“Globally, no study has shown an increase in heart disease or sudden deaths among COVID-19 vaccinated individuals,” as quoted by Professor Dr Nadeem Rizvi, a senior cardiologist, talking with a Samaa news representative [1]. This statement came in light of rising concerns and misinformation on social media following the tragic, sudden death of Niaz Ahmad, a 36-year-old teacher in Lahore in early July 2025.
Dr Steven Gundry presented a non-peer-reviewed abstract in November 2021 at a medical conference, claiming that mRNA vaccines could “dramatically increase” endothelial inflammation, potentially raising the risk of future heart attacks [1]. Though the study lacked rigorous scientific endorsement, it ignited online speculation, driven largely by influential figures and conspiracy-oriented platforms that have exaggerated the link between vaccination and heart conditions.
However, it is crucial to note that the Centers for Disease Control and Prevention (CDC) has firmly concluded, since 2022, that there is no increased risk of heart defects associated with the COVID-19 vaccine. [2]
In the years following the pandemic, both Pakistan and India reported a troubling rise in sudden cardiac emergencies among younger individuals. In Karachi, for instance, experts at the Aga Khan University Hospital (AKUH) noted that cardiac emergencies had almost doubled since 2021, with cases involving patients as young as eighteen. [3]
Similarly, India’s Health Ministry acknowledged reports of sudden deaths among youths after COVID-19, and stated that there was insufficient evidence to directly link them to infection or vaccination. [4] Their local media also highlighted a worrying increase in heart attacks among young people, sparking public concern, even as doctors cautioned that lifestyle and genetic risk factors could also play a role.
When Niaz’s death was captured on video and widely shared, it quickly merged into a larger narrative shaped by earlier cases. People started linking these sudden deaths since 2021 to COVID-19 vaccines, drawing on previous non-peer-reviewed research. The panic spread quickly as communities searched for answers.
What were the facts?
While COVID-19 vaccines are generally safe, ongoing safety monitoring has identified rare adverse events, such as myocarditis and pericarditis, which are primarily associated with mRNA vaccines. These were quickly investigated by regulatory bodies such as the EMA’s PRAC [5].
Peer-reviewed research proved that COVID-19 vaccines may cause myocarditis, which is an inflammation of the heart muscle. Most cases linked to COVID-19 mRNA vaccines are mild, temporary, and resolve without long-term effects. Similarly, global surveillance and studies have also found a risk of myocarditis following mRNA vaccination, especially in males aged 12–30, typically occurring within 1–14 days after the second dose.
Israeli health records also show that while mRNA vaccination increases myocarditis risk, SARS-CoV-2 infection poses a much greater risk. [5]
Is the Myocarditis Risk before Vaccination higher than after Vaccination?
There is a slight chance of myocarditis after vaccination, but let’s be honest. Before the vaccine rollout, COVID-19 infection itself was already associated with a significantly higher risk of myocarditis, about 16 times greater than in uninfected individuals. Significantly, myocarditis following vaccination is associated with significantly lower mortality compared to myocarditis caused by the virus.
In the EU and European Economic Area, mRNA vaccines were widely used and deployed earlier than other vaccine types. While they are associated with a small increase in myocarditis risk, the overall benefit far outweighs the risk. The exact biological mechanism behind vaccine-associated myocarditis remains unknown, and further research is ongoing [5].
Cases with Irregular Heartbeat after the COVID-19 Vaccine
Atrial fibrillation (AF), a type of irregular heartbeat, has been rarely reported after COVID-19 vaccination. Although heart-related side effects after immunization were uncommon, there hasn’t been much data specifically about AF.
To learn more, researchers looked at reports from VAERS, a U.S. vaccine safety system run by the CDC and FDA. They reviewed AF cases reported up to January 7, 2022, after people received the Pfizer, Moderna, or Johnson & Johnson vaccines. They also checked a global safety database from the World Health Organization (called VigiBase), which showed only 35 cases of AF among 5,000 heart-related vaccine reports. This suggests that AF is an infrequent short-term side effect of COVID-19 vaccination [2].
What’s to Conclude?
The above data revealed that scientific misinterpretation can contribute to misinformation, causing widespread public fear and eroding confidence in life-saving interventions. Despite ongoing social media speculation, scientific data show no increase in heart disease or sudden cardiac deaths due to COVID-19 vaccines.
Rare side effects like myocarditis and atrial fibrillation (AF) have been documented after mRNA vaccination, but they are usually mild, temporary, and occur within days after vaccination.
These events were thoroughly investigated by global health authorities like the CDC, FDA, and EMA, all of which confirmed that the benefits of vaccination far outweigh the risks. In fact, COVID-19 infection itself poses a much greater risk of causing heart complications than the vaccine.
References:
- https://www.google.com/search?q=1.+https%3A%2F%2Fwww.samaa.tv%2F2087335945-covid-19-vaccine-linked-to-heart-attacks-experts-
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9175153/#:~:text=A%20total%20of%202611%20events,COVID%2D19%20vaccine%20doses%20administered
- https://tribune.com.pk/story/2565513/post-covid-spike-in-heart-diseases-causes-alarm
- https://www.newindianexpress.com/nation/2023/Jul/21/sudden-deaths-among-some-youths-aftercovid-19-but-no-sufficient-evidencecentre-2597171.html
- https://www.nature.com/articles/s41541-024-00893-1
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Bibi Khola Batool is an M.Phil. Graduated in Zoology from the University of Haripur, Pakistan. She has worked as a Teaching and Research Assistant at the Department of Biology, University of Haripur. Her research background and interest in science communication drive her to explore complex scientific and societal issues, making them more accessible to the public.
