Honeybee vaccine receives conditional license from USDA

American foulbrood is a widespread and devastating disease of the larvae of honeybees caused by the spore-forming bacterium Paenibacillus larvae. To date, the only treatments have been administration of antimicrobials or destruction of the affected honeybee colony.

On Jan. 4, Dalan Animal Health Inc. of Athens, Georgia, which focuses on honeybee health, announced that the U.S. Department of Agriculture has granted a conditional license for the company’s vaccine to protect honeybees against the disease.

In the announcement from Dalan Animal Health, CEO Annette Kleiser, PhD, said: “We are committed to providing innovative solutions to protect our pollinators and promote sustainable agriculture. Global population growth and changing climates will increase the importance of honeybee pollination to secure our food supply. Our vaccine is a breakthrough in protecting honeybees. We are ready to change how we care for insects, impacting food production on a global scale.”

A beekeeper uses a flashlight while inspecting a honey frame for signs of American foulbrood.

The new vaccine, which contains killed whole-cell P larvae bacteria, was developed by Dalan Animal Health and is manufactured by Diamond Animal Health of Des Moines, Iowa, a wholly owned subsidiary of Heska Corp.

According to a USDA notice about the issuance of the conditional license (PDF), federal regulations provide that a conditional license for a veterinary biological product may be issued to meet a special circumstance, in this case disease in honeybees caused by P larvae.

“Conditionally licensed products are required to be pure and safe, and have a reasonable expectation of efficacy,” according to the notice. “This conditional license was issued on the basis that the licensee has demonstrated that the product has a reasonable expectation of efficacy.”

The USDA Animal and Plant Health Inspection Service will evaluate progress throughout the next year. The conditional license expires in two years.

According to the announcement from Dalan Animal Health, the company will distribute the vaccine on a limited basis to commercial beekeepers and anticipates having the vaccine available for purchase in the United States this year.

Efficacy studies indicated that oral vaccination of honeybees may reduce death of larvae associated with American foulbrood caused by P larvae, according to Dalan Animal Health.

The vaccine is administered by mixing it into queen feed consumed by worker bees. The vaccine is incorporated into the royal jelly by the worker bees, who then feed the royal jelly to the queen. She ingests it, and fragments of the vaccine are deposited in her ovaries. The developing honeybee larvae, having been exposed to the vaccine, have immunity as they hatch.

The AVMA provides resources to help increase veterinarians’ knowledge of honeybee medicine.