Many contemporary vaccines contain auxiliary substances called adjuvants to help improve the efficacy of the vaccine, in part by activating the immune system. Many new adjuvants are currently under development, but scientists do not exactly know yet how they work. The use of an adjuvant may also present a risk of over-activating the immune system. PhD Candidate Susan van Aalst has studied how the choice of an adjuvant in a vaccine can contribute to the success of vaccinations.
There is considerable debate about vaccine safety, and especially about the role played by adjuvants. In her PhD research, Van Aalst studied the mechanisms and safety aspects of certain adjuvants and the vaccines that contain them. She also studied two promising new vaccination methods, via the skin and via the nose. Van Aalst used a mouse model to show that various adjuvants have different biological mechanisms. The choice of which adjuvant to use in a vaccine can therefore make a major difference in the success of the vaccination.
“We also tested two different safety aspects of vaccines using an extremely strong, unsafe adjuvant that is not permitted to be used in humans. The first safety aspect we studied was the effect that the adjuvant had on an important immune cell that keeps the immune system in balance. We also examined if the adjuvant activates immune cells that are not supposed to recognise the vaccine. In both cases, we found no proof that the unsafe adjuvant has an effect on the safety aspects tested. This gives us more confidence in the safety of adjuvants used in vaccines.”
Good protection against pathogens
Additional knowledge on adjuvants, both their modes of action and aspects of immunosafety, will aid in the development of new, improved and safe(r) vaccines that will provide good protection against infectious diseases without any unnecessary side effects.