Billions of mRNA vaccine doses’ review underpins their effectiveness

Key facts

• A review of billions of mRNA vaccine doses found compelling evidence of their safety and effectiveness against infectious diseases.
• The vaccines were found to be 87% effective against documented SARS-CoV-2 infection, 93% effective at preventing hospitalization, and 94% effective at preventing death.
• Serious adverse events, including myocarditis and anaphylaxis, were found to be very rare.
• The mRNA platform shows potential for personalized cancer treatments.
• Researchers emphasized the need for expanded manufacturing capacity and equitable access in low- and middle-income countries.

A comprehensive review of data from billions of mRNA vaccine doses has provided compelling evidence of the technology's safety and high effectiveness against infectious diseases. The findings, published in The Lancet, indicate that mRNA vaccines remain highly effective at preventing severe disease, with serious adverse events being rare. The review found the vaccines to be 87% effective against documented SARS-CoV-2 infection, 93% effective at preventing hospitalization, and 94% effective at preventing death within a specific timeframe post-vaccination. While protection wanes over time, booster doses have been shown to restore immunity. Common side effects like sore arms, fatigue, and fever were mild to moderate and temporary. Researchers highlighted that the effectiveness spans various age groups, including pregnant individuals and immunocompromised populations, establishing mRNA vaccines as a clinically validated and adaptable platform. Beyond infectious diseases, the platform holds promise for personalized cancer treatments. However, the review also stressed that scientific advancements alone are insufficient for equitable access. Expanding manufacturing capacity and ensuring access in low- and middle-income countries are crucial for mRNA vaccines to serve as a global public good. This would involve greater investment in technology transfer, local manufacturing, and strengthened regulatory systems to shorten supply chains and reduce costs.