Continue to conduct studies comparing efficacy, safety, and relative effectiveness of new egg-independent production methods to each other and to egg-based methods.
Fowlkes 2024 conducted a randomized immunogenicity trial of RIV4 vs. standard-dose IIV4 among frequently and infrequently vaccinated healthcare personnel and found that RIV4 had improved immunogenicity for influenza vaccine strains compared to IIV4.
Murchu 2021 conducted a systematic review of data on the efficacy and effectiveness of trivalent recombinant HA seasonal influenza vaccines compared with conventional QIV in adults aged 50 or older.
Gouma 2022 used a murine model to directly compare nucleoside-modified mRNA-LNP vaccines expressing wild-type and egg-adapted H3 with a conventional inactivated egg-based influenza vaccine, and found that nucleoside-modified mRNA-LNP-based vaccines can circumvent problems associated with egg adaptations with recent H3N2 viruses.
Essink 2022 conducted a phase 3 RCT to evaluate the safety and immunogenicity of a cell-based QIV (QIVc) compared with egg-based QIV; QIVc was well tolerated and immune responses were similar to QIV in children 6 to 47 months of age.
Rockman 2022 examined the benefits of cell-based vaccines produced using mammalian (MDCK) or insect (baculovirus recombinant) cell lines to improve seasonal influenza vaccine effectiveness, compared with currently available egg-based production strategies.
Askar 2025 updated a previous systematic review to reassess evidence on the safety and efficacy/effectiveness of newer and/or enhanced influenza vaccines, including mRNA-based vaccines, compared with standard influenza vaccines. Newer data accumulated since 2020 were reassuring regarding safety of the vaccines. Evidence regarding relative VE of the vaccines against lab-confirmed outcomes has only slightly improved.
Izurieta 2021 compared the effectiveness of five types of conventional seasonal influenza vaccines (e.g., egg-based, recombinant, cell-based, high-dose, and adjuvanted) administered to Medicare beneficiaries ages 65 years and older.