Pertussis Should Scare You: A Rebuttal

A friend of mine sent me a link to this Facebook video, featuring a mother who had lost one baby and decided not to vaccinate her second one. We both agreed that it was full of easily refuted assertions, but that it had gained enough traction over the months that it was nonetheless worth refuting.

I do want to start by saying that I feel for this mother. It’s logical (though ill-advised) to avoid vaccines if you believe they killed your child. I have no information about her first child’s medical issues and what lead to his death (nor should I), but she is convinced and I have ever reason to believe there would be no convincing her otherwise. So I will not attempt that.

Her argument, rife with holes, is that pertussis as a disease is so rare and deaths from it rarer still that it isn’t worth preventing. This argument is common and it gains traction because parents loved to be talked out of not worrying about something. So let’s break down what this mother claims and why it is wrong.

Claim 1: You are unlikely to die from pertussis

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This section argues that children do not need to be vaccinated against pertussis because so few people actually die from it. The screen grab above shows her math: 20 deaths from pertussis in the U.S. out of 40,000 cases each year. The claim is that you have a mere 0.05% chance of dying from pertussis if you catch it.

For your average adult, this is a perfectly reasonable way to assuage your fears of catching pertussis yourself. If you get pertussis as an adult, it highly unlikely that it will kill you. Don’t freak out, and go to the doctor to get antibiotics so that you don’t spread it to others.

For a baby under six months old, however, the odds of death from pertussis are much, much higher. Those 20 pertussis deaths a year are almost entirely in those young babies. In fact, a child under one year old has a 1% chance of dying from pertussis, and the odds of death are greater the younger a baby is. It’s important to note that the risk of pertussis is about more than death. A child under one year old who contracts pertussis has a 23% chance of developing pneumonia, which could mean hospitalization. Half of all babies under one who get pertussis end up in the hospital. Pertussis can also leave a young child with permanent disabilities or chronic illnesses. Suffice it to say that it is far better for your baby to avoid getting pertussis.

Claim 2: You probably aren’t even going to catch pertussis

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This claim hinges on dividing the number of pertussis cases per year in the U.S. by the total population of the U.S. She claims that you have a 0.012% chance of developing pertussis–full stop. There are a number of obvious and glaring errors with this claim and its ensuing math.

  1. A person can develop pertussis multiple times in their lifetime, which is most often longer than one year.
  2. She changes the question from, “What are your baby’s chances of dying from pertussis” to “Are you going to get pertussis” once again.
  3. Um, vaccines.

And really, point #3 is the crucial one here. Sure, 40,000 people develop pertussis today, in the age of vaccines. And sure, you live today. But if we are going to go about making videos talking about not vaccinating because pertussis isn’t a big deal, we need to look at what the odds of developing pertussis would be without vaccines.

The CDC tells us:

Before pertussis vaccines became widely available in the 1940s, about 200,000 children got sick with it each year in the United States and about 9,000 died as a result of the infection.

The difference without vaccines is significant, and notice the emphasis on children in the CDC’s statistics. The population of children in the United States right now is approximately 76,000,000. That’s a 0.26% chance of a child living in a time without vaccines developing pertussis, again–far greater than her 0.012% claim. And those 9,000 deaths alone disprove the claim that we can stop vaccinating because pertussis isn’t a big deal. Pertussis is less of a big deal than it was a few generations ago because of vaccines.

Claim 3: You will never die from pertussis

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I think you probably know where I am going with this. If you are reading this blog post, you have very little chance of dying from pertussis because you aren’t an infant and you know how to read. But if you do know how to read, you already know that she is using the wrong numbers.

Which numbers should she use? How about the pertussis death rate before vaccines (9,000) by today’s under 18 population (76,000,000). [Note: I recognize, even those numbers are not correct because the population today is larger and because we have better means of treating pertussis. But play along.]

The answer is not 0.00000629%. It’s 0.0118%. And it would be even higher if I were able to suss out the population of Americans under 6 months old and the deaths before vaccines that occurred in that age range.

Claim 4: The pertussis vaccine is super dangerous

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The crux of this claim is that the pertussis vaccine causes 48,600 deaths a year. (She lists other supposed ill effects of the vaccine, but since she didn’t tackle pertussis complications and hospitalizations, I’m going to forego the rest of her claims, as well.)

Where does she get these numbers? From VAERS, of course. VAERS is an open recording system for adverse events following vaccinations. Literally anyone can report something to VAERS. VAERS reports have included car accidents and turning into the Incredible Hulk. And according to her spelunking through VAERS, she found 486 claims of death (note: total and not per year) in the database.

She arrived at her vastly over-inflated number by claiming that only 1% of adverse events are made to VAERS. Which–okay. Why she assumes that means only 1% of deaths following vaccines are reported is sort of stunning. I have always assumed it meant that one year I had the super sore arm from my flu vaccine and didn’t report it. In any case, it is an amazing logical leap because if the pertussis vaccine were genuinely causing the deaths of 48,000 Americans, people would notice.

But what are the real risks of the pertussis vaccine? Moderate side effects listed by the CDC include fever over 102°F (about 1 in 100 adolescents or 1 in 250 adults) and swelling of the entire arm where the shot was given (up to about 1 in 500). The only known severe side effect the CDC lists is swelling, severe pain, bleeding, and redness in the arm where the shot was given (rare). And we all acknowledge the one-in-a-million chance of an allergic reaction to the vaccine.

You should vaccinate your baby.

In fact, mothers should vaccinate their babies before they are even born by receiving a pertussis (Tdap) vaccine during the third trimester of pregnancy because this is what pertussis actually is:




One thought on “Pertussis Should Scare You: A Rebuttal

  1. I would also note that a child’s risk of catching pertussis also depends on local vaccination rates and whether or not that child up-to-date on vaccinations. Looking at outbreaks in places like California and Oregon show that pertussis cases cluster in places where vaccination rates are lower, and children who are unvaccinated have an increased risk – something like 2-20 times the risk, depending upon their age.


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