Lancet Review Finds mRNA Vaccines Safe and Highly Effective Against Infectious Diseases - Video

Messenger RNA (mRNA) vaccines are safe and highly effective against infectious diseases, according to a comprehensive review published in The Lancet. Researchers analyzed evidence from billions of vaccine doses administered worldwide and concluded that the benefits of mRNA vaccines far outweigh their risks, reinforcing their role as a major advancement in modern medicine.

The review, led by scientists from the University of British Columbia, the London School of Hygiene & Tropical Medicine, and collaborating institutions, examined data from clinical trials and real-world safety monitoring.

The findings showed that mRNA vaccines provide strong protection against severe illness across different age groups, including children, pregnant women, older adults, and people with weakened immune systems.

Unlike traditional vaccines, mRNA vaccines do not contain live or inactive viruses. Instead, they deliver temporary genetic instructions that prompt cells to produce a harmless viral protein, training the immune system to recognize and fight future infections. Researchers emphasized that the mRNA never enters the cell nucleus, does not alter DNA, and naturally breaks down after completing its task.

The review found that booster doses improve and extend protection, particularly as new virus variants emerge. While mild side effects such as injection-site pain, fatigue, and fever are common, serious adverse events remain rare. Cases of myocarditis have been reported more frequently in younger males, but researchers noted that the risk is very low and substantially outweighed by the vaccines' ability to prevent severe disease, hospitalization, and death.

Beyond infectious diseases, scientists are exploring mRNA technology for influenza, respiratory syncytial virus (RSV), personalized cancer vaccines, and other RNA-based therapies. The authors also emphasized the need to expand vaccine manufacturing in low- and middle-income countries through technology transfer, local production, and stronger regulatory systems to improve global access and prepare for future health emergencies.

REFERENCE: Blakney A, Top K, Cowling B et al.; Safety and efficacy of mRNA vaccines: a mechanistic and public health perspective; The Lancet, 2026; DOI: 10.1016/S0140-6736(26)00512-X