Broadly Reactive H2 Hemagglutinin Vaccines Elicit Cross-Reactive Antibodies in Ferrets Preimmune to Seasonal Influenza A Viruses

In this study, preimmune ferrets were vaccinated with wild-type (WT) and COBRA H2 recombinant HA proteins in order to examine the effects that preexisting immunity to seasonal human influenza viruses have on the elicitation of broadly cross-reactive antibodies from heterologous vaccination.