Until recently, influenza vaccine was only manufactured in fertilized chicken eggs. However, that is not the case for the cell-based vaccines now approved down to 6 months of age. What is the difference between these 2 types of vaccines? Cell-based vaccines involve growing strains of influenza on a mammalian cell-based platform rather than in eggs and by doing so, they reduce the chances of mutations in the targeted vaccine strain from occurring.
In a study being released this month in our journal, Essink et al (10.1542/peds.2022-057509), shares with us the results of a large phase 3 randomized observer-blinded comparator-controlled trial comparing the safety and immunogenicity of the 2 types of vaccines to prevent influenza. In this new study, 2,414 children, 6 to 47 months in age, were randomized to receive 2 doses of either a cell-based or egg-based quadrivalent influenza vaccine (QIVc vs QIV) with serologic responses obtained at baseline and 28 days post-second dose. Safety metrics were also monitored for 180 days. The authors found the cell-based vaccine to be non-inferior to the egg-based vaccine in terms of immunogenicity and safety.
Why is this important? Given the need to target vaccine production to the predicted viral strains of influenza most likely to infect us each year, there is less chance that the vaccines manufactured in a cell-based vaccine will mutate away from their intended target strains used this type of technology. This study demonstrates that this approach is safe and equally effective.
To further describe the benefits of cell-based vaccine technology, we invited Drs. Jennifer Nayak and Mary Caserta from the University of Rochester to take a deeper dive in a solicited commentary (10.1542/peds.2022-058143). The authors note the strengths of this Phase 3 trial and note the importance that this approach is non-inferior. While the commentary authors point out what is still not known about the long-term efficacy of these cell-based vaccines, they believe the benefits far outweigh the risks. The science that is discussed in both the study and commentary is fascinating to learn about. This may be a game-changer for protecting children and adolescents in the upcoming flu seasons.