Are Vaccines the Real Microcephaly Culprit?

No. They are not. Vaccines are not causing microcephaly in Brazil.

If you have no idea what I am talking about, count yourself lucky and thank your friends for not bringing crazy to your social media feed. But since you are probably curious, here is a sample:

Dr. Tenpenny, the Ohio anti-vaccine activists behind sites like All About Breast Health and TruthKings has joined the conspiracy bandwagon in insisting that the Tdap vaccine given in pregnancy to prevent pertussis in mothers and their newborn babies, is the real cause of microcephaly, and not the Zika virus.

Their overly simplistic thought process is not new. These are the people who brought us “vaccines cause autism” and “the HPV vaccine causes ovarian failure,” which require the same “We did X and Y happened” thinking. Post hoc ergo propter hoc.

Except that the connection between Zika virus and microcephaly is established, unlike the uncertain causes of autism. Yet, organizations like the poorly-named National Vaccine Information Center and Natural News continue to promote this obviously wrong and crazy theory.

And like autism, there isn’t even a correlation. If there were a correlation between the Tdap vaccine given in pregnancy and microcephaly, we would see an epidemic of microcephaly in the United States, where the recommendation for this maternal vaccine has been in place since 2013 (one year before the Brazilian recommendation), and in Australia where a similar recommendation is in place. In other words, there isn’t a propter hoc to connect the post hoc to. There are simply conspiracy theorists throwing their darts at the vaccine target to see what sticks.

Let’s hope this dart doesn’t stick. While I would love to believe that pregnant women will shake their heads in disbelief over how outrageous these claims are, I know how vulnerable a woman can be to bad information while she is expecting a baby. And so we remind people that pertussis in an infant is terrifying, and the Tdap in pregnancy is safe.

And then file this post under “Things I can’t even believe I have to write.”