COVID-19 proof-of-concept paves way for mRNA-based flu vaccines

The urgency of the COVID-19 pandemic spurred the development of the first mRNA vaccines approved for use in humans following decades of research, undoubtedly triggering a new era of vaccine development.

Success against COVID-19 has acted as an unexpected proof-of-concept for mRNA vaccines, with the technology now expanding to flu vaccines. Sanofi and Translate Bio launched the first clinical trial of a seasonal mRNA influenza vaccine with a monovalent candidate, followed by Moderna’s quadrivalent candidate, mRNA-1010.

Flu vaccine effectiveness ranges from 40-60% during seasons when the flu-vaccine is well-matched to circulating viruses. In contrast, COVID-19 mRNA vaccines were 94-95% effective in clinical trials. Although many factors impact effectiveness, mRNA vaccines could help flu vaccines be more effective.

Current flu vaccines are created 6-9 months before their intended use. mRNA vaccines can be developed in about a month, allowing strain predictions to be closer to the intended flu season and potentially more accurately matched. Conventional flu vaccine production via growth in chicken eggs can introduce mutations into vaccines and reduce effectiveness. mRNA vaccines are developed egg-free, reducing the mutational risk and also offering a safe option for those with egg allergies.

Flu vaccine uptake in Canada is only about 40% and 41% of Canadians surveyed believed the flu vaccine does not work. mRNA vaccines may offer greater effectiveness and confidence in flu vaccines to promote their uptake in the future.

- Andrea B.