Principal Findings and Interpretation
Slightly more than three-fifths of women with a live birth in 2019 reported influenza vaccination in the year before delivery, with a majority receiving it during pregnancy. In addition, approximately 73.7% of women received a Tdap vaccination during pregnancy. Prevalence estimates of influenza vaccination from PRAMS and the Internet panel survey conducted by the CDC for pregnant women for the 2019-2020 influenza season (61.2%)14 were similar, although not directly comparable due to different methodologies and time period assessed. The prevalence of Tdap vaccination from this Internet panel survey was 56.6%; the difference with our findings might be explained by the limited number of jurisdictions that included the PRAMS question on Tdap vaccination during pregnancy in 2019, the time period assessed, and inability of PRAMS survey to calculate the prevalence of Tdap vaccination by provider recommendation. The prevalence of influenza and Tdap vaccination varied across jurisdictions which might be explained by differences in provider and healthcare delivery practices, preferences and attitudes toward vaccination of women, and strategies implemented by jurisdictions to address barriers to maternal vaccination.
Examples of strategies several jurisdictions have implemented to address barriers to maternal vaccination include providing incentives to health plans, increasing access to vaccinations through alternative sites like pharmacies, and using data to identify populations and regions with substandard influenza vaccination rates.15 For example, compared with other jurisdictions, we found Massachusetts and Rhode Island were among the sites with the highest reported prevalence of influenza vaccination being offered or recommended by a healthcare provider and past-year influenza vaccination prevalence among women with a recent live birth. The Massachusetts Department of Health has a history of supporting vaccine education and access to vaccinations statewide through collaboration with community-based organizations to share tailored, accurate, and culturally appropriate messages about the importance of influenza vaccination as well as establishing additional venues, including obstetrics sites, to administer the vaccine.16 Massachusetts also has programs to reimburse public providers for administration of the vaccine to incentivize providers to incorporate vaccine programs in their practices. During the H1N1 pandemic, the Rhode Island Department of Health ensured that the influenza vaccine was accessible to pregnant women statewide by recruiting obstetric providers; this led to dramatic increases in influenza vaccination among pregnant women.17 Rhode Island’s Immunize for Life initiative offers pregnant women home visitation that includes vaccine education and referral.18
Similar to other studies,12, 19 our findings indicate that influenza and Tdap vaccination prevalence was lower for women who were younger, non-Hispanic black, with a lower level of education, uninsured, had Medicaid insurance coverage for prenatal care, had less frequent prenatal care visits, participated in WIC during the prenatal period, and had higher number of previous live births. Also consistent with prior literature, 20,21 reasons cited for not getting an influenza vaccination among pregnant women included that they don’t normally get vaccinated, concerns about vaccine safety and effectiveness, not being worried about getting sick with influenza, and lack of provider offer or recommendation. To improve maternal immunization, the development or continued support of organized, multidisciplinary efforts are needed to address vaccine hesitancy and ensure equitable access for all pregnant women regardless of sociodemographic characteristics and healthcare coverage. Vaccine hesitancy in African American communities is thought to stem from the mistrust that has developed due to a history of racial discrimination and exploitation in the United States which continue to the present day.22 Efforts to prevent continued discrimination and exploitation as well as strategic messaging are needed to overcome this distrust in order to improve the confidence in getting any vaccine, including influenza and Tdap vaccines.
Influenza vaccination prevalence was lower among women not offered or recommended influenza vaccine by a healthcare provider. As observed previously with data from an Internet panel survey, receipt of a provider offer of vaccination is strongly associated with higher vaccination prevalence among pregnant women, for both influenza and Tdap vaccines.12 We observed differences in whether the influenza vaccine was offered or recommended by a healthcare provider for all characteristics examined. This underscores the importance of equitable provision of care by healthcare providers discussing, offering, and/or recommending influenza vaccination to all women who are pregnant or will be pregnant during influenza season. However, among women who reported that a healthcare provider offered or recommended influenza vaccine, vaccination prevalence still varied by sociodemographic characteristics, health insurance coverage, and receipt of prenatal care, highlighting the importance of addressing other factors influencing influenza vaccination beyond healthcare provider counseling.
Strengths of the study and limitations of the data
Strengths of this analysis include the use of a population-based sample of women with a recent live birth and the ability to estimate jurisdiction-level influenza and Tdap vaccination prevalence. However, our findings should be interpreted in the context of several limitations. PRAMS is a cross-sectional survey with self-reported data and subject to social desirability and recall bias. Women who receive a vaccine might be more likely to recall a conversation in which their provider offered or suggested that they get the vaccine. Additionally, the results for influenza and Tdap vaccination may only be generalizable to women whose pregnancies ended in a live birth residing in the participating jurisdictions included in the analysis. Given that the survey does not report timing of healthcare provider offer of or recommendation for influenza vaccine, we were unable to determine whether it happened prior to vaccination. Furthermore, the survey did not distinguish between an offer of or recommendation for influenza vaccine, and women were not asked whether a healthcare provider offered or recommended Tdap vaccine. Also, we are unable to determine the prevalence of influenza and Tdap vaccination by provider practice type. Last, we were unable to determine influenza vaccination prevalence by specific influenza season because the survey asks about influenza vaccination during the 12 months before delivery and does not capture the date the vaccine was received. However, all women delivering in 2019 would have been pregnant in either the 2018-2019 or 2019-2020 influenza seasons.