Certain high-risk behavioural factors such as binge drinking, smoking and strenuous physical activity were found to be positively associated with unexplained sudden death.

COVID-19 vaccination did not increase the risk of unexplained sudden death among young adults in India, states the latest Indian Council of Medical Research (ICMR) study. On the contrary, the study finds that COVID-19 vaccination reduced the risk of unexplained sudden death in this age group. The peer-reviewed findings were published recently in the Indian Journal of Medical Research.

The study titled “Factors associated with unexplained sudden deaths among adults aged 18-45 years in India – A multicentric matched case–control study” was carried out to find out the impact of the vaccine on cardiac health and sudden death in young Indians. It was conducted in 47 tertiary care hospitals across India, with 729 people who had died unexpectedly after contracting COVID-19 and 2,916 controls in the analysis. The COVID-19 death cases included healthy individuals aged 18-45 years without any known co-morbidity, who suddenly died of unexplained causes between October 1, 2021, and March 31, 2023.

A majority of the participants had been vaccinated once. About two per cent of cases and one per cent of controls were hospitalised for COVID-19 and two per cent of cases and one per cent of controls had a history of post-COVID-19 condition (PCC) a month after COVID-19 diagnosis.

Certain high-risk behavioural factors such as binge drinking, smoking and strenuous physical activity were found to be positively associated with unexplained sudden death among young adults in India. 

Here are some of the key findings of the study:

1. “We found no evidence of a positive association of COVID-19 vaccination with unexplained sudden death among young adults. On the contrary, the present study documents that COVID-19 vaccination indeed reduced the risk of unexplained sudden death in this age group. In terms of assessing the given association between vaccine and unexplained sudden death, we ruled out the role of chance through a statistically significant matched OR and adjusted for known confounders.”
2. “Our findings did not indicate any evidence of positive association of unexplained sudden death with COVID-19 vaccination. However, a history of sudden death in the family, COVID-19 hospitalisation and certain high-risk behavioural factors were positively associated with unexplained sudden death among young Indians.”
3. “The reduced risk following COVID-19 vaccination, as observed in our study, could possibly be due to the protection offered by COVID-19 vaccination against severe COVID-19, leading to reduced chances of cardiovascular events and thereby reducing the risk of death among them.”
4. “We identified two lifestyle related high-risk behaviours associated with unexplained sudden death. Binge drinking 48 hours before death/interview was identified to be associated. Several studies have documented that heavy and binge drinkers are at increased risk of stroke, cardiac arrhythmias and sudden cardiac death. It has been shown that large amount of alcohol can lead to QT prolongation and cardiac arrhythmias, in turn leading to sudden death.”