Vaccine for honeybees: a new hope for American foulbrood disease

Vaccine for honeybees from Dalan Animal Health

In the last few years, there has been an ongoing movement to ‘save the bees’, and the U.S. biotech Dalan Animal Health is playing its part in doing just that, having created a vaccine for honeybees to protect them from the destructive and fatal effects of American foulbrood (AFB). 

AFB is an infectious bacterial brood disease caused by the spore-forming bacterium Paenibacillus larvae, and is one of the most widespread and devastating bee diseases around, wreaking havoc on hives. It gets its name from the foul odor that the larvae emit when infected – a sign easily recognizable to beekeepers. 

In the initial stages of AFB, only a few dead larvae or pupae may appear, and it can either advance to a critical stage rapidly, or take until the following year. Either way, the disease is highly contagious, with the robust bacterial spores able to remain viable for decades after infection, spreading easily between hives and apiaries. 

Generally, transmission occurs due to certain beekeeping practices, such as through the exchange of equipment and transfer of combs and brood from an infected hive to a healthy one. Adult bees, which are not affected by AFB, can also transmit the disease, through robbing – in which bees steal honey or nectar from infected colonies – or drifting – where bees drift from one hive to another. 

And, not only is the disease fatal for the honeybees, it also has a grievous financial impact on beekeepers; once a hive presents clinical symptoms of AFB, beekeepers must burn and bury the hive, colony and all related equipment deep in the ground. The lost annual revenue of doing so – due to AFB and other diseases – is estimated to be $400 million. Therefore, the situation for beekeepers is extremely precarious, particularly given that the disease-causing bacteria are present in an estimated 50% of commercial hives worldwide, and can erupt at any time. 

However, there is now a new hope for the prevention of foulbrood disease – which has traditionally been treated using antibiotics – after the world’s first vaccine for honeybees, developed by Dalan Animal Health, received a conditional license from the U.S. Department of Agriculture (USDA) earlier this year. 

The world’s first vaccine for honeybees: a preventative measure

A vaccine for honeybees, or any kind of insect, may seem somewhat implausible – after all, it’s hard to imagine trying to inject masses of tiny creatures – but, fortunately, there are no needles involved in Dalan Animal Health’s vaccine, and it only has to be given to the queen bee, making the administration process simpler and less time-consuming than one may have initially imagined. 

Instead of being injected, it is administered orally, mixed into the royal jelly fed by worker bees to the queen, after which pieces of the vaccine are deposited in the queen bee’s ovaries. “Her eggs are exposed to the vaccine, which works to induce a future immune response to the pathogen. This allows her offspring to have greater immunity to the disease as they hatch,” explained Dalan Animal Health.  

The vaccine works through transgenerational immune priming, a biological mechanism whereby the maternal animal passes immune modulators, such as antigens and antimicrobial molecules, to the next generation larvae before they hatch. In this case, the vaccine contains killed whole-cell P. larvae bacteria. 

According to the company, the technology behind the vaccine came from academic research done at the University of Helsinki in Finland, which at the time impressed chief executive officer (CEO) of Dalan Animal Health, Annette Kleiser, leading her to partner with one of the researchers, Dalial Freitak, and create a company to bring the vaccine to the marketplace. 

“I was just blown away. I said, ‘Somebody has to do this.’ We all know it’s a big problem. Bees are dying, and while there are many reasons why they’re dying, disease is a major factor. They are livestock, and we depend on them for our food. We’re not going to address pesticides or monocultures any time soon – those are policy decisions – but we know vaccines work and this research has shown it seems to work in bees. This is something we can do now. We don’t have to wait 20 years,” said Kleiser. 

In pivotal efficacy studies, the vaccine was found to reduce larval death associated with AFB by 30 to 50%, which – although the numbers might not sound that high – is enough to stop the disease from manifesting in hives. 

And perhaps one of the best parts about the vaccine, especially when considering the broader environmental theme that surrounds the movement to save the bees, is that it is actually sustainable. Studies found that it has no negative impact on honey, plus it is chemical free, non-GMO and organic. 

Dalan Animal Health will begin distributing the vaccine on a limited basis to commercial beekeepers in the U.S. in spring 2023, whereby beekeepers will be able to request a quote and order the product by visiting Dalan’s website. 

Eliminating the need for antibiotics

Antibiotics have been used by beekeepers to treat and control AFB for decades. However, just like with humans, the heavy use of antibiotics comes with consequences for honeybees, including antibiotic resistance and negative effects on the honeybee microbiome and overall hive health. 

It was for this reason that, in 2017, the U.S. Food and Drug Administration (FDA) started requiring a veterinarian’s prescription or feed directive for the prophylactic use of antibiotics, which largely left the industry without an effective solution for treating AFB.

This makes Dalan’s vaccine even more significant, as it signals a safer, more sustainable solution for treating AFB when compared to antibiotics, plus it can prevent outbreaks before they even occur. 

Moreover, eliminating the use of antibiotics isn’t just beneficial for honeybee health. “I also believe that eliminating the input of these antibiotics into natural systems has to be a good thing for other, non-targeted species that may come in contact with them. Finally, as a consumer, I try to avoid foods that contain antibiotics, so the fact that this product can be used in organic production is a good thing,” commented Clay Bolt, manager of pollinator conservation for World Wildlife Fund-U.S..

As Bolt touched upon with this comment, foods containing antibiotics can impact our own health, meaning that antibiotic residues in honey, for example, can have negative effects on consumers, since the natural biological attributes of honey can be altered.

Saving the bees

Although Dalan’s vaccine offers a new hope in protecting honeybees from AFB, the species are prone to many stressors, including parasites, predators, pesticide poisoning, loss of food due to fire and drought, and bacterial, fungal or viral diseases, which makes finding novel methods of protecting them quite challenging. 

The same goes for wild bees, which are affected by habitat loss, alteration and fragmentation, pesticides, climate change, and a vast array of diseases. 

In any case, however difficult it may be to develop protections for bees, what has become very clear is that protecting them is vitally important. After all, it’s no secret that bee populations are declining, and yet humans and many other species depend on bees, and other pollinators, for survival due to the fact they help pollinate approximately 75% of the world’s flowering plants, as well as around 35% of food crops, such as fruits and vegetables. 

In fact, the U.S. alone is so heavily dependent on managed honeybee colonies for food pollination that hives are routinely taken across the country to propagate different types of crops, from almonds to blueberries. 

Moreover, according to Bolt, protecting bees isn’t just about developing novel treatments for bee diseases, we also need to look at the root cause of why bee populations are declining. 

“There is plenty of research that shows that Neonicotinoid (neonic) pesticides are one of the greatest threats against North American bee populations, and I am not just referring to domesticated western honeybees, but North America’s estimated 4,000 species of native bees too,” said Bolt. 

“A single, neonic coated corn seed contains enough active ingredients to kill an estimated 80,000 bees and nearly all of North America’s 90 million acres of corn is grown from seed treated with these pesticides, whether growers want to use the treatments or not. Neonics have been shown to weaken honeybee immune systems, making them much more susceptible to disease like Nosema apis and pests like the Asian varroa mite. Unfortunately, the pesticide industry has done an excellent job of getting beekeepers to focus on fighting mites, intentionally drawing attention away from the root cause – their products.”

A recent study showed that the impacts of pesticides on bee populations, along with climate change, intensive farming techniques, land-use change and nutritional stress, has resulted in a 3 to 5% reduction in global fruit and vegetable production, as well as an estimated 427,000 excess human deaths.

Bolt referred to Quebec’s model as a potential solution to this problem to be used in the U.S., whereby producers are required to provide justification for neonics use, meaning it won’t leave farmers in a difficult situation, but will prevent the unnecessary use of neonics.

With that being said, Dalan’s vaccine is still a significant step in the right direction in ongoing efforts to try to protect bees, and it could even pave the way for the development of other new vaccines to tackle a variety of the diseases that are known to plague bee populations.

“Our vaccine and platform technology is forging a new insect health sector, changing how we care for honeybees. We are committed to providing innovative solutions to protect pollinators and promote sustainable agriculture. Growing world populations and changing climates will increase the importance of honeybee pollination to secure our food supply,” said Dalan Animal Health.

In fact, Dalan Animal Health is also working on a vaccine to protect bees against European foulbrood (EFB), which is another serious bacterial disease, this time caused by the Melissococcus pluton bacterium. Although less fatal than AFB, it is still highly infectious and is also showing signs of resistance to antibiotic treatment.

And the company’s vaccine platform isn’t just providing hope for honeybees; they also want to develop vaccines for other organisms and diseases.

“This platform technology has the potential to impact many invertebrates, such as mealworms, shrimp, and other insects. More research is needed, but we hope this can be expanded beyond just this disease and organism,” said the company.

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