https://www.newscientist.com/article/2348576-promising-universal-flu-vaccine-could-protect-against-20-strains/

News about a new multivalent mRNA vaccine that elicits distinct antibody lineages against all twenty influenza hemagglutinin surface proteins (HAs) in mice and ferrets. Importantly, the vaccine eleicited strong antibody responses in animals with or without prior exposures, suggesting that the vaccine could be used in children as well as in those who have already encountered the flu.