India’s top medical research body has not found evidence linking Covid-19 vaccination as the cause of “unexplained sudden deaths”, but the study by the Indian Council of Medical Research (ICMR) instead points out the disease, binge drinking and intense exercise as probable causes.

The ICMR study underlined that history of sudden death in the family, Covid-related hospitalization, and certain high-risk behavioural factors “were positively associated with unexplained sudden death among young Indians”.

Sudden death

In the peer-reviewed study published earlier this year, ICMR said its findings “did not indicate any evidence of positive association of unexplained sudden death with Covid-19 vaccination”.

The study took place following media reports, which were also called “anecdotal reports”, of unexplained death among people in the age group of 18–45 years, and among “apparently healthy individuals”, between October 2021 and March 2023.

The study has been published in the Indian Journal of Medical Research and included participation of 47 tertiary care hospitals country-wide.

“Family history of sudden death, behaviours such as binge drinking 48 hrs before death and vigorous-intensity physical activity performed 48 hrs before death significantly increased the odds for unexplained sudden death among young adults,” it said.

Research paper

The research paper mentioned that ICMR listed 29,171 sudden deaths among individuals aged 18-45 years as potential cases and 729 of them, which include 2916 ‘control’ subjects were scrutinised. Participants did not have any known co-morbidity.

Majority of participants (87 per cent) had received at least one dose of Covid-19 vaccination any time before the outcome. Some 2 per cent, had been hospitalised (for Covid) among which another 2 per cent had a history of post-Covid conditions (PCC) at one month after diagnosis (none reported at three months). Some 10 per cent had a family history of sudden death; about 27 per cent of cases were smokers. Alcohol use was reported among 27 per cent of cases. Among these, almost seven per cent of the cases reported binge drinking 48 hrs before death or interview. Vigorous intensity physical activity in the past one year was reported by 18 per cent of cases.

According to Dr Naresh Trehan, Chairman and Managing Director, Medanta Heart Institute (and one of India’s foremost cardiovascular and cardiothoracic surgeons), the studies prove that India-made vaccines did not accentuate risk of sudden deaths among young adults. Medanta is listed on the bourses as Global Health Ltd.

“On the contrary, the present study documents that Covid vaccination, especially the India-made ones indeed reduced the risk of unexplained sudden death in this age group. In fact, the study suggests that there was a reduced risk of cardio-vascular events and deaths because of severe Covid-19 incase vaccination was done,” he told businessline.

Trehan said the study shows that two doses of the vaccine lowered the odds of unexplained sudden death, but a single dose did not.

“Factors, such as use of alcohol and tobacco, family history of sudden cardiac arrests and unaccustomed vigorous physical activity are the biggest culprits behind the number of unexplained deaths, and this is something that we have been pointing out too across our literature,” he said, adding that risks are aggravated in case of those who are at threat of severe infection, or cardiovascular causes like arrhytmia, myocarditis, etc.