A universal vaccine that offers protection against multiple flu strains could soon be within reach of scientists searching for the "Holy Grail" of immunology.
Researchers have reported major progress towards creating a vaccine that could win the arms race with influenza, which continually mutates.
Both focused on the "stem" of a key component of the virus that remains unchanged in different strains. Flu jabs are currently designed around the "head" of the molecule that alters from year-to-year, making it necessary to keep updating the seasonal vaccine.
As well as being reliably effective against seasonal flu, a universal vaccine would also prevent illness caused by other viral sub-types, such as those that normally infect birds and pigs.