Double agents

Looking at a vial of liquid or a solid pill, it’s easy to see pharmaceuticals as simple objects rather than a complex array of chemicals and raw materials, delicately balanced to achieve a desired effect. The current coronavirus vaccines are a good example of such a balance, with the list of ingredients including water, sugar and salt, all of which play a different role in the effective deployment of the messenger RNA (mRNA) that stimulates the immune response. But one category of components has held the spotlight recently for its ability to improve the protection offered by vaccines. Monica Karpinski looks at the role adjuvants play in making vaccines effective, as well as the research that suggests they could hold even greater unrealised potential.