California Condor - Photo Credit Don Graham
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Over April and May we followed reports of highly endangered California Condors (all in Arizona) infected by avian H5N1 (see USFWS Update: 21 Condor Deaths Attributed To HPAI H5). With only about 500 birds remaining in captivity or in the wild, avian flu poses a genuine risk to the survival of the species.
In mid-May we saw plans announced to use H5N1 poultry vaccines to protect these birds, but first they needed to be safety-tested on other (similar, but non-endangered) scavenger birds. Captive North American vultures in North Carolina were selected.
The USDA described the project as follows:
The authorized vaccine is a killed, inactivated product conditionally licensed by APHIS’ Center for Veterinary Biologics in 2016. Since the vaccine has not previously been tested against this strain of the virus in these species, the first step in the vaccination program is a pilot safety study in North American vultures, a similar species, to investigate if there are any adverse effects before giving the vaccine to the endangered condors. This trial is funded by the U.S Fish and Wildlife Service and will be carried out with the surrogate vultures in North Carolina beginning in May 2023.
On Friday the U.S. Fish and Wildlife Service (FWS) released the following update, announcing positive preliminary results from the safety-test in vultures, and plans to vaccinate 3 captive Condors next week. I'll have a postscript after the break.
California Condor HPAI Response Update - July 14, 2023
Jul 14, 2023
Media Contacts
Joanna Gilkeson
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 in light of Highly Pathogenic Avian Influenza (HPAI). Strategies include implementation of vaccine trials, field monitoring, and adaptation of current management practices to be increasingly nimble and flexible to improve response to future HPAI outbreaks.
INCIDENT UPDATE
Black Vulture Vaccination Trial Results
A vaccine-induced immune response has been detected in all black vultures that received the HPAI vaccination at Carolina Raptor Center after performing an enzyme-linked immunosorbent assay (ELISA) test on the samples. Titers (concentration of antibodies) present in the birds are still being evaluated by USDA’s Southeast Poultry Research Laboratory through refined testing methods to improve clarity in the results.
California Condor Vaccination Trial
Vaccination of condors in managed care will begin next week with three condors. If these birds do not show any adverse effects from the vaccine (e.g., swelling at injection site, poor health), the trial will continue the following week with additional condors. Blood samples from the birds will be collected 21-days and 42-days following vaccination to evaluate the immune response. Trials will run into September.
Ongoing Field Operations
The California Condor Recovery Program continues to implement standard operations and we are hopeful this will include the release of juveniles this year. However, due to the dynamic nature of HPAI outbreaks, and logistics around potential future vaccinations, adjustments will be made accordingly.
Tests conducted in the Netherlands earlier this year (see WUR: 2 of 4 H5 Poultry Vaccines Tested Appear Effective Against H5N1) found many older poultry vaccines (still in use) were not up to the task.
But with the clock ticking, you don't always have the luxury of waiting for the perfect solution.
As scavengers, Condors feed almost exclusively on carrion, which not only exposes them to toxins and lead, it presumably increases their risk of being exposed to (potentially mammalian-adapted) HPAI H5 viruses (see USDA Mammalian HPAI Infection List).
Forty years ago California Condors were nearly extinct, but due to conservation efforts by the US Fish & Wildlife Service, the National Park Service, and breeding programs at San Diego's Wild Animal Park and the Los Angeles Zoo, that species was granted a reprieve.
Hopefully they'll be equally successful against this latest threat to the Condor's survival.
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