Time to let go of vaccine fears

FOR years, a lingering question has shadowed COVID-19 vaccination campaigns: are mRNA vaccines safe in the long run. While early trials and real-world data quickly established that these vaccines reduced severe illness and deaths in the months following injection, scepticism never entirely disappeared. Instead, as the pandemic receded, concerns shifted towards a more unsettling possibility, that hidden harms might surface years later.

That anxiety has now been tested against some of the strongest evidence yet assembled. In 2025, a landmark national study from France, published in JAMA Network Open and led by Laura Semenzato, examined long-term mortality outcomes in more than 28 million adults aged 18 to 59. Its conclusion was unambiguous. A causal link between mRNA COVID-19 vaccination and excess long-term mortality appears highly unlikely.

The study followed individuals from late 2021 through March 2025, drawing on the French National Health Data System. Of the cohort, 22.8 million people received at least one dose of an mRNA vaccine during France’s mass rollout, while 5.9 million were unvaccinated. Over the 4-year follow-up period, 0.4 per cent of vaccinated individuals died, compared with 0.6 per cent of those who were not vaccinated.

After adjusting for age, pre-existing health conditions and socioeconomic factors, vaccination was associated with a 25 per cent lower risk of death from all causes. Some of this difference was expected. Vaccinated individuals were 74 per cent less likely to die from severe COVID-19. What mattered more for long-term safety concerns, however, was that the protective association persisted even after COVID-related deaths were excluded from the analysis.

The researchers also examined cause-of-death data, directly addressing fears that vaccination might increase deaths from cancer, heart disease or other chronic conditions. No such signal was found. Cancer mortality was slightly lower among vaccinated individuals, as were deaths from circulatory diseases and external causes such as accidents or suicides. Not a single category showed an increase in mortality linked to vaccination.

By the standards of observational research, this was as comprehensive a test of long-term vaccine safety as could reasonably be conducted. Yet public anxiety has remained stubbornly alive.

The reason lies less in the data than in what happened outside the datasets. In recent months, a series of sudden deaths among young people, widely reported and often poorly contextualised, reignited fears that something had gone wrong. In public perception, these tragic events became entangled with vaccination, even when no evidence supported such a connection.

This is where evidence from India becomes especially relevant. A one-year autopsy-based observational study conducted at AIIMS Delhi, published in the Indian Journal of Medical Research, examined sudden deaths among adults aged 18 to 45 using verbal autopsies, post-mortem imaging, histopathology and multidisciplinary review. The findings were clear. There was no statistically significant association between COVID-19 vaccination status and sudden deaths among young adults.

Instead, the most common cause was underlying coronary artery disease, followed by respiratory illnesses and other non-cardiac conditions. Vaccination history and prior COVID-19 infection were comparable across age groups. The study reaffirmed what cardiologists have long warned, that undiagnosed cardiovascular disease remains a major but under-recognised risk in younger populations.

These findings align with the French mortality data at a different level of analysis. One examines population-wide trends over years. The other scrutinises individual deaths in forensic detail. Both point in the same direction. Vaccination is not driving sudden or delayed mortality. So why did fear persist.

Part of the answer lies in how humans perceive risk. A single unexplained death, especially of a young and seemingly healthy person, carries enormous emotional weight. Large population studies speak in probabilities and percentages, while individual tragedies speak directly to fear. The mind is inclined to connect dramatic events to the most salient recent intervention, even when the link is coincidental.

The pandemic environment amplified this tendency. Vaccines were rolled out at unprecedented speed, under emergency conditions, during a period of collective trauma. Although mRNA technology had been researched for decades, its first mass deployment coincided with lockdowns, mandates and deep social disruption. Speed became conflated with insufficient testing, despite extensive trials and continuous safety monitoring.

Communication missteps compounded the problem. Early public messaging sometimes leaned towards certainty rather than transparency about evolving evidence. When guidance later changed on boosters or eligibility, scientific adaptation was misread as inconsistency or concealment. In that vacuum, speculation flourished.

Social media accelerated the spread of fear. Anecdotal reports of illness or death circulated without medical context, while adverse event reporting systems were repeatedly misrepresented as proof of causation rather than surveillance tools designed to flag signals for investigation. Corrections rarely travelled as far as claims.

There was also a broader erosion of institutional trust. Pandemic responses relied heavily on emergency powers, uneven enforcement and, at times, inadequate explanation. For many citizens, vaccines became symbols of compulsion rather than public protection. Scientific findings, including those from respected institutions such as AIIMS, were filtered through this distrust.

The French study directly addressed another lingering suspicion, that vaccinated people might simply be healthier to begin with. In fact, vaccinated individuals in the cohort were slightly older and more likely to have cardio-metabolic disease, factors that usually increase mortality risk. Yet their overall risk of death was lower. While no observational study can eliminate all bias, the scale, duration and methodological rigour of the analysis leave little room for claims of hidden long-term harm.

Taken together, the evidence now spans both breadth and depth. After four years of follow-up across tens of millions of people, and detailed autopsy-based investigation of sudden deaths among young adults, there is no signal that mRNA COVID-19 vaccines increase long-term mortality.

The remaining challenge is not scientific but social. Sudden deaths among young people are real and deeply distressing. They warrant focused public health action, including better cardiovascular screening, lifestyle interventions and earlier diagnosis. What the evidence does not support is attributing these deaths to vaccination.

The long-term safety question was legitimate. It has now been examined with unprecedented scrutiny. 

On current evidence, mRNA vaccines have passed that test.

The writer comments on health issues, focusing on nutrition, public health policy, and non-communicable diseases.