According to scientists, bees vaccinate their offspring by naturally immunizing them against some diseases that are found in their environments. A bee blood protein, vitellogenin has been analyzed by researchers from University of Helsinki, Arizona State University, University of Jyvaskyla and Norwegian University of Life Sciences.

It has been found by researchers that this protein contributes a lot in providing protection to bee offspring against disease. According to Gro Amdam, a professor with ASU's School of Life Sciences, "The process by which bees transfer immunity to their babies was a big mystery until now. What we found is that it's as simple as eating. Our amazing discovery was made possible because of 15 years of basic research on vitellogenin".

The queen hardly leaves the nest in a honey bee colony, therefore worker bees have to bring food to her. Forager bees can carry pathogens in the environment, while collecting pollen and nectar.

Worker bees use the same pollen in order to create "royal jelly", which is a food produced only for the queen that consists of bacteria from the external environment. The bacteria are digested in the gut following their consumption, and then they are transferred to the body cavity and are stored in "fat body" of the queen.

After that, pieces of the bacteria are bound to vitellogenin and carried through blood to the developing eggs. As a result of this, bee babies are immunized and their immune systems are prepared in a better way to fight diseases found in their environment.