Mucosal vaccines for respiratory viruses is challenging: study

It is challenging to create influenza, coronavirus, and respiratory syncytial virus (RSV) vaccines that offer long-lasting defence. In a new review article in Cell Host & Microbe, researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH, explore the challenges and outline approaches to improved vaccines. Anthony S. Fauci, M.D., former NIAID director, is an author along with Jeffery K. Taubenberger, M.D., PhD, and David M. Morens, M.D.
Contrary to the respiratory viruses that cause measles, mumps, and rubella, for which vaccination or recovery from illness provides decades-long protection against future infection, flu, RSV, SARS-CoV-2, etc share several traits that enable them to cause repeated re-infections.
The authors note that mucosal immunization appears to be an optimal route of vaccination for the viruses of interest, when feasible. However, important information gaps must be filled in order to create effective mucosal vaccines which include identifying the best vaccine formulations, figuring out dosage size, frequency, and timing, and creating strategies for combating immune resistance.