From top scientists and senior doctors to government health agencies, pharmaceutical leaders, and industry associations — a unified chorus has risen in defense of Covid-19 vaccines, firmly rejecting any link to sudden cardiac deaths.
In fact, they emphasized that had the vaccines not been administered, the death toll from the deadly virus — which swept across the world in multiple waves — would have been significantly higher.
This comes in the wake of Karnataka Chief Minister Siddaramaiah's recent remarks suggesting a possible association between the vaccines and fatalities among young adults in Hassan district.
Addressing a press conference here on Thursday, senior doctors from the All India Institute of Medical Sciences (AIIMS), Delhi, sought to clarify that ongoing research has found no causal link between Covid-19 vaccination and sudden unexplained deaths. Instead, most such deaths have been due to lifestyle factors such as smoking, obesity, hypertension, stress, and alcohol consumption.
Dr. Abhishek Yadav, Additional Professor, Department of Forensic Medicine at AIIMS, detailed two studies led by the institute. A retrospective analysis comparing data from 2018 to 2022 found no surge in sudden cardiac deaths post-vaccination. A second, ongoing study launched in collaboration with the ICMR in 2023, has so far examined 230 deaths, employing genomic and virtual autopsy methods.
“Our interim findings show no evidence linking COVID-19 vaccines to sudden cardiac deaths,” said Dr. Yadav. The study categorized cases into two age groups—18–45 years and 45–65 years—with coronary artery disease and substance use emerging as prominent contributing factors.
Approximately 25% of deaths remain unexplained, and genomic studies are underway to investigate possible genetic mutations or molecular anomalies. Dr. Sudheer Arava, Professor in the Department of Pathology at AIIMS, said that among the studied cases, nearly 50% were found to be due to myocardial infarction. He also asserted that the term “heart attack” is loosely used by the general public to describe all sudden deaths, even though the actual causes vary significantly.
Dr. Sanjay Rai, Professor of Community Medicine at AIIMS, highlighted that the Covishield vaccine, developed by Oxford–AstraZeneca, had an efficacy of 62.1%. He underscored that all vaccines approved in India—whether vector-based, inactivated, or mRNA—had passed through rigorous clinical evaluations before receiving Emergency Use Authorization.
“The WHO currently recommends vaccination for all individuals aged six months and above,” he noted, stressing the continued importance of immunization against evolving variants.
Dr. S. Narang, senior cardiologist at AIIMS, opined that in older adults, heart attacks typically occur due to blocked arteries caused by plaque rupture and clot formation, which cuts off blood supply to the heart.
“In younger people, sudden cardiac events are often linked to rhythm disorders or structural heart defects.” He was of the view that post-Covid health awareness and social media have made such incidents seem more common than before.
Dr. Karan Madan, Associate Professor in Pulmonary Medicine at AIIMS, echoed similar views as he described the vaccines as “the only viable tool available at the time to curb mortality.” He cited data that supported no clear association between vaccine use and sudden cardiac events while Dr. Tulika Seth, HOD of Hematology Department said that in a special clinic for blood clotting which they have been running for the last 25 years they have found that it is the nature of the vaccine that can cause blood clots.
Thrombosis i.e. blood clots also occur among people. During the time of Corona, due to the high infection of its virus, blood clotting was also very high, in which normal medicine did not work to thin the blood. In such a situation, people should still keep getting tests related to it due to genetic problems.
The Indian Council of Medical Research (ICMR) and the National Centre for Disease Control (NCDC) have also been conducting investigations into unexplained sudden deaths, particularly in young adults aged 18–45 years. Two complementary studies have been undertaken to address concerns.
The first, led by ICMR’s National Institute of Epidemiology (NIE), was a multi-centre matched case–control study conducted between May and August 2023. It analyzed sudden deaths among individuals who had appeared healthy but died between October 2021 and March 2023. The study found no increased risk of unexplained sudden death due to Covid-19 vaccination.
The second, still underway at AIIMS with ICMR support, is a prospective study aimed at determining the most common causes of sudden deaths in young adults. Preliminary findings suggest myocardial infarction as the leading cause, with no notable deviation from patterns seen in pre-pandemic years. Genetic factors are being probed in cases where no obvious cause is found.
Soon after the Karnataka government expressed its doubt over the efficacy of the covid jabs and called for the probe early this month, the Union Health Ministry came out with a statement saying, “Speculative claims without scientific basis risk undermining public trust in vaccines, which were instrumental in preventing millions of deaths globally.”
Leading voices from the pharmaceutical and scientific community also weighed in. Kiran Mazumdar-Shaw, Executive Chairperson of Biocon, wrote on X, that the vaccines developed in India were approved following stringent protocols aligned with global standards. “To suggest they were hastily cleared is factually incorrect. These vaccines saved lives,” she said, while, a day later, welcomed the investigation in Hassan for the sake of transparency.
“India-made vaccines are safe, effective & trusted in 90+ countries, backed by WHO & used worldwide. They helped end polio & fight COVID. At a time when India is seen as a vaccine leader, let’s build trust in science, not doubt it. Public health must stay above politics,” said Satish Reddy, chairman of Dr. Reddy's Laboratories on X.
Pankaj Patel, chairman and promoter of Zydus Lifesciences also expressed his views in the matter as he posted, that there are "other multiple reasons, like age, environmental factors, genetics, lifestyle, etc., that could be the leading cause of heart attacks in people. Several scientific studies globally and in India have conclusively shown that the risk of heart attack or myocarditis is greater after SARS-CoV-2 infection. It has been proven beyond doubt that vaccination remains the most effective and preventive healthcare strategy to reduce deaths and disabilities". Sudarshan Jain, Secretary General of the Indian Pharmaceutical Alliance (IPA), also warned that misinformation could seriously undermine public health. “Vaccines went through documented, regulated testing and were a cornerstone of our pandemic response,” he noted.
The Indian Vaccine Manufacturers Association reiterated that all vaccines approved for use in India underwent preclinical and clinical trials demonstrating safety, efficacy, and immunogenicity.
