Claudia Arevalo and her colleagues developed a vaccine containing mRNA lipid nanoparticles antigens Among all 20 known subtypes of influenza viruses are A and B, a strategy that may serve as the basis for universal influenza vaccines.
Their vaccine produced high levels of subtype-specific cross-reactive antibodies in mice and rodents and could protect the animals from symptomatic disease and death after infection with both antigenic and matched strains of influenza. Even with increased global surveillance, it is difficult to predict which strain of influenza will cause the next influenza pandemic, which makes a universal vaccine important.
Arevalo approach et al. It differs from previous attempts to formulate a universal influenza vaccine by including antigens specific to each subtype, rather than just a smaller set of antigens shared between subtypes. After the success of mRNA vaccines against SARS-CoV-2, the researchers prepared 20 mRNAs coated with different nanoparticles, each encoding a different hemagglutinin antigen — a highly immunogenic influenza protein that helps the virus enter cells. Antibody levels remained mostly stable four months after vaccination in mice. Polyvalent protein vaccines produced using more conventional methods produced fewer antibodies and were less protective compared to the polyvalent mRNA vaccine in animals.
In a related perspective, Allison Kelvin and Daryl Falzarano discuss the findings, noting that “questions remain regarding the regulation and approval pathway for such a vaccine that targets viruses with pandemic potential but not currently in circulation in humans.”
Arevalo, CP, et al. (2022) A nucleoside-modified polyvalent mRNA vaccine against all subtypes of influenza virus. Sciences. doi.org/10.1126/science.abm0271.