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Explained: Sudden deaths due to Covid vaccine? Here’s what medical evidence cited by govt actually says
Govt on Wednesday cited studies by top Indian experts to say there is no link between sudden deaths and Covid vaccination.
Amid recent cases and viral videos of young people suddenly collapsing and dying — sometimes at a wedding, another time at the gym or on a cricket pitch — the government of India has stressed there’s no link to the sudden cardiac death with Covid-19 vaccines.
In a PIB press release, the central government cited two scientific studies to make this assertion on Wednesday. We sought to understand and distil what the evidence cited by the government says.
What are the studies being cited?
The government on Wednesday said the Indian Council of Medical Research (ICMR) and the National Centre for Disease Control (NCDC) have been working together on finding out whether the sudden cardiac-arrest deaths are linked to Covid vaccines, as suspected by a section of people.
A study by the ICMR’s National Institute of Epidemiology (NIE) — titled ‘Factors associated with unexplained sudden deaths among adults aged 18-45 years in India: A multicentric matched case-control study’ — was done from May to August 2023.
The second is an ongoing study by the All India Institute of Medical Sciences (AIIMS), New Delhi. While this one is not yet complete, the government says early analysis of the data agrees that the vaccines are not the cause for these sudden deaths.
To understand the findings, let’s focus on the first study, which is complete and published. Let’s call that the ‘ICMR study’.
What did the study find about Covid 'link'?
It said that patients who suffered unexplained deaths were four times more likely to have been hospitalised in the past for Covid, than the general population. This is not particularly surprising. Because we know that Covid, as a disease, has long-term impact, especially if you could not recover at home and were hospitalised with a severe infection of the coronavirus.
However, notably, this is about Covid infection and hospitalisation, and not about the vaccine. In fact, the study found that those who took the vaccine were less likely to die suddenly. Primarily because, if you got the vaccine, the effect of Covid on you would be less severe anyway.
“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 the vaccination indeed reduced the risk of unexplained sudden death,” the study said.
What’s causing the sudden deaths then?
The ICMR study found that a family history of sudden death was almost three times more likely to be associated with unexplained sudden deaths. Lifestyle factors, such as current smoking status, alcohol use frequency, recent binge drinking, recreational drug/substance use and vigorous-intensity activity, were also among causes.
In fact, as compared to non-drinkers, the more the frequency of alcohol use, the higher were the odds for unexplained sudden death. Timing was key too. Binge drinking or strenuous physical activity in the last 48 hours was seen as a particular factor.
The study acknowledged that there is an increased risk of cardiovascular (heart-related) complications if you were infected by the coronavirus. But studies have also documented that the vaccination reduces the risk of severe Covid-19.
So, simply put, the vaccine reduces your chances of being hospitalised, in case you are infected by the virus. That, then, reduces the chances of heart-related complications later; and thus reduces the chances of death.
What was checked by the ICMR study?
The ICMR study on the anecdotal cases of such deaths was conducted across 47 tertiary care hospitals in 19 states or UTs. Tertiary care hospitals are usually specialised hospitals, where the most complicated cases are treated.
It covered more than 700 sudden-death cases between October 2021 and March 2023, of individuals aged 18-45 who appeared to be healthy but died of unexplained reasons between October 2021 and March 2023.
Data was collected on these people’s Covid history, including infection, hospitalisation and vaccinations, any family history of sudden deaths, smoking, drug use, drinking habits, and intense physical activity two days before death, among other related factors. The study went by the WHO standards of sample selection. It was also approved by the ethics committees of the ICMR-National Institute of Epidemiology and all the participating hospitals.
What are the big takeaways, in distilled terms?
The ICMR study concluded that the vaccination was not associated with an increased risk of unexplained sudden death among young adults. At the same time, hospitalisation for Covid-19 could be a factor, because it is indeed a serious infection that can increase the risk of heart disease. The vaccine actually reduces this risk. Lifestyle behaviours were the major risk factors.
So, can the vaccines positively stop sudden deaths? That needs further examination, says the study. But did the vaccines cause these deaths? The study gives a straight answer: No. It says that if at all the vaccines had any role, it was in fact in reducing the chances of such deaths.
The government, in its press release on Wednesday, said, “Scientific experts have reiterated that statements linking Covid vaccination to sudden deaths are false and misleading... Speculative claims without conclusive evidence risk undermining public confidence in vaccines, which have played a crucial role in saving millions of lives during the pandemic. Such unfounded reports and claims could strongly contribute to vaccine hesitancy in the country, thereby adversely impacting public health.”
