摘要：Objectives. Our objectives were to estimate 2009 pandemic influenza A (pH1N1) vaccination coverage among pregnant women and identify associated factors. Methods. We distributed a multimodal survey to 5341 women who gave birth between November 1, 2009, and January 31, 2010, identified by hospitals in King County, Washington State, with maternity services (n = 11). Results. Of 4205 respondents, 3233 (76.9%) reported that they had received pH1N1 vaccine during pregnancy or within 2 weeks after delivery. Women whose prenatal care provider recommended vaccine had a higher vaccination prevalence than women whose provider did not (81.5% vs 29.6%; adjusted prevalence ratio = 2.1; 95% confidence interval = 1.72, 2.58). Vaccination prevalence was lower among women who had received prenatal care from a midwife only compared with women who had received care from other providers (62.9% vs 78.8%; adjusted prevalence ratio = 0.89; 95% confidence interval = 0.83, 0.96). Conclusions. Among pregnant women in King County, pH1N1 vaccination coverage was high. To improve coverage during nonpandemic seasons, influenza vaccine should be recommended routinely by prenatal care providers and vaccination provided where prenatal care is received. Barriers to midwives providing vaccination recommendations to patients should be explored. Pregnant and early postpartum women, particularly those in the second or third trimester of pregnancy through the second week postpartum, and their infants are at increased risk for serious complications from influenza virus infection. 1–5 During the 2009 influenza A (H1N1) pandemic, pregnant women had a higher hospitalization rate than the general population and accounted for a higher than expected proportion of deaths; approximately 5% of 2009 pandemic influenza A (pH1N1)-related deaths in the United States were among pregnant women, compared with the estimated 1% of the general US population who are pregnant at any given time. 1,6–8 Likewise, infants younger than 6 months had the highest rates of pH1N1-related hospitalizations among all children during the pandemic. 9 Increased morbidity and mortality among pregnant women and their infants have been observed during previous influenza pandemics and nonpandemic influenza seasons. 10–12 Vaccination of pregnant women against influenza is recommended by the Advisory Committee on Immunization Practices (ACIP) and the American Congress of Obstetricians and Gynecologists (ACOG) to protect the mother and her newborn infant. 13,14 During the 2009 pandemic, pregnant women were one of the groups at high risk and prioritized by the Centers for Disease Control and Prevention (CDC) to receive initial supplies of pH1N1 vaccine, which started becoming available nationally on October 5. 15 However, annual vaccine uptake among pregnant women typically has been low 13,16–18 ; national vaccine coverage among pregnant women during the 2007–2008 and 2008–2009 influenza seasons was 24.2% and 11.3%, respectively. 13 Barriers to maternal influenza vaccination that have been identified include vaccine safety concerns and misperception regarding risk of influenza infection. 18–20 Beginning in September 2009, Public Health–Seattle and King County (PHSKC) implemented an enhanced vaccination strategy to increase influenza vaccination of pregnant women; PHSKC serves a population of more than 1.9 million residents, and nearly 30 000 births occur in the county each year. All 11 hospitals in the county with maternity services were requested to implement processes to ensure that all pregnant women delivering in their hospitals had access to pH1N1 vaccination. In addition, PHSKC requested that prenatal care providers (i.e., obstetricians, family practitioners, and midwives), including obstetricians in King County (KC) who typically do not vaccinate patients, recommend and administer the vaccine to their pregnant patients. All 11 hospitals complied with this request by making vaccine available through their affiliated prenatal care providers (i.e., those who deliver babies at their hospital) as soon as supplies permitted; one hospital established a hospital-based vaccination clinic that provided influenza vaccines to women planning to deliver at that hospital. Women were referred to the hospital-based clinic by prenatal care providers with obstetric privileges at that hospital and completed hospital registration as part of scheduling a vaccination appointment. The local chapter of ACOG also actively encouraged obstetricians, through e-mails and newsletters, to recommend influenza vaccination. In addition, a limited number of PHSKC vaccination clinics, located at community centers throughout the county, provided and prioritized vaccine at no cost for pregnant women of all ages. To evaluate the effectiveness of the pH1N1 vaccination strategy for pregnant women, PHSKC surveyed women in KC who were pregnant when the pH1N1 vaccine became available. The objectives of this evaluation were to estimate pH1N1 vaccination coverage among women in KC during the third trimester of pregnancy and to identify sociodemographic factors, beliefs, and practices associated with vaccination.
