The Conversation: Vaccines have health effects beyond protecting against target diseases
Christine Stabell Benn, professor of global health at the University of Southern Denmark

“…[W]e now have evidence that a vaccine can change the immune response to subsequent unrelated infections in humans. This goes a long way to explaining how vaccines can influence other diseases and overall health. … It is time to change our perception of vaccines: vaccines are not merely a protective tool against a specific disease, they affect the immune system broadly. In the case of live vaccines, the immune system is strengthened. In contrast, non-live vaccines seem to have a negative effect on the immune system in females. … So there is an urgent need for studies testing different sequences of live and non-live vaccines. Studies into the overall health effects of vaccines are providing new insights about the immune system and how it may be trained by vaccines. Live vaccines seem to be potent immune trainers, and with this new knowledge we may be able to reduce global child mortality by more than a million deaths a year. With smarter use of vaccines, we may also be able to reduce disease and improve child health in wealthy countries” (1/11).