Dr's Casebook: Another reason to protect against measles

Dr Keith Souter writes: At that time our practice was one of two sentinel practices in Yorkshire for the research unit of the Royal College of General Practitioners. We sent weekly statistics on infectious diseases to the unit for analysis and flagged up when outbreaks of infections were starting. I mention this because when we had outbreaks of measles, we also found that many children seemed more prone to get other infectious diseases soon after.

Research from the Wellcome Sanger Institute in England and the University of Amsterdam in the Netherlands discovered why this happens. Effectively, the measles can wipe out the immune system’s memory, making a person more vulnerable to other diseases. This is really important, because the national decline in immunisation is resulting in a measles comeback, which has been widely reported in the media.

During a measles infection, a person has fewer protective white blood cells. It takes a few weeks after recovery for those white cell numbers to increase again. The trouble is that even though those numbers rise back to normal, the person is still more susceptible to other infections.

Researchers looked at a group of non-vaccinated people in the Netherlands, taken before and after a 2013 measles outbreak in a community. By sequencing antibody genes from children before their infection and then 40 to 50 days after their infection, they found that specific immune memory cells built up against other diseases, which were present before the measles infection, vanished from the children’s blood at 40 days. In other words, the measles virus wiped out the immunity that they had to other diseases before the measles episode.

After further animal research they concluded that measles resets the immune system to an immature state, where it is only able to make a limited number of antibodies.

So, measles vaccination not only prevents measles, but it keeps the immune system’s memory active to protect against other infections. Even more reason to get protected.