A landmark global review published in The Lancet has delivered one of the strongest scientific endorsements yet of mRNA vaccines, concluding that the technology behind billions of COVID-19 vaccine doses is both safe and highly effective, even as misinformation continues to fuel public concerns worldwide.

The review, led by researchers at the University of British Columbia (UBC), brings together laboratory research, clinical trial findings and real-world evidence from the largest vaccination campaign in history. The authors say that the results answer long-standing questions about vaccine safety and also set the stage for future vaccines against influenza, respiratory syncytial virus (RSV), cancer, and some autoimmune diseases.

"After billions of doses, we now have an extraordinary amount of scientific evidence," said lead author Dr Anna Blakney, assistant professor at UBC's Michael Smith Laboratories and School of Biomedical Engineering. "This review affirms that mRNA vaccines are a safe and highly effective platform, supported by rigorous testing and real-world monitoring. It provides an evidence-based foundation as this technology continues to expand into new areas of medicine."

The review reinforces conclusions reached by health agencies, including the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC), which have consistently found that the benefits of COVID-19 vaccination far outweigh the risks for most people.

Researchers acknowledged that, like all vaccines, mRNA vaccines can cause side effects. Rare cases of myocarditis—an inflammation of the heart muscle seen more often in younger males—have been reported. However, the review found that such events remain uncommon and are greatly outweighed by protection against severe illness, hospitalisation and death from COVID-19.

The paper also addresses one of the most common myths surrounding the technology. Unlike genetic modification, mRNA does not alter human DNA. Instead, it acts like a temporary set of instructions that tell cells to make a harmless piece of the virus, allowing the immune system to recognise and fight the real virus later. Both the mRNA and the tiny fat particles, known as lipid nanoparticles, that deliver it into cells are naturally broken down and cleared from the body within a short time.

"With any new vaccine or medicine, we must clearly and transparently communicate the safety data and rigorous testing that supports their use," said co-author Dr Manish Sadarangani, professor of paediatrics at UBC and director of the Vaccine Evaluation Centre at BC Children's Hospital Research Institute. "This is essential for building public trust, countering misinformation, and supporting informed decisions about vaccination."

Beyond COVID-19, researchers say the same technology is already being adapted to develop vaccines against influenza and RSV, alongside personalised cancer vaccines designed to train the immune system to attack individual tumours.

"This is really about what comes next," Dr Blakney said. "We're seeing the same platform being applied to cancer treatment and other diseases. Understanding how these vaccines work—and why they're safe—helps build confidence in the next generation of medicines."

The authors conclude that continued safety monitoring, transparent communication and wider global access will determine how successfully mRNA technology shapes the future of disease prevention.