News of a vaccine to protect bees from American Foulbrood disease has received a cautious welcome from a New Zealand expert.
United states bio-tech firm Dalan Animal Health has been granted a conditional licence for a vaccine to combat AFB, administered through a colony’s queen bee.
The vaccine works by incorporating the disease’s bacteria into the “royal jelly” that worker bees feed to the queen bee. She in turn passes it through to her larvae that develop an immunity to AFB as they hatch.
The company has claimed reductions in hive mortality rates of 28-50% from a disease that currently has no known cure and is found throughout the world with the exception of the Chatham Islands.
In NZ the disease initially devastated early beehives, wiping out 70% of the country’s production in the late 1800s. Today disease levels are low at between 0.26 and 0.31%, but the outcome for any infected hive is complete collapse.
Clifton King, compliance manager for NZ’s AFB pest management plan, is cautious about how effective the vaccine may yet prove to be, although “the fact that there is even a vaccine out there is an exciting development”.
“Having read through the safety and efficacy report the company published for USDA approval, it appears the vaccine results in a reduction in bee larvae mortality of 28-50%, but there is a ‘but’,” King said.
“Reducing the number of larvae that die is not the same as stopping the infection. [Fewer] larvae died, but it looks like the hives are just slower to die.”
Slowing the rate of spread could be problematic in that it could take beekeepers longer to diagnose AFB infection in hives, and also give it more time to spread to other hives via infected bees – “and in NZ what really matters is the spread of AFB from hive to hive”.
“But the paper gives no indication either way of that effect, and being a conditional licence means there is more research to be done,” King said.
However, he said it is exciting that there is a vaccine in play for such a disease and over time a better understanding of its full effect will hopefully reveal itself.
On its website Dalan Animal Health cites a development pipeline that includes pre-clinical trials for European Foulbrood vaccine. At present NZ does not have European Foulbrood in hives.
