Real Questions and Answers to Anti-Vaxxers
So, this weekend, I got into it with a couple of anti-vaxxers about the ongoing measles outbreak. With that in mind, here are a few answers to the questions I was asked:
Doesn't VAERS demonstrate that vaccines are unsafe?
VAERS doesn't track vaccine-related deaths and injuries. It tracks all deaths and injuries due to anaphylaxis (or a variety of other causes) within the reporting period. For the MMR vaccine in particular, this includes all deaths associated with febrile seizures within a couple months of the vaccine.
In other words, it's a source of raw data about deaths that occur closely enough to vaccine administration that they might be related, not a source of confirmed (or even suspected!) vaccine-related deaths. It's the best starting point, though.
Over the past fifteen years, haven't more people died of the MMR vaccine than of measles?
Possibly. It doesn't matter. The MMR vaccine uses an attenuated virus, which means that it's still infectious in humans, and (accordingly) is somewhat more dangerous. Thrombocytic purpurea, febrile seizures, and anaphylaxis are all possible vaccine side effects, and VAERS requires that all instances of those side effects be reported to the CDC. On further review, there were no definitive deaths due to MMR vaccination for the reporting period between 1981 and 1995, but the present data does not rule out the mMR vaccine as a cause.
According to VAERS, there are up to 15 MMR-associated deaths per year. As long as endemic measles is eliminated in the United States, there will be more deaths from measles vaccines than there will be from measles. That's not even a matter of science. That's a matter of simple mathematics. But if herd immunity slips, measles will pop right back, and start killing the immunosuppressed people we can't vaccinate.
Measles isn't Ebola. Why do we care so much?
No, measles isn't Ebola. That's the problem.
The dangerousness of a disease is a function of its transmissibility times its lethality, not a function of its lethality alone. Which means that although measles isn't particularly fatal, it's also far, far more dangerous than Ebola.
0.2% of tens of millions of yearly cases is a much, much, much larger number than 75% of a few dozen yearly cases. In 2013, there were 145,000 measles deaths worldwide. In 2014, during the worst Ebola outbreak in history, the number of deaths was less than 10% that number.
Isn't the idea of herd immunity widely debunked?
By "widely debunked," you mean "a crank said it once in an op-ed," not "there are actual peer-reviewed studies on the matter," right? Herd immunity is precisely how we eliminated smallpox and how we have almost eliminated polio. The concept isn't just non-debunked. There are actual examples of using precisely that mechanism to wipe out huge, deadly, endemic diseases.
Measles is both (a) highly contagious, and (b) non-zoonotic, so it was initially thought that we could eliminate it relatively easily. But it turns out that it's so contagious that the complete-herd-immunity threshold is in fact very high. And we in fact reached that high threshold in the United States, and wiped it out.
Doesn't the decline in measles deaths which began in the 1890s -- long before the development of the measles vaccine -- demonstrate that the measles vaccine is ineffective?
I'd like to direct you to page 6 of the linked study (or page 270 of the PDF, if you prefer), because I imagine what you're obliquely citing is a dishonest anti-vaxxer infographic.
Deaths due to measles decreased substantially in the early part of the 20th century. That's the result of better nutrition and supportive care, not sanitation: measles is airborne, so sanitation has a minimal effect. The rate of infection remained stable until mass MMR vaccination began. Herd immunity was finally achieved when we realized that MMR vaccination needs a second booster shot for immunity to actually continue into adulthood.
What's the takeaway here?
The science on vaccine efficacy and safety is more settled than the science on anthropogenic global warming. It's more settled than the science on evolution. It's about as settled as heliocentric model of the solar system. We have wiped whole organisms off the face of the earth this way, all while keeping a population-wide morbidity and mortality tracking system.
For god's sake, if you have kids, get them vaccinated. In a wost-case scenario, you're talking about a risk of death that's less than a week's worth of driving. Even if the tradeoff isn't worth it for you -- and it is -- it isn't worth the other people you're putting at risk.