A sweeping new scientific review has reaffirmed that mRNA COVID-19 vaccines are safe and effective, and that getting vaccinated is safer than catching the virus itself. The Canadian-led analysis pulled together evidence built up over five years and billions of doses, arriving at a reassuring bottom line for a technology that has faced persistent public doubt.
The review was published in the medical journal The Lancet. It was led by Dr. Manish Sadarangani and his co-authors at B.C. Children's Hospital, who combed through laboratory research, clinical trials and real-world surveillance of the Pfizer-BioNTech and Moderna vaccines from January 2020 through December 2025.
On effectiveness, the numbers were strong. The review reported that the vaccines were roughly 87 per cent effective against any documented SARS-CoV-2 infection, about 93 per cent effective against hospitalization and around 94 per cent effective against death within 14 to 42 days of vaccination.
The core safety message centered on a direct comparison. While heart inflammation is a rare side effect of the shots, the researchers stressed that catching COVID puts people at a far higher risk of those exact same heart problems, meaning the protection offered by vaccination heavily outweighed the risks.
The review did not gloss over the side effect that has drawn the most attention. It found that rates of myocarditis were low but highest in young males between 12 and 19 after their second dose, with the incidence estimated at roughly 12.6 cases per million for the Pfizer-BioNTech vaccine and about 35.6 cases per million for Moderna's, supporting continued vigilance.
What set the analysis apart was its scale. The authors drew on data from billions of administered doses across diverse populations, including children, pregnant people and immunocompromised patients, giving the review a broader scope than the individual studies that came before it.
The researchers also reflected on why the vaccines have remained so contested. They suggested people may be understandably confused, and that much of the pushback was tied to the association of vaccines with mandates and questions of personal choice, rather than to any inherent problem with the shots themselves.
The review closed on a forward-looking note. mRNA technology, which was being developed to target cancer cells long before the pandemic, is now in clinical trials for several major cancers, and scientists hope that a proven safety and effectiveness track record with COVID vaccines will help build trust in what may come next.