The whooping cough vaccine your children get may not work as well as the one you got as a kid

About 20 years ago, the United States and a few other countries started using a different pertussis vaccine than had been used previously. The change was in response to public fear about some very rare neurological disorders that may or may not have had a relationship to that older vaccine (it couldn't ever be proven one way or the other).

The vaccine we use today was created to get around any possible mechanism for those disorders and, along the way, ended up having lower rates of the less-troubling (and far, far more common) sort of side effects, as well. Think short-term redness, swelling, or pain at the site of injection.

The downside, reports Maryn McKenna, is that this new vaccine might not be as effective as the old one. In fact, scientists at the Centers for Disease Control, Kaiser Permanente Medical Center in San Rafael, Calif., and Australia's University of Queensland’s Children’s Medical Research Unit, are raising the possibility that a less effective vaccine could be part of why we're now seeing a big increase in pertussis outbreaks.

In the most recent research, a letter published Tuesday night in JAMA, researchers in Queensland, Australia examined the incidence of whooping cough in children who were born in 1998, the year in which that province began phasing out whole-cell pertussis vaccine (known as there as DTwP) in favor of less-reactive acellular vaccine (known as DTaP). Children who were born in that year and received a complete series of infant pertussis shots (at 2, 4 and 6 months) might have received all-whole cell, all-acellular, or a mix — and because of the excellent record-keeping of the state-based healthcare system, researchers were able to confirm which children received which shots.

The researchers were prompted to investigate because, like the US, Australia is enduring a ferocious pertussis epidemic. When they examined the disease history for 40,694 children whose vaccine history could be verified, they found 267 pertussis cases between 1999 and 2011. They said:

"Children who received a 3-dose DTaP primary course had higher rates of pertussis than those who received a 3-dose DTwP primary course in the preepidemic and outbreak periods. Among those who received mixed courses, rates in the current epidemic were highest for children receiving DTaP as their first dose. This pattern remained when looking at subgroups with 1 or 2 DTwP doses in the first year of life, although it did not reach statistical significance. Children who received a mixed course with DTwP as the initial dose had incidence rates that were between rates for the pure course DTwP and DTaP cohorts."

You can read the rest of the story at Maryn's Superbug blog

A key thing to remember: This is a nuanced theory that may or may not turn out to be right. But, if it does turn out that this vaccine isn't as effective as we want it to be, that's not a dark mark against vaccines, in general. Sometimes, medicine doesn't work as well as intended. It's a risk of medicine. And the fact that it's major research institutions pointing this possibility out, should give people some comfort in the scientific process. If doctors and organizations who promote childhood vaccination are all in the pockets of an evil conspiracy then there would be no reason why they'd ever do research like this, or talk about it publicly.

Image: Day 59, Project 365 - 12.18.09, a Creative Commons Attribution (2.0) image from williambrawley's photostream


  1. We had an adult pertussis outbreak here a few years ago.  It seemed quite weird for a disease that nobody seemed to get when I was a child.

  2. Are vaccines harmful to you in any way?  A lot of people think that they cause autism, but those are the same people who think cell phones cause cancer.  Enlighten me, oh Boing Boing commentators.

      1. Short answer “Maybe”. As the parent of a child who had a (fortunately mild and treatable) reaction to DTaP I’ve dealt with real actual facts and a vast mountain of bullshit on the topic. 99% of the anti-vac crowd are whack-jobs, spreading FUD and blindly repeating long-disproven theories.

        Unfortunately the pro-vac side is full of “circle the wagon” denialism – they will deny things like the rate of polio caused by the use of the live-virus vaccine. They’ll deny that Rotashield ever happened. They’ll deny that off-label use happens. And they’ll particularly deny that anything bad ever happens to any child who gets vaccinated. The whole establishment is cloaked in “trust us, we’re the doctors, we know what’s best for you” attitude that sets my teeth on edge.

        If you want real info you have to dig. One of my treasured possessions is a paper reprint sent to me by a doctor in Japan who led a study of the effects of the varicella vaccine, which has been available optionally there since 1975. He was able to compare populations that chose to get the vaccine versus those that got the childhood disease and showed, among other things, that the initial US vaccination regime was leading to immunization failure in post-adolescent males (18-22). As a result of this and other work the regime was changed and now kids get the varicella vaccine later in life and don’t lose their immunity.

        TL;DR – vaccines are an important, life-saving tool. But like all of medicine modern and ancient they need to be understood as a tool, with both pros and cons. Sadly, nobody wants to hear such nuanced stories.

        1. Sadly, nobody wants to hear such nuanced stories.

          To the contrary, the bulk of the population and the media want to hear nuanced stories so that they can headline the one tiny little nuance and ignore the bulk of the story.

    1. Vaccines can carry with them a certain risk of adverse effects. In every case of vaccines which are routinely given to the public, these are much, much rarer and on the whole much less of a problem than the target of the vaccines.

      For example, the whole-cell pertussis vaccine, according to a 1997 CDC recommendation, had instances of hypotonic-hyporesponsive episodes and convulsions in around 1 of every 2,000 children. A Brazilian paper I’m looking at now reported 4,000 cases of those two effects in 18.7 million doses. I’m not aware of any of these cases resulting in any lasting adverse effects, however.

      In looking to compare to the acellular versions, I found one paper suggesting an 80% decrease in systemic adverse effects.

      To give another example, largely taken from Wikipedia, smallpox vaccines carry a risk of severe adverse reactions of somewhere between 14 to 500 out of every million people, and have a risk of causing death of around one in a million; around one in a thousand people vaccinated experienced serious but not life-threatening reactions.

      On the other hand, smallpox is highly contagious and can easily kill one in every three or four people, so until smallpox had been eradicated, the risks involved in taking the vaccine were very, very worthwhile.

    2., Orac at Respectful Insolence even the Bad Astronomer have full archive sections dedicated to vaccine safety.
      What a lot of people don’t get is the scrutiny level for vaccines means even random shit happens coincidences get report as part of vaccine regulation. So it looks in numbers like there are more side effects than there are. From what I have read over the years the only provable direct harm has been from contamination or misuse and that happens with all types of medicine even then in vaccines  it has happened less than all the other medical products out there. As for the Autism- full of shit based on fraud so someone could make money in lawsuits.

    3.  Might as well ask if flouride in the water can hurt you. Not as if the answer would matter, after all.

  3. Lol, as I write this, I am waiting for the results of my whooping cough test. It sucks beyonds all reason.

    1. Having had whooping cough a few years ago, that last sentence is an extremely accurate pun on the condition. You are walking along and, with no warning whatsoever, are hit by an uncontrollable and sharp intake of breath. It is most bizarre.

      1.  I had whooping cough as a child, before there was any vaccine. It was the sickest I can remember ever being as a child.

        Of course, having suffered through dengue fever and dysentary as an adult, I think I’d rather be coughing.

  4. I will appreciate the work that goes into running this down and the result it bears.

    However I know too many anti-vaccine people in my community to set aside my conviction that current pertussis outbreaks are likely a definitive result of that crowd breaking herd immunity.

    It’s hard to view this shit rationally with a newborn that’s got more than a few weeks of vulnerability left before shots begin, but Imma gonna, cause it don’t pay not too.

      1. THIS., 

        For the whooping cough to spread, it must make the leap from one vulnerable person to another. If the general population is sufficiently vaccinated, then most vulnerable persons are surrounded by the non-vulnerable, and thus protected. Once the vaccination rates go down, the bug begins to spread. 

        1. That’s right, and when among the parents you end up associating with you learn that there are more than a few who seem otherwise rational but are avowed anti-vaccine for themselves and their kids, it weirds you out. 

          Sure, my kids will be keeping their kids safer, but my newborn is in the riskiest group and is vulnerable to their kids if a chain of infection reaches one of those many. 

          It’s not particularly fair to my newborn. Since that whole autism scare has been long blown out of the water I find the remaining justifications mere doggedness, refusal to be wrong, a shame. Screw your shame on such matters.

          A few I know are apparently trying to “be natural”… which if they were honest about that seems to include accepting the risk of transmittable disease that their own parents shielded them from with vaccinations. I know of one parent set that seems to think that vaccines are some great conspiracy or autism-causing, but I couldn’t possibly confront them, because crazy people in person give me headaches.

          I can keep them from my home thankfully, and their kids too, and make sure I’m up to date myself to protect my lil-est one. 

          To be honest I don’t like it when I consider that I would prefer immunization/vaccines to be required for participation in public youth oriented systems like schools and such, but dammit, it’s not really my health on the line.

          Anti-vaccine isn’t just a fallacy, it’s rude.

          1. Anti-vax is particularly dangerous because it’s a form of woo that has the potential to HARM and KILL non-practitioners.

            It’s fine to talk about magnetic water, or superfoods, or chiropractry, or other flavor-of-the-month brands of woo until you’re blue in the face (and broke), that’s your right. You may even force your kids into it, (dumb through-and-through, though it is) that’s your right too, but an anti-vax families’ kids make already-vax’ed-kids, and especially, too-young-to-vax-kids, more vulnerable to PREVENTABLE illness, which isn’t just rude, it’s being borderline sociopathic

            …and for what?

  5. The change to acellular pertussis vaccines was not merely due to unfounded fear about the possibility of rare cases of lasting brain damage. While there was disagreement about the potential for lasting brain damage, it is my understanding that the acellular vaccines cause significantly less frequent adverse side effects in general.

  6. Since Western Australia had an outbreak earlier in the year (We had just had a baby so all the adults needed to get immunised again, otherwise it would have probably passed me by unnoticed)
    This is fairly worrying. The outbreak was first noticed inn Denmark, a town with a high antvaxer popuilation, and spread across the southwest.
    However there was some suggestion that vaccinated people can be carriers, is this true?

    1. I was told that a booster is required now, where it wasn’t needed before. This, kid you not, is the second damn time I’ve had whooping cough (if this test comes back positive- they wouldn’t test last time. This time I insisted, as my sister has a newborn), despite being immunized as a child back in the 70’s. I was exposed at work, and due to a propensity for stupid respiratory problems, I hit the jackpot and appear to have it again. I can’t go ANYWHERE until either the test comes back negative, or until I’ve finished 5 days of the antibiotics. I’m in semi-quarantine, and we’re hoping that since my cough didn’t start until a few days after I had last seen and held my three-week old nephew, he’ll be safe.

  7. Maggie, I wish you had *led* your post with the disclaimer you have at the end, to anchor the readers to be cautious, thoughtful readers before exposing the details behind the headline….guide us how to shape what we read before we fly off the handle. Because heaven knows so many folks fly off the handle when the news is about vaccines. 

    I’m not sayin’ folks in this comment string are flying off the handle (maybe some folks are, tl;dr string): I’m thinking of the conspiracy-lovin’, vaccine-hatin’, big-pharma-suspectin’, possibly-non-commentin’ readership population segment generally.

  8. If you can still get the disease, then it isn’t a vaccine.  Break out the lawyers… this shit is false advertising.

  9. To address the point of the blog post, one of the unstated problems with vaccinations in the US is that they’re rolled out with (in my opinion) vastly inadequate testing.  They’re rushed to market with no longitudinal studies and so we’re SHOCKED, SHOCKED when effects we didn’t study show up 10 or 20 years after the vaccine is administered.  See my comment above re the varicella vaccine, which I had to go to Japan to find a 25-year study on.  Likewise, the only study I could find on HiB that was 10 years or more took place in Finland.

    So I would venture to guess that the acellular vaccine was not studied for its 10-12 year efficacy. Instead, we turned our children into test subjects since it is they (and we) who will prove or disprove the long-term efficacy of this and almost every other vaccine.

    No, I’m not the least bit cranky about this :(

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