Two doses of vaccine give 95% protection against Covid death: ICMR study
Two doses of Coronavirus disease (Covid-19) vaccines provide as high as 95% protection against deaths due to Covid-19, and a single dose is 82% effective in preventing deaths, shows the latest study from the Indian Council of Medical Research (ICMR).
The study that has been published in the Indian Journal of Medical Research (IJMR) was conducted among 117,524 police personnel from the Tamil Nadu police department who either received no shot or at least one Covid-19 vaccine shot.
“In conclusion, our analysis indicated Covid-19 vaccination, even with single dose, was effective in preventing deaths. It is necessary to increase coverage of Covid-19 vaccines, regardless of the type of vaccines, to reduce mortality in current as well as future waves of Covid-19 epidemic,” said researchers in the study paper.
Tamil Nadu Police department has been documenting vaccination of its members, and Covid-19 deaths during the second wave along with details of the date of hospitalization and vaccination.
The data was used to estimate the incidence of deaths due to Covid-19 among vaccinated and unvaccinated police personnel for the study. The incidence of mortality among vaccinated and unvaccinated individuals was compared to calculate the relative risk of mortality associated with Covid-19 vaccination, according to the study.
There are 117,524 police personnel working with department of police in Tamil Nadu. Between February 1 and May 14 this year, 32,792 received one dose, 67,673 received two doses while 17,059 did not receive any Covid-19 vaccine doses.
The study finds that 31 Covid-19 deaths were reported among these police personnel between April 13 and May 14, of which four had taken two doses of the vaccine, seven had taken one dose and the rest 20 were unvaccinated.
The incidence of Covid-19 deaths among the vaccinated with zero, one and two doses was 1.17, 0.21 and 0.06 per 1,000 police personnel respectively.
Compared to unvaccinated individuals, the relative risk of death due to Covid-19 among those receiving one and two doses was 0.18 and 0.05 respectively. The vaccine effectiveness in preventing deaths with one and two doses was 82% and 95% respectively.
The Centre also released data of a similar study done by PGI Chandigarh on protection that vaccines have provided in vaccinated police personnel in Punjab.
“It was a simple study that showed in 4,868 police personnel when no vaccine dose was given, 15 deaths took place, and incidence was three per 1,000. In 35,856 police personnel, who took one dose of the Covid-19 vaccine, there were nine deaths, and incidence was 0.25 per 1,000. About 42,720 police personnel who took two vaccine doses, two deaths happened and the incidence was 0.05 per 1000,”said VK Paul, member (health), Niti Aayog, during the health ministry briefing on Covid updates on July 2.
“Vaccine protection from death due to Covid-19, when we do the math, comes to about 92% after one dose, and 98% in those who took two doses. Therefore, it is clearly shown that progression to severe disease is reduced, and serious disease gets almost eliminated and risk of death is also significantly,” he added.