US to vaccinate California Condors against bird flu

US officials have authorised the vaccination of Critically Endangered California Condors against bird flu.

It represents the first time that the country has given the green light to inoculation of any bird against highly pathogenic avian influenza (HPAI). The approval comes as the H5N1 strain has spread to an unprecedented number of countries, lasted longer than a typical outbreak and killed hundreds of millions of birds across the world.

The US is set to vaccinate California Condors against bird flu (Alexander Viduetsky).

Some countries already vaccinate birds, including commercial flocks. The severity of the outbreak is driving some nations that have been hesitant, including the US, to follow suit. 

The decision to vaccinate the raptors does not mean that authorities are planning to do so with the country's poultry stock, although researchers will be watching how the campaign goes closely.

So far this year, officials have found 21 dead condors, 15 of which tested positive for HPAI. Deaths were first reported in mid-April and the news came as deep concern to conservationists, given the precarious state of the bird's recovering population in North America.

The strain of HPAI that is currently spreading first infected birds in China in 1996 and has since caused irregular outbreaks that usually flare up in the autumn and vanish by the following spring. However, since late 2021, outbreaks have persisted through the summer in a record number of bird species, along with some mammals.

Several vaccines against H5N1 are available, but administering the jab to birds has long been controversial among researchers and farmers. Poultry producers worry about the cost and difficulty of vaccinating millions of birds, as well as trade restrictions.