Sunday, September 9, 2018

What do the Numbers Mean? A Story of Measles and Measles Vaccine

As I have mentioned previously, I'm getting email blasts every day from various medical news outlets I am connected to (some on purpose, some just come to me unbidden!), and this thing about "deaths from measles vaccines exceed deaths from measles in the U.S" plopped into my inbox at the end of August.

So I read it. Seemed like an "antivaxer" point of view so I fact checked it at a site called Ballotpedia, a source for fact-checking claims made by politicians and people running for office. The data are real, but the author points out that while there were 12 reported deaths between 2000 and 2016 from measles in the U.S., only 2 were verified as caused by the disease. In the same period, 104 deaths were reportedly caused after receiving the vaccine. However, they note, verification is sketchy because the Vaccine Adverse Event Reporting System (VAERS) takes reports from anyone, including lay-persons, and verification depends in large part on the contents of the individual reports.

This basically means we have numbers but no context. I'll try to provide some.

Measles is a leading cause of death among children worldwide. What this doesn't tell you is that measles deaths are connected to the level of development. Less development (clean water, good food, access to health care) is connected to a higher death rate. In simple terms it can be said that if you are poor, hungry, and exposed to lots of germs in your water source, or around untreated human waste, or exposed to high levels of pollution, and you are without access to doctors and nurses, you have a higher chance of dying from this infectious disease.

VAERS reporting just says that one thing happened (a vaccine) and then another thing happened (in this example, a death). By digging into each report, it is possible to sort out likelier cases of vaccine-caused-death and less likely ones, perhaps events that were linked in time to some extent, but there were other factors to consider as the real cause of the death.

In this, Ballotpedia is right, and so are doctors and public health experts. The Centers for Disease Control discusses this weakness right on the VAERS website. However, the difference between 2-12 deaths from measles and 104 deaths from the vaccine--no matter what the flaws in the VAERS reporting--is a big difference!

To antivaxers, these data would suggest that the "cure is worse than the disease", although that would be leaving out the millions of kids who were vaccinated without dying afterwards.

To vaccine advocates, this suggests that the vaccine-caused-death data are flawed, and even so, the disease is worse than the cure. Clinicians share horror stories of "unnecessary" measles deaths to drive the point home.

To me, both sides are wrong.

It is easy to blame a childhood death from a disease like measles on unruly parents who refuse to see the light of science, when it's possible that in any given case, there may have been other factors at work. Most measles deaths are caused by encephalitis, an inflammation of the brain, a condition difficult to treat with today's approaches (mainly steroids or immune globulins). It still works 95% of the time in kids and 75% of the time adults. Homeopathy has a number of remedies that may be helpful--although they don't get used much because most doctors don't "waste time" on such approaches. Belladonna (first stages), Stramonium, and Gelsemium are three remedies that have been used to good effect.

Measles encephalitis (ME) isn't the only potential cause of death, and ME itself can occur because of the direct effects of the virus or from the indirect effects of the immune system going crazy from the virus. Death can also ensue from pneumonia, shock, or other causes made worse by the measles infection. An early study found nearly 1/5th of deaths from measles were seen in persons with an underlying medical condition. Makes sense: if you're already sick, measles might make you sicker.

It is easy to blame a sequel, like death, on a vaccine if one thing (the vaccine) happened, and then another thing (death) happened, regardless of what mysterious process was actually going on underneath it all. The survivors of a death need a point of blame for the loss.

As many of you know, I'm not against vaccines. I'm not pro-vaccine either. For a lot of nurses and doctors, the broad strokes of the science and the potential for believing that one's work (i.e., immunizing large numbers of children) makes the world a safer, better place is enough to quiet any misgivings that arise from what are actually pretty isolated events. It is easy to see why doctors and nurses argue so urgently for scheduled vaccinations.

Parents, on the other hand, see only one kid--their own, and this focus can't accept the broad brush, the science of millions of other kids' experience with vaccines (other kids who are not their own). They want to untangle the matter, and if they cannot do so, it seems safer to avoid injecting their child with a product to prevent a disease they may never see. It is easy to see why some parents resist the pressure to vaccinate.

The email blast that started this blog entry is evidence that we aren't moving past this stage of the debate. It's still the same old thing. One side says the science is sound and that the aggregate good to the population outweighs the occasional catastrophe. The other side says, "Nope, not if that catastrophe might be my kid."

Interestingly, in a commercial for Bexsero, the moms argue that not vaccinating against meningitis-B "isn't a risk I'm willing to take." I commented on this in detail elsewhere in this blog. You know, when it comes to your kid, one's point of view could go either way. So whether one chooses the immunization route or not seems largely to depend on what risks, what threats, seem most immediate and dangerous.

This is the problem with this debate over vaccines.

I have yet to hear any public health advocates, politicians, parents, doctors, or nurses openly argue that individualizing approaches to immunization is a viable medical option. I have yet to hear any of these people argue that improving wealth equity, environmental science, and access to health care for all would also improve outcomes in measles--or any other of the many diseases we vaccinate against.

I suppose it is easier to carry on this fruitless argument than it is to come together to improve the foundational aspects of health that are so inequitably distributed in our world.

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