Bird flu vaccine could soon be on standby in case of future outbreak: experts

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.

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 record numbers of birds and infected mammals. Human cases, however, remain very rare.

Last month, Health Canada said in an email to Global News that “human infection with avian influenza A(H5N1) is rare” and poses a low risk for the general public who have limited contact with infected animals.

Executives at three vaccine manufacturers – GSK Plc GSK.L Moderna Inc MRNA.O and CSL Seqirus, owned by CSL Ltd CSL.AX – told Reuters 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.

Others, like Sanofi SASY.PA, said they “stand ready” to begin production if needed, with existing H5N1 vaccine strains in stock.

There has also been a push among companies to develop a bird flu vaccine for poultry, a market potentially far larger than that for humans.

Less reassuring, however, is that most of the potential human doses are earmarked for wealthy countries in long-standing preparedness contracts, global health experts and the companies said.

Many countries’ pandemic plans say flu shots should go first to the most vulnerable while supply is limited. But during COVID-19, many vaccine-rich countries inoculated large proportions of their populations before considering sharing doses.