Trends in Reasons for Non-Receipt of Influenza Vaccination during Pregnancy in Georgia, 2004-2011

"Examining trends in reasons for non-receipt of antenatal influenza vaccination can reflect successes related to vaccine promotion and areas for improvement. By highlighting differential impacts of the 2009/2010 H1N1 pandemic, we reveal opportunities for additional research on tailoring vaccine promotion efforts to specific types of women."

Using 8 years of data from the Georgia Pregnancy Risk Assessment and Monitoring (PRAMS) survey in the United States (US), this study identifies prevalence trends in reasons women cite for not receiving an influenza vaccination during pregnancy, determines whether these trends differ by certain maternal characteristics, and assesses any influence the 2009/2010 H1N1 pandemic may have had on the non-receipt profile.

Between 2004 and 2011, 8,300 women reported no influenza vaccination during or immediately before pregnancy. Proportions of women citing "doctor didn't mention vaccination," "in first trimester during influenza season," and "not pregnant during influenza season" decreased significantly over time (Doctor didn't mention: 48.0% vs. 27.1%, test for trend p < 0.001; in first trimester: 26.8% vs. 16.3%, test for trend p < 0.001; not influenza season: 24.2% vs. 12.7%, test for trend p = 0.001). "From a public health policy perspective these trends are positive as they likely reflect success of efforts to increase provider-patient discussions of antenatal influenza vaccination and awareness of the vaccine's safety."

However, safety concerns increased over 2004 proportions in 2010 (concern about side effects for me: 40.2% vs. 28.5%, prevalence ratio (PR): 1.41, 95% confidence interval (CI): 1.16, 1.71; concern about harming my baby: 38.9% vs. 31.0%, PR = 1.26, 95% CI: 1.04, 1.53) and 2011 (concern about side effects for me: 39.0% vs. 28.5%, PR = 1.37, 95% CI: 1.13, 1.65; concern about harming my baby: 38.8% vs. 31.0%, PR = 1.25, 95% CI: 1.04, 1.50).

Prior to the 2009/2010 H1N1 pandemic, the prevalence of citing concern about side effects for me and concern about harming the baby rarely exceeded 30%. The prevalence of each of these reasons increased significantly after the pandemic, reaching or approaching 40%. "Since the 2009/2010 H1N1 influenza pandemic prompted more obstetricians to recommend vaccination than ever before, those remaining unvaccinated were not likely to site knowledge or access-related barriers, but rather other concerns, such as those about safety." Following the pandemic, more Hispanic women cited concern about vaccination harming their baby than other women; in 2011, their concern remained elevated relative to non-Hispanic white women (63% vs. 35%; adjusted PR = 1.79, 95% CI: 1.23, 2.61). Of models exploring interactions between selected maternal characteristics and the 2009/2010 H1N1 pandemic, only the model examining an association between insurance status and citing doctor did not mention vaccination exhibited significant interaction between insurance status and the pandemic (p = 0.005). Compared to women with at least some private health insurance, women without any insurance were more likely to cite their doctor not mentioning vaccination after the pandemic than before (Pre- vs. post-pandemic prevalences for insured women: 45% vs. 37%; pre vs. post-pandemic prevalences for women without insurance: 35% vs. 50%). "These results also imply that physicians may have refrained from promoting or offering the vaccine if they knew a woman could not afford the vaccine or they were not likely to get reimbursed for administering it. Exploring and understanding the underlying reasons for these differences will be important to developing targeted, evidence-based messaging following similar pandemic events affecting pregnant women."

Analysis of 2011 suggests that the youngest women and Non-Hispanic Asian/other women are not recalling doctors mentioning influenza vaccination. Rectifying these differences could mean calling physicians' attention to these findings, developing provider-focused interventions that improve their own knowledge of and confidence in the latest vaccine recommendations, and reiterating the importance of promoting influenza vaccination to all pregnant women regardless of demographics.

Across all years, the most frequently cited reason for non-receipt was "I don't normally get an influenza vaccine." With over one-third of the women citing this reason not citing any additional reason, delving deeper into why these women do not normally get a seasonal influenza vaccine will be an important step toward identifying effective interventions.

"Research in the arena of vaccine messaging has revealed that vaccine decisions occur within a complex societal framework, often influenced by familial opinions and broader social norms....As more targeted messages are developed or refined, they should move beyond the provision of information to take these more socio-ecological influences into account."