With all of the press recently about the measles outbreak at Disneyland, I wanted to take a look at the data around childhood vaccinations - and share what I'd learned. Turned out it wasn't quite as clear as I expected.
Before I dive in, let me state a few things. I am not a doctor or a nurse or a member of the medical community. I am not trained in vaccine development, delivery, or education. I do not have a vested financial interest in any of these vaccines. I'm not even a parent. But I do believe in vaccinations.
Over the last few months, King County Public Health has routinely published vaccination completion rates for area schools, and some reporting has focused on schools where the herd immunity levels are so low that it's remarkable the current measles outbreak hasn't reached our city in large numbers.
The national discussion on measles has reached fever-pitch, and in a way that's good - because measles has a frighteningly high transmission rate, and this epidemic is growing every day. It's not like last year's Ebola scare out of Dallas, which had a media response way out of proportion to what it should have been. According to Philip Eckhoff, PhD., whom I saw speak last month at a World Affairs Council talk on Ebola in 2015, a person with Ebola is likely to infect one, maybe two people. A person with measles is likely to infect 12 others who are unvaccinated. But perhaps it was the sensational nature of Ebola - the Hot Zone references and the exotic subtropical origin story that really scared people. Measles seems so mundane in comparison.
And Measles came up a lot at that talk about Ebola, because the clinicians and researchers were really worried about it. Think about it. They had been fighting Ebola for 8 months, and during that time, primary preventive medicine was effectively nonexistent. Hundreds of children should have received their Measles vaccinations, but they didn't. A Measles outbreak post-Ebola would be devastating to already decimated families and countries.
That caught me off-guard. Ebola researchers - people who had seen the effects of Ebola - were afraid of Measles. And they were puzzled about how we wouldn't want to vaccinate our children too.
The CDC has done an excellent job documenting diseases covered by routine childhood vaccinations, vaccination types, and Q&A for both parents and kids alike. Here's a list of the most common required childhood vaccinations, with links to the information pages on the CDC's site:
- Rubella (also known as German Measles)
- Hepatitis B
- Varicella (also known as Chicken Pox)
What you won't find on the site is a comparative herd immunity model - for all of these diseases together in reality. Here's the challenge. Let's say you research online and find the generally accepted herd immunity levels for each of these diseases (they're not on the CDC site, by and large - you need to read scientific publications for that). And then you want to put it into some sort of statistical simulation like the Guardian has so expertly done with a Measles model. All of these, save Hepatitis, are roughly transmitted in the same fashion - mucosal discharge (coughing, sneezing, talking, touching). Then you combine those disease behaviours with the population profile - vaccination levels for each of the diseases, any notes for those with compromised immune systems, and exposure and proximity. What results isn't a model, it's a mess. Or rather, it's a complex reality that most of us aren't really qualified to speak as experts on, no matter how much you read on the Interwebs. :)
Vaccinate. Or at least read Roald Dahl's touching letter about the death of his daughter to Measles.