Maternal Tdap and influenza vaccination uptake 2017-2021 in the United States: Implications for maternal RSV vaccine uptake in the future.

BACKGROUND: Assessment of maternal vaccine coverage is important for understanding and quantifying the impact of currently recommended vaccines as well as modeling the potential impact of future vaccines. However, existing data lack detail regarding uptake according to week of gestational age (wGA). Such granularity is valuable for more accurate estimation of vaccine impact. OBJECTIVE: To summarize contemporary maternal Tdap vaccination uptake, overall, yearly, and by wGA, and maternal influenza vaccination uptake, overall, by influenza observation year, immunization month, and delivery month, in the US. METHODS: Female patients 18-49 years of age with a pregnancy resulting in a live born infant (i.e., delivery) between 2017 and 2021 were selected from the Optum electronic health records (EHRs) database. Recently published gestational age algorithms were utilized to estimate wGA. RESULTS: Of 1,021,260 deliveries among 886,660 women between 2017-2021, 55.1% had Tdap vaccination during pregnancy; vaccine coverage varied slightly by year (2017: 56.6%; 2018: 55.2%; 2019: 55.2%; 2020: 54.7%; 2021: 52.1%). Most (64.4%) maternal Tdap vaccinations occurred 27-32 wGA; 79.5% occurred during the entire 10-week recommended vaccination window (27-36 wGA). In the evaluation of influenza vaccination uptake (n=798,113 deliveries; 714,841 women), 33.5% of deliveries had influenza vaccination during influenza observation years 2017-2021, most (73.0%) of which occurred during influenza peak activity months (October-January) with approximately one-quarter (27.0%) of vaccinations having occurred during the off-peak months, mostly in September. CONCLUSIONS: In this large contemporary analysis of EHR data, uptake of Tdap vaccination during pregnancy was consistent with previously published estimates; notably, most vaccination occurred early in the recommended 27-36 wGA window. Maternal influenza vaccination uptake largely correlated with peak influenza activity months and not gestational age. These study findings may have important implications for estimating the potential uptake and impact of future maternal vaccines.

Maternal Self-Report of Tetanus Diphtheria Pertussis Vaccination during Pregnancy Correlates with Patient-Specific Electronic Medical Records.

OBJECTIVES: To evaluate the concordance between maternal report of antepartum tetanus, diphtheria, pertussis (Tdap) vaccination and vaccination status documented in the electronic medical record (EMR), as well as factors associated with discordance. STUDY DESIGN: A survey was completed by a convenience sample of postpartum patients in a New York metropolitan hospital. The survey collected patients' demographic information, health beliefs, and whether they received Tdap vaccine during this pregnancy. The patient's Tdap vaccination status was abstracted from the EMR, a combination of data gathered from the obstetrician and patient's hospital record. Kappa statistics measured the agreement between maternal report and EMR on antepartum Tdap vaccination. Univariate and multivariable logistic regression analyses were performed to identify maternal characteristics associated with discordance. RESULTS: Of the 1571 patients with Tdap status available in the EMR, 1549 patients (92%) reported on receipt status for Tdap vaccination during pregnancy; 1328 maternal reports (86%) agreed with the EMR for Tdap status (kappa = 0.72, 95% CI 0.68-0.75). Several factors were statistically significant in multivariable analyses: lower income was associated with greater discordance (ie, overreporting; P = .02), as well as certain health beliefs including "Pregnant women should be concerned about the possibility of pertussis in their babies" (aOR 2.86, 95% CI 1.02-8.04) and "My friends would probably think getting a Tdap vaccine is a good idea" (aOR 2.36, 95% CI 1.11-4.99). CONCLUSIONS: Maternal recall of Tdap vaccination during pregnancy is consistent with the EMR. This supports the value of maternal report in determining Tdap vaccination status, which is especially important when vaccination records are not available.

Infant antibody levels following 10-valent pneumococcal-protein D conjugate and DTaP-Hib vaccinations in the first year of life after maternal Tdap vaccination: An open-label, parallel, randomised controlled trial.

BACKGROUND: Maternal antibody levels after Tdap vaccination during pregnancy may affect infant primary antibody responses to pertussis, Tetanus toxoid (TT), Diphtheria toxoid (DT) vaccinations and pneumococcal vaccines with diphtheria toxin mutants like CRM197 as carrier protein. METHODS: Mothers were recruited in an open label randomised parallel controlled trial in 2014-2016 through midwifes. They received Tdap [Boostrix] at 30-32 weeks of pregnancy (n = 58) or within 48 h after delivery (n = 60). Infants received DTaP-IPV-Hib-HepB [Infanrix Hexa] and 10-valent protein D conjugated pneumococcal conjugate vaccine (PHiD-CV10 [Synflorix]) at age 3, 5 and 11 months. We now report on infant specific IgG levels towards DT, TT, Haemophilus influenzae type b polyribosylribitol phosphate (Hib PRP) and PHiD-CV10 before and after primary- and booster vaccination as secondary study endpoints; pertussis antibodies were the primary endpoint of the study. This trial is registered in clinicaltrialsregister.eu (EudraCT 2012-004006-9) and trialregister.nl (NTR number NTR4314). FINDINGS: Post primary vaccinations, antibody levels to DT, but not TT, were significantly lower after Tdap vaccination during pregnancy compared to controls (GMC ratio 0.4, 95% CI 0.3-0.6 and 0.9, 95% CI 0.6-1.2, respectively). Antibodies to serotype 19F were significantly lower in the maternal Tdap group, whereas there were no differences in antibody levels to Hib PRP and the other 9 pneumococcal serotypes. Post booster vaccinations, no significant differences were observed, except for DT. INTERPRETATION: Maternal Tdap vaccination results in significant interference with infants responses not only to DT but also to conjugated pneumococcal vaccines containing DT mutants as carrier proteins. These interactions after maternal Tdap vaccination need to be taken into account when designing infants' national immunization schedules and choice of vaccines. FUNDING: The Dutch Ministry of Health, Welfare and Sport.