01/07/2026 - 7:01 GMT+2
The mRNA vaccine — first deployed at scale during the COVID-19 pandemic — remains highly effective at preventing severe disease and serious adverse events remain rare, according to the review, published in The Lancet.
Unlike traditional vaccines, mRNA vaccines deliver genetic instructions that prompt cells to produce a harmless viral protein, training the immune system to recognise and fight infections without altering a person's DNA.
The scientific journal review found the vaccines were 87% effective against documented SARS-CoV-2 infection, 93% effective at preventing hospitalisation and 94% effective at preventing death within 14 to 42 days of vaccination. Protection declined over time, but booster doses restored much of the lost immunity.
Serious side effects, including myocarditis, pericarditis and anaphylaxis, were found to be very rare. Most reactions, such as sore arms, fatigue and fever, were mild to moderate and resolved within a few days.
