Bacterial protein could eliminate need for adjuvants in flu vaccines

Abstract

In rare cases, adjuvants included in some influenza vaccines to increase immune response can trigger serious adverse effects , such as inflammation and allergic reactions. Researchers now report that a flu vaccine using a modified bacterial protein can stimulate a strong immune response without needing an adjuvant. The vaccine candidate increased survival of mice infected with different flu viruses, opening up the possibility of using the protein in a universal flu vaccine that would not have to be reformulated each year to match the virus strains in circulation ( ACS Nano 2021, DOI: 10.1021/acsnano.1c04078 ). Sangyong Jon, Ji-Joon Song, and colleagues at the Korea Advanced Institute of Science and Technology connected a flu antigen, matrix protein 2 ectodomain (M2e), to a protein from Brucella bacteria called BP26. The bacterial protein units assembled themselves into a barrel-like nanoparticle with the flu antigens pointing outward. M2e is present in most types of