Scientists at the University of Helsinki have developed a new edible vaccine to help honeybees stave off potentially deadly bacterial infections. This is the very first "inoculation" designed specifically for insects.
Honey bees have a lot to contend with, from pesticides to habitat loss, climate change, and disease. American foulbrood (AFB) is a particularly nasty bacterial infection that has been known to wipe out entire colonies.
Paenibacillus larvae is the spore-forming bacterium responsible for AFB. It is usually introduced to the colony via a nurse bee who delivers spore-contaminated food to the larvae. The spores germinate in the larvae's stomach, where they multiply and spread until they kill the fledgling bee – at which point, they go on to infect their next victim. Spores can remain viable for a long time and continue to re-infect the colony years after the initial infection.
This new vaccine (called PrimeBEE) is designed to be delivered to the queen bee via a sugar patty. Alternatively, NPR reports, beekeepers may be able to order a queen that has already been vaccinated. The idea is that immunization will pass from generation to generation, starting with the queen. Over time, the entire colony will gain immunity.
How exactly? According to the university's press release, if the queen eats something containing pathogens, those pathogens are bounded by a protein called vitellogenin. That protein then transfers the pathogen's signature molecules to her eggs, protecting offspring from future infections like a vaccination.
The vaccine is still in the testing phases so it is too early to guarantee an unequivocal success. There is no information yet on when it will be available to purchase – or how much it will cost. But if the researchers are correct, the implications could be ground-breaking.
"Now we've discovered the mechanism to show that you can actually vaccinate them. You can transfer a signal from one generation to another," Dalial Freitak, a researcher involved in the project said in a statement.
Until recently, experts doubted the possibility that a vaccine for insects could exist – ever. Unlike mammals, insects do not have antibodies, a key facet for immunization. Fortunately, there is a loophole, first identified by Freitak in moths. In previous research, Freitak observed that individuals showed a better immune response if their parent had been exposed to the bacteria in their food.
It was not until she heard a talk by Heli Salmela that she suspected vitellogenin could be the mechanism behind this immunity. The pair worked on a study published in 2015 that revealed the process by which honey bees pass on immunity to certain diseases to their offspring. Clue: it involves vitellogenin.
So, what's next? "We hope that we can also develop a vaccination against other infections, such as European foulbrood and fungal diseases," Freitak continued.
"We have already started initial tests. The plan is to be able to vaccinate against any microbe"
