DSHS’s Annual Oral Rabies Vaccine Bait Airdrop Marks 30 Years

News Release
News Release
January 8, 2024

This month marks the 30th anniversary of the Texas Department of State Health Services’ Oral Rabies Vaccination Program in South Texas, with airdrop flights kicking off Tuesday, Jan. 9 from Edinburg in Hidalgo County. The program has successfully controlled and prevented domestic dog/coyote variant rabies and gray fox variant rabies infections among wildlife, livestock and people.

“Our goal is to vaccinate coyotes and gray foxes along the border to maintain herd immunity against rabies and keep new or previously eliminated rabies variants from becoming established in Texas,” said Kathy Parker, ORVP project director. “We will be distributing vaccine baits over 18 border counties this year.”

This year’s ORVP is expected to last two weeks with additional flights launching from Del Rio on Jan. 15 and from Alpine on Jan. 21. Four aircraft and one helicopter will be deployed for the drop with 8-16 flights likely per day at 500 to 1,000 feet above the ground. Vaccine baits are dropped along half mile intervals, and more than 820,000 oral vaccine rabies baits will be dropped at 64-70 baits per square mile.  

The bait, which resembles a fast-food ketchup package, includes vaccine wrapped in a plastic packet that is dipped in fish oil and coated with fish-meal crumbles to attract target wildlife. The vaccine has been proven safe when given to more than 60 species of mammals and birds.

The program costs approximately $2 million and is funded by the State of Texas and the U.S. Department of Agriculture.

Prior to the ORVP, there had been human deaths in Texas due to canine rabies, and many people in the epizootic area had to receive postexposure rabies treatment. But the ORVP has proven effective over the last three decades. The first ORVP bait drop took place in 1995 in South Texas to control an outbreak caused by a domestic dog/coyote variant of the rabies virus. The number of animal rabies cases caused by this variant dropped from 122 cases in 1994 – the year before the first drop – to zero cases by the year 2000.

The first vaccine airdrop in West-Central Texas targeting the Texas fox (grey fox) rabies virus variant took place in 1996. The number of animal cases caused by this variant decreased from 244 cases in 1995 to zero cases by May 2009. A cow was identified in 2013 as being infected with the gray fox rabies variant, and the ORVP contingency response was to include vaccine baits in the 2,500 square-mile area around the case in 2013, 2014 and 2015. No additional rabies cases attributed to the gray fox variant have been identified in Texas since then.

There have been no human cases of rabies attributable to any of these rabies variants since the ORVP began.

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(News Media Contact: pressofficer@dshs.texas.gov)