The point of a universal vaccine is that when something like H5N1 jumps species from birds to humans that the antibodies to the hemagglutinin stem will work acr

The point of a universal vaccine is that when something like H5N1 jumps species from birds to humans that the antibodies to the hemagglutinin stem will work across all influenza A viruses. The word "subtypes" in the title is much broader than variants. And it may not prevent infection but it could take some 1918-like novel influenza pandemic that would be 10x more lethal than the coronavirus pandemic we just suffered and turn it into the 2009 H1N1 pandemic (for everyone who bothered to get vaccinated anyway).