
Scientists at ICMR-NIV will be isolating and culturing (growing) the Omicron strain in ample amounts using animal cells Once through, they will draw neutralizing antibodies from the serum or blood of Covid-recovered patients/ vaccinated humans
The lab-cultured (grown) Omicron strain will be used in the neutralization study by subjecting the strain to antibodies drawn from the recovered patients/vaccinated participants and examining how they react with each other.