Pertussis Vaccine DTaP Not Giving Lasting Immunity
Whooping cough (pertussis) is perhaps one of the most scary infections newborns can get, right up there with meningitis, and for those of us in the medical field, we have images of infants on respirators in the neonatal or pediatric intensive care units. Having said that, we need to put things in perspective as to how common this infection is. In the past 10 years in the USA, we have averaged 18-20 deaths a year with all being in the 3 months and under age group. This is out of about 4 million births a year, and devastating to the families of course.
The article, “Tdap Vaccine Effectiveness in Adolescents During the 2012 Washington State Pertussis Epidemic,” just published in Pediatrics, points out a few important facts:
- We switched from whole cell pertussis vaccine (DPT) to the acellular DTaP in 1997
- We added a dose of Tdap to teenagers in 2005
- For those who got the Tdap, it’s effectiveness was 73% at a year and 34% at 2-4 years. You can read more on that here…
In 2012, the US had their worst year for pertussis cases in recent memory. Washington State had almost 5000 cases, and in my practice alone I had 20 cases (more than I had seen in my entire career). It is now clear, as this article points out, that the acellular vaccine is not as effective as we would like it to be. The old whole cell vaccine was horrible in terms of side effects, causing very high fevers, seizures, and deaths.
Why are there far fewer cases of pertussis in 2013 and 2014? Was it some new vaccine? No. There are seasonal variations in diseases and this is a point that is often missed when we are talking about vaccines. Too often a vaccine is given all the credit for the reduction in disease or we blame a vaccine as a failure when there is a huge increase.
The pertussis vaccines have a large amount of aluminum and thus my strong recommendation against giving this vaccine in pregnancy. We simply do not have any safety studies that would make that recommendation reasonable. Because pertussis can be deadly, especially to infants, I do recommend this vaccine on the regular CDC schedule and even though this article points out that the protection provided is not lasting, it may be enough to provide a significant measure of herd immunity and thus protect the youngest infants who are at greatest risk of death.
If you are bringing a newborn home, the best thing to do is make sure all family members and care givers have had a recent pertussis vaccine. As they develop a new vaccine, I hope they will find a safer adjuvant so we can remove the aluminum and thus safely vaccinate pregnant moms as well. For now, if you might be getting pregnant in the next year or two, I recommend women of child bearing age get the Tdap (before you get pregnant). Unless your family has a family history of autism, autoimmune issues, or troubles with toxins, etc. I do recommend the Tdap for infants as pertussis risk is real and we will likely have another year like 2012.