No, the title of this post doesn’t mean I’ve posted before about the measles vaccine. In fact, I’ve never said anything about measles or the vaccine in these little essays on WordPress. What I’m saying here is that this posting is about a second reason for getting the vaccine, if you or your children aren’t presently vaccinated. The primary reason for getting the vaccine is two-fold: to prevent getting the disease caused by the wild virus, and, by extension, to prevent spreading the disease to others. It is this main reason that measles and the measles vaccine have been in the news so much lately. But there is also a second reason to get vaccinated. This has to do with infants and their mothers.
Before the measles vaccine was developed, measles was a common childhood disease, along with mumps, chickenpox and rubella. (All of those also have vaccines, by the way.) There were millions of cases of measles every year in the US. There were very few deaths due to measles, but what is most important for this discussion is that girls and women who got the disease also got a life-long immunity to it. When these women got pregnant, they passed some of their immunity to the developing fetus, and this immunity helped keep the newborn from contracting the disease for a short time after birth. An infant’s immune system is not fully developed until about nine to twelve months after birth, and this is why the recommendation is that a child not get his/her first immunizations until he/she is about one year old. Well, Mother Nature, in her infinite wisdom, took care of that delay in immune system formation and allowed some of the antibodies that the mother possesses after a natural infection to cross the placenta and circulate in the newborn’s blood. That way the infant was protected. Well, to a certain extant. This type of transferred immunity isn’t as good as that after a natural infection, but it is something.
Then, along came the vaccine. Since the measles vaccine was introduced in the early 1970’s, the number of new cases of measles has dropped drastically. Now, here in the early twenty-first century, we see very few cases. But mothers now don’t have that immunity induced by a case of the measles, so they don’t pass it along to their children. Now we’re beginning to see cases of measles in children under one year old. And these cases can be severe. When the child had transferred immunity, if he/she did get infected, the disease was frequently milder.
So now we have a rather un-natural situation. The vaccine reduced the disease, but it left young women with little or no immunity. So, it is incumbent on all of us to get the vaccine to help prevent infections that might be transferred to a totally unprotected newborn. Young women who expect to become pregnant soon are advised to get the vaccine, even if they had the vaccine as a child. But this is more to help prevent them from transmitting the virus to their newborns, not to boost their immunity. Vaccinated mothers probably don’t transfer much immunity to their fetus, at least not as much as a natural infection would.
The only way out of this situation is to eradicate the disease from the face of the earth, as has been done with smallpox. Measles is a good candidate for eradication, too. Only in that situation can a young mother be sure her infant won’t get measles. For whatever reason.
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