The following is for informational purposes only and not intended to be personal medical advice.

We get many questions from our patients as to our opinion on vaccination during pregnancy for pertussis (whooping cough). This is the Tdap vaccine which includes pertussis, tetanus and diptheria.

Our current recommendation is to avoid the Tdap during pregnancy.

Here’s why:

First. The CDC states that: “The whooping cough vaccine is very safe for you and your baby”[1].

However, as we have seen repeatedly, the CDC is currently not a reliable source of unbiased information[7][8]. Despite their recommendations and contention that it is “very safe” there have been no safety studies on pregnant women. Currently, there are two options for vaccination during pregnancy with the Tdap:

(1) Boostrix (Tdap – Category B – no human studies, animal studies seemed ok) Section 8.1, Line 319 of vaccine insert:

“There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, BOOSTRIX should be given to a pregnant woman only if clearly needed” [2].

(2) Adacel (Tdap -Category C – possibly adverse effects in animals and no human studies) Section 8.1 of vaccine insert, line 253:

“ It is also not known whether Adacel vaccine can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Adacel vaccine should be given to a pregnant woman only if clearly needed” [3].

Clearly the vaccine manufacturers are not confident that their vaccines are safe for pregnant women.

Second. It is not even clear that taking the risk and vaccinating during pregnancy will result in any protection at all to the child. In a study that looked at antibody levels in infants from mothers who were vaccinated with the Tdap during pregnancy, they found levels of 68.8 EU/mL [4]. However, a study that examined the level of antibodies that was protective against pertussis found that the average antibody level of children who developed severe pertussis was 79 (i.e., levels below 79 were not protective at all). The levels that were protective were 246! At levels of 156, children developed mild pertussis only [5]. In other words, a level of 68.8 offers little to no protection.

Third. A baboon study showed that when the mother was vaccinated with DTaP (not Tdap) the babies were protected from a challenge with pertussis. It is important to understand two things: (1) DTaP is not allowed to be administered to pregnant humans per the FDA due to safety concerns. Therefore, this study is not relevant and actually was cheating (using something much stronger than what is allowed to be used). (2) It is also worthwhile to note that while the DTaP protected children from symptoms of pertussis, it did not prevent infection with the organism. One study looked at the consequences of getting infected with b. pertussis without developing symptoms (i.e., what happens when you vaccinate for b. pertussis and encounter it). In that study they showed that such people had a significant increased risk of developing neurological disease [6].

In summary, there are no human safety studies done to determine whether the Tdap is safe during pregnancy. In the only studies we have found measuring anitbodies, the maternal transfer of antibodies doesn’t seem adequate to protect the baby anyway. The baboon study showing protection did not use the same vaccine and is therefore, irrelevant. In short, there doesn’t seem to be a clear benefit from having the Tdap and there may be unknown, long-term risks due to lack of controlled safety studies. If you do decide to get the Tdap, please make sure they order you Boostrix.

[2] BOOSTRIX Vaccine Insert download from FDA website
[3] ADACEL Vaccine Insert download from FDA website
[4] JAMA. 2014;311(17):1760-1769. doi:10.1001/jama.2014.3633.
[7] A group calling itself CDC Scientists Preserving Integrity, Diligence and Ethics in Research, or (CDC SPIDER), put a list of complaints in writing in a letter to CDC Chief of Staff and provided a copy of the letter to the public watchdog organization U.S. Right to Know (USRTK). The members of the group have elected to file the complaint anonymously for fear of retribution.
“It appears that our mission is being influenced and shaped by outside parties and rogue interests… and Congressional intent for our agency is being circumvented by some of our leaders. What concerns us most, is that it is becoming the norm and not the rare exception,”
[8] Senior CDC scientist and Whistleblower William Thompson recently stated through his attorneys: “I regret that my coauthors and I omitted statistically significant information in our 2004 article published in the journal Pediatrics. The omitted data suggested that African American males who received the MMR vaccine before age 36 months were at increased  risk for autism. Decisions were made regarding which findings to report after the data were collected, and I believe that the final study protocol was not followed. This very disturbing revelation was the subject of the movie Vaxxed.


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