Vaccinating honey bees

Many WVBA members probably saw the news about the development of a honey bee vaccine to protect colonies from American foulbrood. The most recent good news was that the USDA has issued a conditional license for two years for vaccine use. The vaccine, PrimeBEE, should be available for purchase in 2023. And additional good news is that it will not be necessary to give a vaccine shot to every bee in the hive- only the queen will get the vaccine.


Dalan Animal Health, a small biotech firm (<10 employees), will distribute the vaccine, though it will be manufactured by Diamond Animal Health of Des Moines, IA. Dr Annette Kleiser   Dalan CEO (,  states the Dalan mission is to “seek to prevent diseases that affect beneficial insect populations to increase the profitability and yield of pollinated crop farms worldwide.”  The company plans to expand following release of their initial vaccine product to develop vaccines for other honey bee diseases, as well as underserved industries, such as shrimp, mealworms, and grasshoppers used in feed and food production.

Newer WVBA beekeepers may not be aware but prior to Varroa mites, American foulbrood (AFB) was the major health concern for keeping healthy honey bees. The youngest honey bee larva that happen to ingest enough AFB bacterium Paenibacillus larvae, via their worker jelly, can subsequently incubate the bacteria in their gut. The bacteria quickly multiply, then escape the digestive tract to be transported via bee hemolymph to developing body tissues, killing the larva from the inside. Before larvae die, the bacteria forms spores that pass to pre-nurse age cleaning bees that come in to clean up the diseased larvae and their beeswax comb cells. These bees then pass the bacterial spores to infect additional larvae once they become nurse bees. At some point the bees can’t control the disease and the colony spirals downhill.

During the late 1800s and early 1900s, the disease devastated bee colonies in parts of the United States. The threat was so serious that states passed bee disease laws regulating AFB. Legislation allowed bee inspectors to open and inspect colonies  – those ‘found foul’ were burned immediately, without beekeeper compensation. Beekeepers faced fines and even jail time if they did not comply. There is no current apiary inspection program in Oregon (some WVBA individuals have formed a task force that helps members diagnose bee disease and deadouts).

Currently American foulbrood is considered under far better control than it was a century ago. The AFB spores are common however when honey or bee colonies are examined. But active AFB infestations are not common.  It is thought that bee resistance to AFB and use of antibiotics to mask colony symptoms of the disease by larger-scale beekeepers have helped reduce the incidence of the disease. When resistance was documented to the antibiotic terramycin, beekeepers switched to tylosin, which  is biologically active for an extended time period. Today the antibiotics are only available through a veterinary feed directive or veterinarians’ prescription  (see

The bee vaccine contains an inactivated version of the AFB bacteria Paenibacillus larvae.  In contrast to a human vaccine, the new bee vaccine is not injected via needles into bee bodies. Rather it is mixed into queen candy.  When queens eat the candy, fragments of the bacterium reach her ovaries and then are passed into her eggs. The larvae then have immunity during their earliest instars when the Paenibacillus bacterium is normally most infectious.

Immunity is possible via the eggs a queen produces which carry immunity to the AFB bacterial pathogen fed to the queen. Finnish researchers Dr. Dalial Freitak and Dr. Heli Salmela in 2015 discovered that bacteria will bind to the egg-yolk protein vitellogenin in bees. Their lab tests (using 2 queens) demonstrated they could cultivate immunological memory in a bee population by feeding a deactivated bacteria. A single queen mother can prime her offspring’s immune system via passage to her eggs. See Journal PLOS

Dr Ramesh Sagili was consulted by Popular Science when the news of this development first appeared in the scientific press (Frontiers in Veterinary Science Oct 22).  He reported: “They have shown a proof-of-concept” but cautioned that the data was from “…studies conducted in an isolated, lab-controlled setting” (open field tests with AFB colonies represent possible danger to surrounding bees in other apiaries). He continued “I’m convinced they have something promising here, but only if they do some large-scale field studies – this type of technology has suffered from a lack of success when tested in the field.”

This vaccine is ONLY for the AFB bacterium. It will not work with EFB, although the company plans to do this research. They are confident they can vaccinate bees for this bacterial disease as well. Unfortunately, no vaccine can eradicate mites, the most serious issue we face as beekeepers. It is surmised that perhaps a vaccine might be able to protect honey bees from the viruses associated with the mites, including deformed-wing virus, said Keith S. Delaplane, the director of the Honey Bee Program at the University of Georgia and a consultant to Dalam.  Scientists still have to demonstrate the efficacy of a vaccine to treat those kinds of viruses; developing  a vaccine for a virus will be more difficult than for bacterial pathogens.

Will we soon have option of purchasing AFB vaccinated queens? It holds promise as a valuable addition to our keeping healthy honey bee colonies.