A sweeping review of data covering billions of doses of mRNA vaccines has reaffirmed the technology's safety and effectiveness against infectious diseases, with researchers calling for a renewed push to improve global access. The study, published in The Lancet, examined real-world evidence from the COVID-19 pandemic and found that mRNA vaccines remain a powerful tool against severe illness, hospitalisation, and death.
Unlike traditional vaccines, mRNA vaccines deliver genetic instructions that prompt cells to produce a harmless viral protein, training the immune system without altering a person's DNA. This platform, first deployed at scale during the pandemic, has now been validated across diverse populations and settings.
High Efficacy, Declining Protection
The review found that within 14 to 42 days of vaccination, the vaccines were 87% effective against documented SARS-CoV-2 infection, 93% effective at preventing hospitalisation, and 94% effective at preventing death. Protection waned over time, but booster doses restored much of the lost immunity, underscoring the need for ongoing vaccination campaigns.
Serious adverse events—including myocarditis, pericarditis, and anaphylaxis—were very rare. Most reactions, such as sore arms, fatigue, and fever, were mild to moderate and resolved within days. The researchers stated: "Across billions of administered doses, serious adverse events have been rare, well characterised, and consistently outweighed by the substantial protection conferred against severe disease, hospitalisation, and death."
The study highlighted effectiveness across age groups, during pregnancy, and in immunocompromised individuals, establishing mRNA vaccines as a clinically validated and adaptable platform. This is particularly relevant for European health systems, which have grappled with vaccine hesitancy and uneven booster uptake across member states from Berlin to Rome.
Beyond COVID-19: Cancer and Future Pandemics
Beyond infectious diseases, the researchers see the platform underpinning more personalised cancer treatments, with vaccines tailored to individual patients and tumour profiles. Co-author Manish Sadarangani of the University of British Columbia and BC Children's Hospital Research Institute said: "mRNA vaccines have already transformed how we respond to emerging diseases, and with ongoing innovation and rigorous safety monitoring, they can drive progress in preventive medicine and cancer treatment for years to come."
New storage options—such as higher-temperature storage and freeze-drying—are making it easier to reach remote areas quickly and reduce waste. However, the authors caution that scientific advances alone will not guarantee equitable access. Co-author Robin Shattock of Imperial College London noted: "Expanding manufacturing capacity and ensuring equitable access in low- and middle-income countries is essential if mRNA vaccines are to fulfil their promise as a global public good."
This call resonates across Europe, where the European Commission has invested heavily in mRNA production hubs in places like Belgium and Germany, but disparities persist in the Balkans and parts of Eastern Europe. The review's findings reinforce the need for coordinated EU-level strategies to bolster vaccine equity, especially as extreme heat events and other climate pressures strain healthcare systems—a challenge highlighted in our coverage of extreme heat costs in France, Italy, and Spain.
As Europe looks ahead, the mRNA platform offers a proven foundation for responding to future health crises. The review concludes that continued investment in research, manufacturing, and distribution is critical to ensuring that the benefits of this technology reach all corners of the continent and beyond.
