NEW DELHI: A multi-centre study conducted by the Apollo Hospitals on a cohort of more than 31,000 vaccinated healthcare workers spanning across the country has found that COVID vaccines provided protection against infection in 95 per cent of the beneficiaries.
The study took place over four and a half months, from January 16 to May 30, and covered 31,621 healthcare workers who had received either both doses or the first dose of Covishield or Covaxin. Apollo Hospitals group said in a statement that the study of healthcare workers from 43 units of Apollo, spanning 24 cities in the country was to "evaluate the incidence of post-vaccination infections (PVIs)".
Dr Anupam Sibal, Group Medical Director and senior paediatric gastroenterologist, Apollo Hospitals Group said, "The results showed that COVID vaccines provided protection in more than 95 per cent of the recipients and that post-vaccination infection (PVI) occurred in only 4.28 per cent (1,355 out of 31,621) of the vaccinated healthcare workers."
The study included doctors, nurses, paramedical staff, as well as support and administrative staff. “The finding also showed that only 90 cases (0.28 per cent) required hospitalisation, with only three cases or 0.009 per cent requiring ICU admission,” he claimed.
Among the cohorts, Covishield was administered to 28,918 (91.45 per cent) healthcare workers, while 2,703 (8.55 per cent) received Covaxin. Also, 25,907 or 81.9 per cent of the healthcare workers were fully vaccinated, having received both doses of the vaccine, while 5,714 or 18.1 per cent had received only the first dose, the doctor said.
The incidence of PVI in those who had been administered Covishield was 4.32 per cent and in those who had received Covaxin was 3.85 per cent, according to Dr Raju Vaishya, one of the authors of the study. Sibal said that "out of the fully vaccinated workers, 1,061 or 4.09 per cent reported post-vaccination infections, while 294 or 5.14 per cent of the partly vaccinated workers tested positive".
The majority of infections occurred after two weeks of the last vaccination dose. "This study reiterates that our mainstay against COVID-19 is mass vaccination. Vaccines are not only safe, but they also help prevent severe manifestations of COVID-19 and will help save lives," said Dr Prathap C Reddy, Founder Chairman, Apollo Hospitals Group.
Most infections two weeks after getting last dose
The study was to "evaluate the incidence of post-vaccination infections. The finding showed that only 90 cases required hospitalisation. Of these, 48 were males and 42 were females with the majority i.e. 83 cases being below 50 years of age.
Of the three ICU admissions, two were males and one was a female, between the ages of 25-39, with two being fully vaccinated and one partially vaccinated. The majority of infections occurred after two weeks of the last vaccination dose. 43.6 per cent of infections occurred in HCWs below the age of 30, and 35.42 per cent in those in the 31-40 year age group.