New Delhi: A multi-centre study on a cohort of over 31,000 vaccinated healthcare workers of a leading private healthcare firm, spanning across the country, has found that COVID-19 vaccines provided protection against infection in 95% of the beneficiaries, hospital authorities claimed on Wednesday.
The study by Apollo Hospitals 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, a hospital spokesperson said.
The study of healthcare workers from 43 units of the healthcare giant, spanning 24 cities in the country was to “evaluate the incidence of post-vaccination infections (PVIs),” the Apollo Hospitals group said in a statement.
Dr Anupam Sibal, group medical director and senior pediatric gastroenterologist, Apollo Hospitals Group said, “The results showed that COVID vaccines provided protection in more than 95% of the recipients and that post-vaccination infection (PVI) occurred in only 4.28% (1,355 out of 31,621) of the vaccinated healthcare workers.”
“The finding also showed that only 90 cases or 0.28% of them required hospitalisation, with only three cases or 0.009% requiring ICU admission,” he claimed.
The most important finding of the study was that there were “no deaths in case of COVID-19 infection after vaccination,” he was quoted as saying in a statement issued by the hospital.
Among the cohorts, Covishield was administered to 28,918 healthcare workers (91.45%), while 2,703 (8.55%) received Covaxin. Also, 25,907 or 81.9% of the assessed healthcare workers were fully vaccinated, having received both doses of the vaccine, while 5,714 or 18.1% had received only the first dose, the group said.
The incidence of PVI in those who had been administered Covishield was 4.32% and in those who had received Covaxin was 3.85%, according to Dr Raju Vaishya, one of the authors of the study.
The healthcare workers (HCWs) who took part in the study included doctors, nurses, paramedical staff, as well as support and administrative staff, among others, the hospital spokesperson said.
The findings of the study are under consideration for publication in a peer-reviewed medical journal, the statement said.
Sibal said that “out of the fully vaccinated workers, 1,061 or 4.09% reported post-vaccination infections, while 294 or 5.14% of the partly vaccinated workers tested positive”.
Commenting on the study, Dr Prathap C. Reddy, founder-chairman, Apollo Hospitals Group said, “This study reiterates the fact 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.”
While the study emphasises the fact that COVID-19 vaccines are effective, it reiterates the importance of continuing to adhere to COVID-19-appropriate behaviours, even when fully vaccinated.
A range of adverse events following immunisation (AEFIs) were also recorded in several recipients of Covieshield or Covaxin, the study says.
“This study period covered the second wave and the maximum infections occurred in April and May. Despite the high infection rate in the community during this period, the vaccinated HCWs were protected,” he said.
Meanwhile, the Fortis Healthcare group in a statement late on Wednesday night revealed details of its own study on vaccinated healthcare workers in the January-May period, also spanning multiple facilities.
“About 99% of HCWs who received both first and second doses of the vaccine did not face severe outcomes, as in ICU care or mortality. Also, after receiving both the doses, only 6% of the staff got infected,” the Fortis group claimed in the statement.
It further said that among those who got infected after getting fully vaccinated, 92% were mildly-infected cases while 7% had developed moderate illness requiring oxygen support, and only 1% developed severe illness requiring ICU care or ventilation.
While the healthcare group did not share the exact number of people who took part in the study, it said that till recently, “over 20,000 (direct and indirect) Fortis employees had taken the first dose and more than 16,000 had taken both doses of COVID-19 vaccine”.