The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) 5th Vaccine Conference will cover the risks of failing to vaccinate children for measles.
Measles, a contagious infectious disease, can cause fever, rash and other symptoms in most children and complications including pneumonia and brain inflammation. In 2018, across the globe measles killed approximately 1 in every 75 children infected with the virus, leading to over 100,000 deaths.
Furthermore, research by assistant professor Michael Mina, MD, of Center for Communicable Disease Dynamics at the Harvard T.H. Chan School of Public Health and Harvard Medical School, and colleagues from his own and other groups suggests that infection with measles in unvaccinated children increases their risk of other, subsequent severe, non-measles infectious diseases in the 2-3 years following infection. Thus, after surviving measles, children may fall ill or die from other infections which they previously developed immunity to, but this immunity was erased by the measles virus.
This observation, backed by numerous studies (with the mechanism still being investigated) shows that when measles virus infects a person, it primarily infects a large proportion of the memory cells of the immune system. This results in so called immune-amnesia, whereby the immune system cannot remember some of the diseases it has fought in the past, thus exposing children to re-infection with these other diseases.
These findings would help explain the mysterious large drops in mortality of up to 50% following the introduction of measles vaccinations, even though prior to vaccines measles was usually associated with much less than 50% of childhood deaths.
“Prior to vaccination, measles infected nearly everyone. Because we now think that measles infections may erase pre-existing immune memory, by preventing measles infection through vaccination, we prevent future infection with other infectious diseases allowed back into the body by the damage done by measles,” explains Mina. “The epidemiological data from the UK, USA and Denmark shows that measles causes children to be at a heightened risk of infectious disease mortality from other non-measles infections for approximately 2-3 years.”