A sweeping global review research has found that mRNA vaccines are safe and highly effective at preventing infectious diseases, such as COVID-19. These vaccines also have potential applications for a range of other diseases, including influenza, respiratory syncytial virus (RSV), cancer, and autoimmune disorders.
Published this week in The Lancet, the review draws on laboratory science, clinical trials, and real-world effectiveness data to provide one of the most comprehensive assessments of mRNA vaccines to date. It spans the full vaccine lifecycle, from design and manufacturing to real-world performance and monitoring.
With any new vaccine or medicine, it is important that we clearly and transparently communicate the safety data and rigorous testing that supports their use.
– Dr. Manish Sadarangani
“With any new vaccine or medicine, it is important that we clearly and transparently communicate the safety data and rigorous testing that supports their use,” says Dr. Manish Sadarangani, co-author of the study, an investigator and director of the Vaccine Evaluation Center at BC Children’s Hospital Research Institute (BCCHR), and professor in the Department of Pediatrics at the University of British Columbia (UBC). “This is essential to building public trust, countering misinformation, and supporting informed decisions about vaccination.”
By bringing this evidence together in a single resource, the researchers aim to support health-care providers, policymakers, and the public with clear, evidence-based information as new mRNA vaccines and therapies are developed.
Researchers found that serious adverse events caused by mRNA vaccines are rare and consistently outweighed by the vaccines’ protection against severe illness, hospitalization, and death.
“After billions of doses, we now have an extraordinary amount of scientific evidence,” says Dr. Anna Blakney, lead author and 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 researchers emphasize that, like all vaccines, mRNA vaccines can have side effects. They found that serious adverse events — such as myocarditis, which occurs more frequently in younger males — are rare and consistently outweighed by the vaccines’ protection against severe illness, hospitalization, and death.
After billions of doses, we now have an extraordinary amount of scientific evidence.
– Dr. Anna Blakney
The findings confirm that mRNA vaccines provide strong protection against infectious diseases — such as severe COVID-19 — across a wide range of groups, including children, pregnant people, and those who are immunocompromised. Booster doses were found to extend and strengthen that protection over time, and regular updates to the vaccine formulation maintained efficacy as new variants emerged.
The review addresses persistent misconceptions about how mRNA vaccines work, clarifying that they don’t alter a person’s DNA. Instead, mRNA — encapsulated in a lipid nanoparticle delivery system pioneered by UBC researchers — provides temporary instructions that allow human cells to produce a harmless piece of a virus, training the immune system to respond. Both the mRNA and lipid nanoparticles are quickly broken down and cleared from the body after use.
Researchers are also developing vaccines for diseases such as influenza and RSV, as well as personalized cancer vaccines and other RNA-based therapies.
Beyond COVID-19, the findings point to a rapidly expanding future for mRNA technology. Researchers are already developing vaccines for diseases such as influenza and RSV, as well as personalized cancer vaccines and other RNA-based therapies. “This is really about what comes next,” says Dr. Blakney. “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 highlight the importance of trust, access, and equity. While mRNA vaccines have proven highly effective, global uptake has been uneven, shaped in part by misinformation and historical public mistrust in health systems. Rather than dismissing vaccine hesitancy, the researchers argue it should be met with better communication and accessible, evidence-based information.
The review calls for increased investment in manufacturing capacity, as well as continued innovation to improve storage, distribution, and cost.
“People should feel empowered to ask questions about their health and what they put in their bodies,” said Dr. Blakney. “Our goal is to provide clear, credible evidence to inform these conversations and decisions.” Expanding access will also be critical to realizing the full potential of mRNA technology. The review calls for increased investment in manufacturing capacity, particularly in low- and middle-income countries, as well as continued innovation to improve storage, distribution, and cost.
“mRNA vaccines have already changed how we respond to global health threats,” says Dr. Sadarangani. “With sustained innovation, strong safety monitoring, and a commitment to equitable access, they can play a major role in preventing disease and improving health.”
Note: This study was supported by salary awards from the Canada Research Chairs program, Michael Smith Health Research BC, and BC Children’s Hospital Foundation.
Credit: Adapted from story published by the University of British Columbia
