Severe Covid-19, not vax, increases risk of cardiovascular disease

New Indian Express

3 days ago

There is no scientific evidence that Covid-19 vaccines cause sudden deaths, said Dr Rajeev Jayadevan, the co-chairman of the National Indian Medical Association (IMA) Covid Task Force. Speaking with Kavita Bajeli-Datt, the convener of the Research Cell, Kerala, IMA, however, said, there is a clear link between severe Covid-19 and increased cardiovascular risk in the months or years that follow as Covid damages the inner lining of blood vessels, which can later result in heart attacks, strokes, or other vascular events. Edited excerpts:
Karnataka Chief Minister Siddaramaiah has claimed that 'hasty approval and distribution' of Covid-19 vaccines may be responsible for over 20 apparent heart attack deaths in Hassan district. Your view?
There is no scientific evidence that Covid-19 vaccines cause sudden deaths, despite widespread speculation on social media fuelled by anti-science activists. Sudden death in young adults is a well-known phenomenon long before the pandemic, occurring at a rate of about 1 in 1,700 adults aged 35–45 annually. The causes are diverse. In older adults, heart attacks are a common cause, while in younger individuals, inherited heart rhythm disorders and structural heart diseases like cardiomyopathy are more likely. Non-cardiac causes include stroke, infections, toxins, and pulmonary embolism. Without ascertaining a clear cause of the recent deaths, speculation is misleading and unscientific.
How safe are Covid-19 vaccines?
The safety of Covid-19 vaccines has been demonstrated repeatedly through large studies in India and globally. Because vaccines activate the immune system, the resulting inflammation leads to mild side effects such as fever, body aches, and pain at the injection site. A few specific vaccines were subsequently found to have extremely rare side effects. For example, mRNA vaccines used in the US can cause myocarditis, particularly in young males, at a rate of about 1 in 37,000. Adenovirus vector vaccines can cause a rare condition called VITT (vaccine-induced immune thrombotic thrombocytopenia), with a frequency of about 1 in 50,000 to 100,000. Myocarditis usually resolves fully, while VITT can be fatal in a minority. Importantly, VITT typically occurs within two weeks of the first dose—not years later.
What explains the perceived rise in sudden heart attack deaths in India?
Sudden cardiac deaths have always occurred across all adult age groups. However, with the widespread use of smartphones and social media, such incidents are now frequently recorded and shared virally, creating the impression that these events are more common. Most cardiologists agree there is no substantial increase. However, those who had Covid-19, especially before vaccines were available, do have a modestly increased risk of cardiovascular events that can persist for up to three years. At an individual level, this risk is small and not a cause for panic.
Is there a link between Covid-19 and heart attacks?
Yes. There is a clear link between severe Covid-19 and increased cardiovascular risk in the months or years that follow. Covid damages the inner lining of blood vessels, which can later result in heart attacks, strokes, or other vascular events. This has been well-documented in numerous international studies. Importantly, those who were vaccinated and therefore experienced milder infections are less likely to develop such complications. This protective effect of vaccination has been clearly proven.
Some claim the vaccines were rushed without proper clinical trials, possibly contributing to sudden deaths. Your take?
All Covid-19 vaccines, including those used in India, underwent proper clinical trials. In the past, vaccine trials took many years to complete primarily because the diseases they targeted were rare and required longer follow-up. In contrast, Covid-19 was spreading rapidly, allowing researchers to reach statistical endpoints much faster. This speed led some to mistakenly claim that trials were 'rushed' or 'skipped'. The chief objective of the phase 3 trials was to see if people who took vaccines had a lower chance of getting Covid compared to those who were unvaccinated. It is worth remembering that Covid-19 was a global emergency killing a total of at least 7 million people, especially in the first two years of the pandemic. It is true that certain inactivated vaccines were authorised for use by many countries as soon as early trial results became available. Delaying vaccine rollout, citing reasons for full publication of all phase 3 trials in reputed medical journals would have meant that many more people would have died while waiting to receive the vaccine. This is the basis of emergency use authorisation or EUA, which was done in several countries, including ours.
How different are the vaccines used in India and the US?
The US primarily used mRNA vaccines and a smaller share of adenovirus vector vaccines. In India, about 90% of the population received adenovirus vector vaccines, while the remaining received an inactivated virus vaccine produced domestically.
The Union Health Ministry has quoted ICMR-AIIMS studies on sudden unexplained deaths and linked them to lifestyle and pre-existing conditions. Your take?
Multicentre studies in India, including those by ICMR-AIIMS, have shown that most sudden deaths since the pandemic are linked to known risk factors: family history, substance use, binge drinking, etc. Importantly, people with a history of severe Covid, especially those who resumed heavy exercise too early, are at higher risk. Those who had received two vaccine doses are less likely to die suddenly compared to unvaccinated individuals. These findings mirror results from studies worldwide.