Katie Flanagan
MRC Laboratories, Tasmania
Title: Non-targeted effects of childhood vaccines: epidemiological evidence and emerging immunological mechanisms
Biography
Biography: Katie Flanagan
Abstract
It is now recognised that vaccines administered in infancy can have non-targeted or heterologous effects on the immune system and alter susceptibility to non-vaccine related infections. In the case of BCG and measles vaccines these effects are beneficial leading to decreased susceptibility to infections; while for other vaccines such as the diphtheria, tetanus, pertussis vaccine (DTP) these can be harmful leading to increased infections and all-cause mortality. Intriguingly, female infants are generally more susceptible to non-targeted effects of vaccines than males. The immunological basis for such non-targeted effects are beginning to be teased out, and are likely multifactorial. For BCG vaccination, it has been shown that the vaccine can have epigenetic effects leading to enhanced innate immunity; while DTP vaccine can suppress innate and T cell immunity. The reasons for sex differences include the effects of sex hormones, X- and Y-linked immune response genes and microRNAs. This talk will discuss the epidemiological and immunological evidence for non-targeted effects of vaccines, and describe newly emerging data that support sex-differential heterologous effects of DTP and measles vaccination in infants.