The U.S. Fish and Wildlife Service’s Incident Command Team, in collaboration with partner agencies, continues to develop and implement conservation strategies to help California condors as Highly Pathogenic Avian Influenza (HPAI) spreads on the landscape during fall migration season.
In the upcoming weeks of November, partners operating California condor release sites in northern, central and southern California will begin releasing the first HPAI vaccinated condors into the wild. The timing of the releases will continue to be dependent on the individual condor’s behavior and local weather conditions at the release site.
Consistent with our previous report, the release birds have or will receive two 0.5ml doses of the vaccine, either as part of the trial or at the release site. The condors are being vaccinated by veterinarians licensed in the state according to approved site-specific plans. Based on trial results, we expect the vaccine will provide the birds some level of protection from mortality if exposed to the virus.
Prior to expanding the use of the vaccine in captive and free-flying condors, the Service will (1) complete the current vaccine trial (2) evaluate changes in the level of antibodies in vaccinated condors, and (3) evaluate the condors in the Arizona/Utah population, which may have been previously exposed to the virus and survived, for antibodies.
The Service would like to thank and acknowledge all partners whose contributions have assisted in implementing the vaccination trial and supporting our ability to take this step of releasing condors vaccinated for HPAI.
California Condor Vaccination Trial (no change)
Final analysis for the samples from Group 1 for condors are complete. USDA’s Southeast Poultry Lab conducted hemagglutination inhibition tests on serum samples collected 42 days after the vaccination. The samples were evaluated for antibody titers that are commonly used as surrogate markers against influenza and other pathogens. Final analysis of Group 2 is pending.
Group 1 received a vaccination of 0.5ml on two occasions (initial injection and booster).
- Results show that 60% of the condors had titers that are expected to provide partial protection against mortality, while 10% of those birds had titers expected to provide protection against mortality.
Group 2 received a single 1 ml dose vaccine.
- 10 condors completed vaccine administration.
- 10 condors have completed the 42-day trial period.
Group 3 includes control birds. They will not receive vaccines, but blood samples were collected.
Additional hemagglutination inhibition tests are being conducted to provide a better understanding on the duration the birds may be protected and to what extend from the currently circulating strain of HPAI.