5 Things About the DTaP vaccine: Adding Insight and Correcting Misinterpretation

From www.michigan.gov Dept. of Community Health

New studies about DTaP vaccine are making headlines, and causing anti-vaccine opinionists to share interpretive nonsense. 

It is increasingly common knowledge that we are having an international problem with pertussis (whooping cough). Just check out the green circleson this map. Researchers are actively trying to determine why outbreaks are continuing to spread despite good vaccination rates. Most importantly, they are trying to find out why are babies are dying from pertussis today.

Two recent studies have offered clues. In one study, researchers found that vaccinated baboons were able to transmit pertussis-causing bacteria to unvaccinated cage-mates. The observation in these primates is challenging the concept of “cocooning” a newborn, increasing worry about the possibility of a vaccinated person spreading infection although they have little or no symptoms of pertussis. Other studies are continuing to demonstrate that the immunity provided by the DTaP vaccinedoes not last as long as previously thought, suggesting a change to the vaccine schedule, or the vaccine itself, would be beneficial to our families. 

Standing alone, these studies do appear alarming. They seem to suggest that our families are not adequately protected from pertussis, regardless of being vaccinated or not. It is important, however, to understand that these papers are a few grains of sand in the beach that is DTaP vaccine research. Although certainly interesting, they only suggest new directions for further experiments and recommendations. They do not represent an about-face to the evidence that supports the DTaP vaccine. 

Sadly, some anti-vaccine enthusiasts are taking these studies, picking out pieces that fit into their personal schema, and using these bits of knowledge to share damaging misinformation about the continuing need to vaccinate ourselves and our children against whooping cough. Some are even promoting and encouraging the dangerous practice of actively keeping everyone around a newborn unvaccinated, so that if an older child or adult becomes infected with pertussis they will become assuredly symptomatic and “intentionally isolate” themselves to avoid spreading the disease to the newborn. In addition, posts are encouraging pregnant women to avoid the TDaP vaccine “at all costs.” 

This misinterpretation of the science is dangerous. It’s risky and naive. And despite the writer’s visible disclaimer stating, “I am not a doctor. This is a personal opinion piece”; it is my opinion that the writer is both personally and socially irresponsible. 

Here is what we know:

1. It is true that the DTaP vaccine is not working as well we would like. However, IT IS still working. The vaccine is preventing illness in vaccinated older children. In addition, these studies confirm that the unvaccinated have a greater rate of getting disease. These studies do nothing to suggest that remaining unvaccinated will allow your family to be at a competitive advantage against whooping cough, nor do they suggest that contracting natural pertussis will decrease disease rates. 
2. Baboons are cool. Primate studies are a great way to study patterns of disease, and can provide amazing insight into our human world. The results of this research would be much more alarming if vaccinated primates were spreading disease to vaccinated primates. An important take-away is that the unvaccinated cage-mates were still ones susceptible to disease. 
3. Pertussis is stealthy. It starts like any common cold. By the time the characteristic “whoop” is heard, the infected individual has already coughed bacteria all over the place. Ensuring that an unvaccinated infant is not exposed to pertussis is practically implausible, especially with other caregivers and children in the home. In addition, it is important to know that acquiring natural pertussis does NOT provide life-long immunity. The best defense is for all people around an infant to get vaccinated as soon as possible, and on schedule. 
4. Pregnant women should be getting the TDaP vaccine during the 3rd trimester of every pregnancy. In addition to protecting the mother, this is an attempt to protect the unborn baby. After the shot, the mom’s level of protective antibody rises in her own bloodstream and is passed to her baby through the umbilical cord. It’s a way for mom to do the immune-system “heavy lifting”, while letting the infant reap the reward of the work. The antibodies shared from mom to baby last about 12 weeks after the baby is born, helping to protect the infant until the DTaP vaccine can be given to actively continue protection. 
5. Changes are likely coming. These studies are a brilliant example of how science is constantly refining itself and taking steps to make the health of our families better. As our leading vaccinologists gather more data, adjusted vaccine schedules - or even new vaccines - may be available in the future. 

Bottom line: The DTaP still matters. For infants and children, they should receive all doses of the vaccine, on schedule. Pregnant women should be getting vaccinated to protect their new babies. Expect changes to the vaccine schedule in the future. Until then, use valid sources of information to make vaccine choices for your family. 

Thanks to Dr. Jason Newland, pediatric infectious disease specialist, for his help with this piece. Follow him on Twitter @JasonGNewland for great infectious disease information.