Some of the world's leading makers of flu vaccines say they could make hundreds of millions of bird flu shots for humans within months if a new strain of avian influenza ever jumps across the species divide.
One current outbreak of avian flu known as H5N1 clade 2.3.4.4b has killed a record number of birds and infected mammals. Human cases, however, remain very rare, and global health officials have said the risk of transmission between humans is still low.
Executives at three vaccine manufacturers — GSK, Moderna and CSL Seqirus, owned by CSL — said they are already developing or about to test sample human vaccines that better match the circulating subtype, as a precautionary measure against a future pandemic.