A first vaccine for bees raises hope

The invention of a first vaccine intended for honey bees raises hope among beekeepers in Quebec, who have to deal, year after year, with considerable mortalities within their apiaries.

In early January, the United States Department of Agriculture (USDA) issued conditional approval for the use of a vaccine to combat American foulbrood, a virulent bacterial disease.

Dalan Animal Health – which will start by distributing the vaccine south of the border on a limited basis – told The Press that it would take steps “as quickly as possible” to have the product accredited in Canada.

“We began discussions with the Canadian Food Inspection Agency (CFIA) Canadian Center for Veterinary Biologics last year with our manufacturing partner in the United States,” the American company said in a statement. written statement. “Now that we have entered the US market, we can start the process for CFIA approval,” she added.

“Devastating”

American foulbrood is a highly contagious disease caused by Paenibacillus larvae. It infects the larvae of honey bees from the first days after hatching.

“It’s a bacterium that has been causing a devastating disease in hives for 100 years,” explains Pierre Giovenazzo, professor of bee science at Laval University. “It’s a bacterium that makes spores that resist virtually all sterilization treatments,” he adds.

The vaccine, which contains the dead bacteria, is administered in the food of the worker bees, which will then incorporate it into the royal jelly.

When the queen eats the jelly, fragments of the vaccine end up in her ovaries. Since they have been exposed to the vaccine, the larvae develop immunity against the disease.

Laboratory tests have shown that larval mortality could be reduced by 30 to 50% after vaccination of queens, reports an article published in October 2022 in the scholarly journal Frontiers in Veterinary Science.

“The transmission of immunity from the queen to the babies […]it’s really interesting”, emphasizes Professor Giovenazzo.

Burn the beehives

In 2020, the Ministry of Agriculture, Fisheries and Food of Quebec (MAPAQ) analyzed 119 samples taken from hives. As a result of this analysis, seven companies have received a positive diagnosis of the disease.

According to MAPAQ, the bacterium can survive more than 40 years in the environment in a so-called sporulating form. To get rid of them for good, beekeepers usually choose to burn their hives.

“Even if you use antibiotic treatments, you will hide the symptom, but the disease is still there,” explains the president of the Apiculteurs et apicultrices du Québec, Raphaël Vacher.

Bee larvae are white. “As soon as you start having American foulbrood, their color changes, they become yellowish or brownish. It stinks, too, it smells like rotten eggs. The brood becomes disgusting”, describes Mr. Vanier.

All over the world, beekeepers are complaining that their bee colonies are collapsing. Several causes are singled out, such as climate change and the use of pesticides.

But it is the “varroa destructor”, caused by a species of parasitic mites which was introduced in Quebec in the 1990s, which is above all responsible. In the spring of 2022, varroa caused losses of historic magnitude in Quebec, with an average winter mortality of 60%.

Enthusiasm among beekeepers

Although American foulbrood is not the main cause of colony collapse in Quebec, the tool is enthusiastically welcomed by beekeepers in Quebec.

“I’m super happy to see that, for the first time, there can be a vaccine for bees,” says Vacher. A hive sometimes finds itself with two, three or four diseases to manage at the same time. It is certain that if we eliminate the foulbrood, listen, it is certain that there, we have just given ourselves a 20-25% more chance. »

Pierre Giovenazzo agrees. “Bees have almost over twenty different viruses that we can’t treat, so that opens the door, maybe, for [le développement] antiviral treatments. »

It is difficult to know if – and in how long – the vaccine could be authorized in Canada, since the federal agency limited itself to saying that “for reasons of confidentiality, the CFIA cannot disclose whether a manufacturer, including including Dalan Animal Health, submitted a product request or not”.