Hybrid immunity is effective in preventing the spread of the Omicron, a variant of coronavirus, according to the findings of the study conducted by a team led by a Kerala doctor. 

"The impact caused by Omicron in India was less compared to the crisis created in countries such as the US and the UK. Hybrid immunity present in Indian population is one of the main reasons for low death rate compared to other countries," said clinical immunologist and rheumatologist Dr Padmanabha Shenoy who headed the research. Dr Sakir Ahmed of Kalinga Institute of Medical Sciences, Bhubaneswar, was co-researcher.

"Human body gains immunity through natural infection or vaccination. Hybrid immunity is the immunity generated when a person with prior infection receives a vaccine," Dr Shenoy told reporters here. The research included about 2,000 patients with autoimmune rheumatic diseases at the Centre for Arthritis & Rheumatism Excellence (CARE). It was found during the initial studies that hybrid immunity generated antibody levels 30 times higher than those who have received two doses of vaccines.

While 60 per cent of patients who had received two vaccine doses were able to neutralise the original Wuhan strain of virus, 90 per cent of people with hybrid immunity could neutralise the original strain. Even in the Delta variant also, the figures were almost similar.

The research data was published in Lancet Rheumatology in November. But when it comes to the Omicron variant, patients who had received two doses of vaccines either Covaxin or Covishield were not able to neutralise the Omicron variant.

"However, 65 per cent of patients, who had received a single dose of Covishield following an infection, were able to neutralise Omicron. As more than 70 per cent of Indians were infected with Delta during the second wave and India has vaccinated 95 per cent of the eligible population, at least with one dose close to three-fourths of India's population has hybrid immunity. This hybrid immunity wall is the reason India had a relatively minor third wave," Dr Shenoy said. He said his team is now involved in decoding the impact of the Covaxin Hybrid in preventing the Omicron, and it would be made known soon.