Decades after an effective vaccine helped wipe smallpox off the face of the earth, researchers claim they finally understand how that injection induces immunity: by recruiting bacteria found on the skin.
Smallpox vaccination involved pricking the skin with a needle to introduce live vaccinia virus. The vaccine, which is no longer in use, was crucial in the global eradication of the disease in 1980 but, until now, scientists didn’t know how it worked. In a new study published in PLOS Pathogens on April 21, researchers from the University of Cambridge in the UK and the University of Bern in Switzerland found in mice that local skin bacteria introduced into the vaccination site may play a role in bolstering the host’s immune response.
In the study, the researchers vaccinated three groups of mice with the vaccinia virus and compared their immune responses. The first group included seven-week-old specific-pathogen-free (SPF) mice (laboratory ...
