Termite Vaccination Programme
Humans aren't the only ones with a vaccination programme, apparently. James Traniello and his team at Boston University in the US have found that termites vaccinate their nest-mates, protecting them against diseases that, unchecked, would wipe out their colony. Other social-animals have similar strategies for controlling infections within their numbers. For instance ants remove dead workers from their nests, whilst bees increase the temperature in parts of their hives infected with fungi to stop the invading organism from growing properly. So what do the termites do ? The Boston scientists have found that if they infected some termites with a fungal disease, allowed them to recover, and then introduced them to a group of termites that had never had the fungal disease, these new 'unexposed' termites fared much better than termites that had not previously mixed with survivors of the disease. The team are calling this 'social vaccination', although they are not sure how the termites are sharing immunity to the infection amongst their nest mates. Termites regularly share gut-bacteria with each other to enable them to digest food, so they could be sharing strains of bacteria that naturally make fungicides. Alternatively, immunised termites might be passing dead fungal 'spores' to each other, so that they can experience the infection safely, rather like injecting dead viruses or bacteria into a person to make them immune.