1 Research Center for Vitamins and Vaccines, Statens Serum Institute, Copenhagen, Denmark; 2 University of Southern Denmark, Odense, Denmark; 3 Bandim Health Project, Bissau, Guinea-Bissau
Can a measles vaccine protect you from pneumonia? Can a tuberculosis vaccine protect you from blood poisoning? Was smallpox vaccine the best preventive measure against AIDS that mankind ever had? And are these effects different for men and women? The speaker will argue that the answer to all these questions is yes. Her group’s research on vaccines in the world’s poorest countries have provided insight into the vaccines multifaceted effects.
Research results show that in addition to their ability to protect against a specific disease, vaccines also have so-called non-specific effects. The live attenuated vaccines, which contain a bit of the live disease organism in a weakened form, appear to boost the immune system’s ability to protect itself against other disease organisms. However, the non-live vaccines, which contain a bit of the dead disease organism, seem to reduce the immune system’s ability to defend itself against other pathogens, particularly among women.
These findings are controversial and create a lot of opposition, mainly from the point of view that these non-specific effects of vaccines are “biologically implausible”. However, emerging immunological studies support that the immune system may learn from one incident and use the experience to generate a response to unrelated incidents – just like the brain.
If vaccines have non-specific effects and modulate the immune system in hitherto unappreciated ways, it has implications for basic science as well as for public health. Immunization programs designed to take into account and optimise both specific and non-specific effects of vaccines hold the potential for greatly improving health in both low-income and high-income settings.