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Home » Why we vaccinate–to protect our children from pertussis

Why we vaccinate–to protect our children from pertussis

Last updated on October 1st, 2020 at 12:43 pm



During this past week, a 25 day old baby in Santa Barbara, CA died from pertussis, commonly known as whooping cough (caused by the Bordetella pertussis bacteria). The disease can be easily prevented by the DTaP or Tdap vaccines (also protect against tetanus and diphtheria), which can be given to infants as early as 6 weeks to 2 months old.

According to the California Department of Public Health, infants who are too young to be fully immunized or those who are not vaccinated are most vulnerable to severe and fatal cases of pertussis. In 2014, 66 of the pertussis hospitalizations cases were children four months of age or younger. Two infants have died of pertussis in California during 2014.

So this child died not because her parents were antivaccine (there’s no evidence one way or another), but because she was too young to be vaccinated, according to CDC recommendations. Because pertussis doesn’t magically appear out of thin air, it is transmitted by air usually from coughing or sneezing by someone who is infected, someone else could have given the disease to the baby. It could have been a close family member or friend. It could have been an infected child in a pediatricians office. It could have been someone coughing pertussis bacterium into the air in a grocery store.


This child’s parents probably did everything they could to protect their newborn infant, but pertussis is invisible, so unless you put a sterile bubble around the child, there’s nothing they really could have done. But that’s not completely true.

The CDC recommends a strategy called “cocooning,” which is a theory that if everyone who is in contact with a newborn is vaccinated, that should dramatically decrease the risk of pertussis being transmitted to the child. The evidence supporting the effectiveness of cocooning is moderate at best, but if everyone around the child is fully vaccinated against whooping cough (and frankly, all other vaccine preventable diseases), the risk of transmission is small.


There is actually better evidence that pregnant mothers who are vaccinated with Tdap during pregnancy pass on the immunity to the developing fetus, which means that the newborn has a good level of protection against the disease until it reaches the age that it can be properly vaccinated. And the safety of the vaccine, for pregnant mothers, is supported by evidence in a study of over 26,000 pregnant women who received the Tdap vaccine compared to 97,000 who did not. The researchers found that “Tdap during pregnancy was not associated with increased risk of hypertensive disorders of pregnancy or preterm or SGA birth.”

Now, to be fair, the researchers found a slight (0.6% percentage increase) risk of chorioamnionitis, an inflammation of the fetal membranes (amnion and chorion) due to a bacterial infection. This risk, however, was potentially due to unrelated factors not accounted for in the overall analysis, such as receipt of an epidural since nearly all the women with this infection received an epidural. In other words, it’s almost impossible to state whether the Tdap vaccine is causal to chorioamnionitis.

Some people might argue that with the waning immunity associated with the pertussis vaccine, it might not be useful. However, booster vaccinations for adults, teens and children who are in contact with the baby would increase the effectiveness of the vaccine. And, the scientific theory of the herd effect states that it is difficult for pertussis to pass from person to person to unvaccinated baby if a large percentage of individuals in a population are vaccinated against the disease. Then lower effectiveness of the vaccine becomes almost irrelevant.

I mourn for the baby. I mourn for the parents of this baby. We need to prevent these tragedies as a community by increasing the rate of vaccination against pertussis. It’s safe. It’s effective. And it’s the right thing to do.

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Michael Simpson

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