When I was younger I had measles and so did most of my peers. By the time my children were born, there was a vaccine against measles.
You would think at that point my immune system and those of my children in respect to measles would be the same. That was the case.
However, we have entered a new age. Some parents prefer not to have their children receive the measles vaccine. They feel (incorrectly) that measles is a harmless childhood illness.
That was certainly not true in the 1930s when measles was in the top 10 killers of children.
Antibiotics have made secondary bacterial infections with measles less of a concern than they were then. However, natural measles can still be deadly. It can still cause encephalitis with associated brain damage.
Recently, we found a new issue with natural measles. The level of knowledge of the immune system has blossomed over the last 50 years since the measles vaccine was first introduced which allows us to study children with natural measles in a completely different way.
We are able to look at subsequent immunity to measles. We are also able to look at subsequent immunity in general.
We have known for years that you could not do a TB test soon after a measles infection, because if you did, it would be falsely negative. The measles virus would weaken the antibody system, therefore the antibodies that the TB test was looking for did not exist. The test was a negative test even in patients with TB.
We now know that this is more widespread than just with TB. Children who have natural measles infection develop an “immunologic amnesia.”
Researchers looked at three groups. One group was those who received the measles vaccine. The second group was those who did not receive the measles vaccine but also did not contract measles. The third group did not receive the measles vaccine and contracted natural measles.
Individuals in both the measles vaccine group and those who had neither the vaccine nor measles showed high levels of antibodies in general.
Children with natural measles showed a drop in overall antibodies after the infection. Those with mild infection showed a 33% drop. Those with severe infection showed a 40% drop.
The expectation was that the levels would ultimately return to normal over a period of months to years. However, in the meantime, children would remain more susceptible to other childhood infections.
In 1960, before the measles vaccine and well after antibiotics were common, 314 children per 100,000 live births died of pneumonia.
In 1999, after the measles vaccine that number dropped to 8 per 100,000. We will never know how many of those extra deaths were due to natural measles.
We now know that not getting a measles immunization increases your risk of death from other infections as well.
I am glad I was smart enough to give my kids the measles vaccine.