Although we don’t really need another reason to convince people to get their measles vaccination, scientists have nevertheless found one. As it turns out, the measles vaccine protects you from more than just the the measles. For years, scientists have known that the virus is able to suppress our body’s immune system, even months after the infection has cleared. As a result, measles patients are especially vulnerable to secondary infections such as pneumonia, which can lead to death.
Yet, Michael Mina of Princeton University recently found that there’s much more to this story than just secondary infections. All you have to do is look back at the data collected on the number of deaths caused by various infectious diseases over the years. Of course, when the US began vaccinating children against the measles in the 1960’s, the number of measles-related deaths plummeted. Surprisingly though, there was also a sharp drop in the number of deaths due to other infectious diseases as well.
Now, as Michaeleen Doucleff of NPR rightly points out, the reduction in deaths could be related to improvements in the overall quality of healthcare over time. However, this same phenomenon also occurs in almost every other country that has introduced the measles vaccine. Furthermore, Dr. Mina points out that “In some developing countries, where infectious diseases [rates] are very high, the reduction in mortality has been up to 80 percent.”
So what exactly is going on here?
Previously, scientists have found that the measles not only is able to suppress our immune system, it is also capable of wiping our immune system’s memory clean. For example, normal people who contract the chicken pox will never get it again in their lifetime because their body knows how to fight it off. It does so by producing cells (memory T cells, to be exact) whose specific job is to attack any invader that looks like the chicken pox. For people who have also had the measles, this is no longer true as those cells get destroyed during the infection. Essentially, contracting the measles pushes the reset button on your immune system.
While Dr. Mina provides compelling evidence to support his hypothesis (coined the “immune amnesia” hypothesis), like all things in science we can’t take this to be true until we perform ten million redundant experiments showing that he is right. However, there is one thing that we can take away from this hypothesis, and it’s the same thing we’ve been saying for years:
For goodness sake, vaccinate your damn kids!