As awareness surrounding disease rises, and an anti-vaccination movement grows, researchers find more evidence of the importance behind measles vaccination; immune amnesia.
Prior to mass vaccination in the year 1960, the United States saw 500,000 infections and 650 children die of measles every year. 95% of all children would contract measles before the age of 15. As it turns out there may have been many more deaths due to measles than previously known. After mass measles vaccination it wasn’t only measles deaths that had decreased, but so did death by pneumonia, diarrhoeal diseases, and meningitis.
Since correlation isn’t necessarily causation, let’s backpedal through this story a bit.
Immune amnesia
Researchers studying how measles affected the immune systems of monkeys found T cell health was relatively unaffected by measles but B cells had taken a major blow. B cells are a kind of lymphocyte, a white blood cell, which secretes many antibodies such as memory B cells. They hold onto instructions for how to fight specific foreign pathogens. After the measles attack, it could take months or years for them to recover.
“The high incidence of respiratory and gastro-intestinal complications following measles [1]–[3] may therefore be directly related to the observed high percentages of MV-infection and subsequent lymphocyte depletion in the adenoids, tonsils and gut-associated lymphoid tissue, which form a first line of defense against inhaled or ingested pathogens. We conclude that MV infection wipes immunological memory, resulting in increased susceptibility to commensal or opportunistic infections.” – Measles Immune Suppression: Lessons from the Macaque Model
An immune system without one of its specialists means an entire library for protecting the body is missing; immune amnesia. The irony of this situation is immune amnesia didn’t apply to the measles, those memory cells were retained and amplified.
A recent study in Science has shown that 11 to 73% of already developed antibodies are entirely wiped out. In the first 3 to 10 days alone 20 to 70% of memory and plasma cells are infected. This means potentially losing the ability to protect yourself from anything you’ve been immune to before. Potentially, you may even lose gained immunity from vaccines you’ve had!
Who, in their right mind, would want to get chickenpox for a second time?!
A bit more science
In its heyday, prior to the vaccine, measles had infected nearly all children and killed at least 2.6 million people yearly across the globe. It is probable that half of all childhood deaths at that time could be attributed to measles. It is not difficult to imagine just how dangerous immune amnesia can be for a child.
Part of this research was made possible by a new technology called VirScan. With a single drop of blood, it can detect any antibodies present in a person’s body from all of its previous encounters with bacteria and viruses.
Measles outbreaks have struck the Netherlands in recent years and researchers used VirScan to study blood samples from the patients. Their data was able to transform the hypothesis; measles had in fact caused immune amnesia in children who weren’t vaccinated against it. They found it could take up to 2 years for the immune system to recover.
B lymphocytes and antibodies diagram
Don’t contract immune amnesia
Measles was a serious pandemic at one time. With more in-depth knowledge about cell function we now grasp an understanding of precisely why measles is so serious. Contracting measles may provide immunity to the measles but it destroys the ability to fight off even the simplest of viral or bacterial infections. A mother may pass on some antibodies to their child but measles will actually erase them.
To this day, people around the world still die because of measles infection. A disease that was once thought to be eradicated. It stands to reason, then, that receiving a vaccination against measles is beneficial for a person’s overall health, as well as the health of the people around them.
