Influenza Vaccination Coverage, Pregnant Persons, United States

  • These monthly flu vaccination coverage estimates for pregnant persons are based on electronic health record (EHR) data from the Vaccine Safety Datalink (VSD), a collaboration between CDC’s Immunization Safety Office and nine integrated health care organizations.§ COVID-19 vaccination coverage for pregnant persons is available.
  • For any month’s coverage estimate, the denominator is the number of persons with a pregnancy during the current flu season (defined as August through March) beginning before or during the specified month. The numerator is the subset of the denominator who have received flu vaccination prior to or during pregnancy. The denominator increases as more persons are identified as pregnant or having been pregnant during the flu season. Cumulative vaccination coverage for one month may be lower than cumulative coverage for a previous month due to addition to the denominator of persons who are less likely to have received vaccination.^
  • Estimates for prior seasons for a given time period are based on the end-of-season estimates; the end-of-season estimates for a given time period may be higher than those generated earlier in the season.
  • Figure 3A. Monthly Cumulative Influenza Vaccination Coverage*, by Flu Season and Race/Ethnicity, Pregnant Persons 18-49 years, United States, Data Source: Vaccine Safety Datalink, Data are current through March 9, 2024.
  • Figure 3B. Cumulative Influenza Vaccination Coverage*, by Month, Flu Season, and Race/Ethnicity, Pregnant Persons 18-49 years, United States, Data Source: Vaccine Safety Datalink, Data are current through March 9, 2024.

*The coverage estimate for any given month may change as the season progresses.

^The following updates were implemented as of October 20, 2023, which resulted in decreased estimates for prior seasons:

  • Estimates for all seasons were adjusted to remove flu vaccinations received after pregnancy.
  • Vaccinations for people vaccinated before their pregnancy began were inadvertently included in the numerator of the coverage calculations in the months before their pregnancies were included in the denominator. Estimates were adjusted to correct this error.

These updates resulted in decreased coverage among all pregnant persons as of the end of March ranging from 7.7 to 9.2 percentage points for the four prior seasons.

§Naleway AL, Crane B, Irving SA, Bachman D, Vesco KK, Daley MF, Getahun D, Glenn SC, Hambidge SJ, Jackson LA, Klein NP, McCarthy NL, McClure DL, Panagiotakopoulos L, Panozzo CA, Vazquez-Benitez G, Weintraub ES, Zerbo O, Kharbanda EO. Vaccine Safety Datalink infrastructure enhancements for evaluating the safety of maternal vaccination. Ther Adv Drug Saf. 2021 Jun 14;12:20420986211021233. doi: 10.1177/20420986211021233. PMID: 34178302; PMCID: PMC8207278.