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A vaccine was developed in the United States to protect bees from a very contagious disease, American foulbrood, responsible for the destruction of hives. But if it represents hope, this vaccine will not respond to all the threats weighing on these insects, according to Cédric Alaux, specialist in bee biology at Inrae.
For the first time, a vaccine has been developed in the United States to protect… bees. While the life expectancy of these insects essential to biodiversity has halved in 50 years, this new vaccine represents hope.
Developed by the American biotechnology company Dalan Animal Health, the vaccine – a serum, more precisely – was approved early January by the US Department of Agriculture. So far limited to the United States, it will relieve beekeepers facing “American foulbrood disease”, a highly contagious deadly condition responsible for the loss of 40% of American hives in 2019.
To understand the openings of this new kind of vaccine, France 24 spoke with Cédric Alaux, researcher at the Avignon bee and environment unit at the National Research Institute for Agriculture, Food and Agriculture. environment (Inrae).
France 24: How does this vaccine work? ?
Cedric Alaux: This is a serum that exposes queens to dead bacteria that cause American foulbrood. Concretely, the future queens will be fed with royal jelly, to which dead bacteria are added. Once ingested, these will go to their ovaries, and allow the eggs to be exposed to this disease early, without being killed. Future workers born to the queen will therefore be prepared for the disease, and better protected, even if it does not work 100%.
This is a first among insects. This is not a classic vaccination, like the one we do for men, where we vaccinate an individual. There, we vaccinate the queen, who will then transmit the protection to her offspring, because the foulbrood disease primarily affects the larvae. It is therefore fundamental, beyond the queen alone, to protect the larvae and the future workers.
Does this vaccine have any use outside the United States, or does it above all open up new avenues for research?
Highly present in the United States, American foulbrood disease is less present in Europe and France, although there are cases worldwide. Rather, I see new research perspectives in this vaccine, because a very important step has been taken.
We will of course have to see what this will give, but the operation of this vaccine could be applied to other diseases. Bees are affected by a whole cohort of viruses, including that of “deformed wings”, carried by the Varroa mite. It is a small parasite which feeds on young bees, and which, like mosquitoes on humans, transmits a virus to them. This virus produces malformations and drastically reduces the longevity and performance of bees. It is very prevalent in France, where it represents one of the main factors in the decline of colonies, and even, with climate change, the number one problem for beekeepers.
We protect ourselves for the moment by applying acaricide in the hives, but it is a chemical treatment, against which resistance eventually develops. If this new vaccine could work against the virus, as it works there against a bacterium, it could be an alternative or a complement to protect hives.
So does this new type of treatment represent great hope for the survival of bees?
Let’s say it’s a plus, but not a miracle solution. The vaccine alone will not solve the problem of dwindling bees, which is caused by a multiplicity of factors. Bees suffer from exposure to pesticides, such as neonicotinoids, and from the decrease in floral resources, which are increasingly rare and less and less diversified. This decrease has an impact on the development and health of the colonies, the bees eat less, and less of different things. All this is further exacerbated by global warming, because plants produce less and less nectar and less and less rich pollen, which again affects bees.
But diseases still play a very important role in the decline in the number of honey bees. Beekeepers are finding it increasingly difficult to maintain their populations. If we manage to develop new treatments against diseases, like this first vaccine, this will necessarily relieve beekeepers, saving them a lot of losses.
On the other hand, this will probably not work for wild bees, which are the most threatened. Solitary, they are much more sensitive to environmental pressures, and it is not a vaccine that can help fight against their decline.
