Pregnant Women in California Need Better Tdap Vaccination Management

Just 30 percent of pregnant women whose infants developed pertussis were immunized with tetanus, diphtheria, and pertussis (Tdap) vaccine, according to a study published by the Centers for Disease Control and Prevention (CDC).

Most severe and fatal cases of pertussis occur in infants who have not yet started the primary pertussis vaccination series.

To reduce the incidence of pertussis in infants, the CDC recommends that pregnant women receive Tdap vaccine at the earliest opportunity, during 27–36 weeks’ gestation of each pregnancy. 

In this review of 66 California mothers of infants who became ill with pertussis in 2016, 20 mothers (30%) received Tdap vaccine during the time frame recommended by the CDC, all of whom were vaccinated in their prenatal clinic during a routine visit.

This new study identified 2 reasons for these under-vaccinations.

The first reason was substandard vaccine inventory management. Women whose healthcare providers stocked the Tdap vaccine on-site were 3 times more likely to have been vaccinated.

And, the second reason was related to insurance coverage. Expecting mothers with Medicaid were 40% less likely to receive a Tdap vaccination, or to receive it during gestation, regardless of the provider's inventory management practices. 

One additional vaccination, barrier was identified. 

Approximately 40 percent of the unvaccinated mothers in this CDC analysis never received a referral for Tdap vaccine to another vaccine provider, such as a pharmacy.

In California, pharmacists are permitted to provide immunizations, and all routinely recommended adult vaccines are covered by Medicaid when given in a provider’s office or in a pharmacy.

Recent state regulations require pharmacists to notify providers of immunizations administered and to enter all doses into the California Immunization Registry, making it possible for providers to know whether vaccine referrals to pharmacies are successful. 

However, stocking vaccines on-site in prenatal clinics is the best way to ensure that all pregnant women are vaccinated and reduce the incidence of pertussis among infants too young to be vaccinated, say these researchers. 

"Promoting on-site prenatal vaccination, educating providers about Tdap recommendations, and strengthening off-site referrals will likely improve Tdap vaccination coverage during pregnancy," the study authors note. 

This new California study is important since a pertussis outbreak in northern California is continuing to impact children. 

“Most of the recent pertussis cases have occurred in school-aged children, with infants at the greatest risk for severe complications,” said Dr. Matt Willis, Marin County’s Public Health Officer, in a press release, on June 4th, 2018. 

‘Unvaccinated children are at least 8 times more likely than fully vaccinated children to get pertussis and then spread it,” said Dr. Willis.

In related Tdap vaccine news:

On August 14th, 2018, children were not at an increased risk of autism after their mothers received tetanus, diphtheria, acellular pertussis (Tdap) vaccine during pregnancy, a new study found. 

On July 20th, 2018, a new report from the American College of Obstetricians and Gynecologists immunization committee’s opinion said there is no evidence of adverse fetal effects from vaccinating pregnant women with the Tdap vaccine.   

The authors of this study did not disclose any relevant conflicts of interest.