Acceptance of vaccination during pregnancy: experience with 2009 influenza A (H1N1) in the Netherlands

Objectives

In 2009, the Dutch government advised pregnant women to get vaccinated against influenza A (H1N1). A study was set up to gain insight into vaccination coverage and reasons why pregnant women seek vaccination or not.

Methods

We invited 14,529 pregnant women to complete an internet survey on vaccination during pregnancy in general and against 2009 influenza A (H1N1). Differences in background characteristics between unvaccinated and vaccinated women were investigated. Prediction analyses were carried out to determine which survey statement had the greatest impact on vaccination status or intention to get vaccinated during pregnancy.

Results

Of the 2993 included respondents, 63% reported to be vaccinated against 2009 influenza A (H1N1). Vaccination coverage was higher among older birth cohorts, women who had been pregnant before, women with underlying medical conditions, and women who reported no defined ‘life philosophy’. Protection of the child (after birth), the government's advice and possible harmful effects of the vaccine for the unborn child had the greatest predictive value for vaccination status. With regards vaccination during future pregnancies, 39% had a positive intention to obtain vaccination and 45% were neutral. The government's advice was the strongest predictor for intention. Furthermore, women expressed concern over lack of sufficient knowledge about vaccine safety.

Conclusions

A considerable number of pregnant women in the Netherlands reported to be vaccinated against 2009 influenza A (H1N1). The challenge for the government in the future will be to provide pregnant women and health care professionals with sufficient and clear information about disease severity and the benefits and safety of vaccination.     

Cross-sectional study on factors associated with influenza vaccine uptake and pertussis vaccination status among pregnant women in Germany

Pregnant women and their newborns are at increased risk for influenza-related complications; the latter also have an increased risk for pertussis-related complications. In Germany, seasonal influenza vaccination is recommended for pregnant women since 2010. A dose of pertussis-containing vaccine has been recommended since 2004 for women of childbearing age if they have not been vaccinated within the past 10 years. We conducted a nationwide cross-sectional survey among pregnant women in February/March 2013 to assess knowledge, attitudes, and practices related to influenza vaccination during pregnancy and to identify factors associated with their pertussis vaccination status. In total, 1025 pregnant women participated and provided information through a self-administered questionnaire. Of these, 23.2% were vaccinated against seasonal influenza during the 2012/13 season; 15.9% during their pregnancy. Major reasons for being unvaccinated (n = 686 respondents) were lack of confidence in the vaccine (60.4%) and the perception that vaccination was not necessary (40.3%). Influenza vaccination during pregnancy was independently associated with having received influenza vaccine in the previous season, having received a recommendation from a physician, a high level of vaccine-related knowledge and of perceived disease severity. In contrast, knowledge of the recommendation for regular hand-washing to prevent influenza and the perception that vaccine-related side effects were likely to occur or likely to be severe were negatively associated with vaccine uptake. Receipt of a pertussis vaccine in the past 10 years was reported by 22.5% of participants. Pertussis vaccine uptake was independently associated with living in the Eastern federal states and receiving seasonal influenza vaccination annually, while a migration background was associated with a lower uptake. To enhance vaccine uptake in pregnant women and women of childbearing age, special efforts must be undertaken to improve knowledge of both recommendations and the benefits of vaccination. Gynecologists could serve as important facilitators.     

Perinatal survival and health after maternal influenza A(H1N1)pdm09 vaccination: A cohort study of pregnancies stratified by trimester of vaccination

Large cohort studies demonstrated the safety of vaccination with the AS03 adjuvanted pandemic influenza vaccine, but data on first trimester vaccination safety are limited.We conducted a nationwide register-based retrospective cohort study in Finland, included singleton pregnancies present on 01 November 2009 and followed them from 01 November 2009 until delivery. Pregnancies with abortive outcome, pregnancies that started before 01 February 2009 and pregnancies of women, who received the AS03 adjuvanted pandemic influenza vaccine prior to the onset of pregnancy, were excluded. Our main outcome measures were hazard ratios comparing the risk of stillbirth, early neonatal death, moderately preterm birth, very preterm birth, moderately low birth weight, very low birth weight, and being small for gestational age between pregnancies exposed and unexposed to maternal influenza A(H1N1)pdm09 vaccination.The study population comprised 43,604 pregnancies; 34,241 (78.5%) women were vaccinated at some stage during pregnancy. The rates of stillbirth, early neonatal death, moderately preterm birth, and moderately low birth weight were similar between pregnant women exposed and unexposed to influenza A(H1N1)pdm09 vaccination. After adjusting for known risk factors, the relative rates were 0.90 (95% confidence interval 0.55–1.45) for very preterm birth, 0.84 (0.61–1.16) for very low birth weight, and 1.17 (0.98–1.40) for being small for gestational age. Also, in the subanalysis of 7839 women vaccinated during the first trimester, the rates did not indicate that maternal vaccination during the first trimester had any adverse impact on perinatal survival and health.The risk of adverse pregnancy outcomes was not associated with the exposure to the AS03 adjuvanted pandemic influenza vaccine. This study adds reassuring evidence on the safety of AS03 adjuvanted influenza vaccines when given in the first trimester and supports the recommendation of influenza vaccination to all pregnant women through all stages of pregnancy.     

A community-based survey on influenza and vaccination knowledge,perceptions and practices in Peru

BackgroundAlthough Peru provides safe and effective influenza vaccines free-of-charge, coverage among vaccine target groups like pregnant women and older adults remains low. To improve risk communication messages and vaccine uptake, we explored knowledge, perceptions and practices about influenza illness and vaccination.MethodsA cross-sectional, community-based survey with a three-stage cluster sampling design was conducted in three cities in Peru. We included mothers of young children, pregnant women and persons ≥65 years. Participants completed a questionnaire about knowledge, perceptions and practices about influenza illness and vaccination against influenza during the past year. Generalized linear models were used to explore factors associated with vaccination in the past year.Results624/645 (97%) mothers, 54/55 (98%) pregnant women and 622/673 (92%) older adults approached provided informed consent and were surveyed. While most mothers, pregnant women and older adults (94%, 96% and 91%, respectively) perceived influenza as a potentially serious illness, few pregnant women (13%) and older adults (34%) self-identified themselves as a target group for influenza vaccination. Only 28% of mothers, 19% pregnant women, and 27% older adults were vaccinated against influenza during the previous year. Among the participants that did not get vaccinated against influenza in the previous year, “being afraid of vaccination and its effects” was the most commonly cited barrier. Knowledge of the recommendation for annual vaccination was significantly associated with vaccination status among pregnant women (p = 0.048) and older adults (p = 0.004).ConclusionDespite a government subsidized vaccine program, vaccine utilization remained low among pregnant women and older adults, who seemed typically unaware of their status as high-risk groups targeted for vaccination. Those aware of the recommendations for annual vaccination were more likely to be vaccinated. Information campaigns addressing fears and highlighting populations at risk for severe influenza illness that are targeted for vaccination might increase vaccine coverage in Peru.     

Acceptance of pregnant women's vaccination against pertussis among French women and health professionals: PREVACOQ-1 and -2 studies

ObjectivesProtection of French young infants against pertussis only relies on their relatives’ vaccination. The alternative is vaccination of pregnant women against pertussis (cocooning strategy), but this strategy is not yet recommended in France. We assessed the acceptance of this strategy among French postpartum women and health professionals.Patients and methodsWe performed a multicenter survey in 2016 among postpartum women and health professionals (family physicians, obstetricians-gynecologists, midwives, and medical students) to determine the acceptance of anti-pertussis vaccination. We evaluated knowledge, perception, and attitude towards vaccination to identify factors associated with acceptance.ResultsQuestionnaires were completed by 52% (1208/2337) of women and 40% (694/1754) of health professionals. Seventy-seven per cent of women (95% CI: 74–79) and 93% of health professionals (95% CI: 91–95) were favorable to anti-pertussis vaccination of pregnant women. Thirty-three per cent (227/687) of health professionals believed that pertussis induced life-long immunity and 20% (136/687) of them were not aware of the cocooning strategy. In multivariate analysis, factors associated with acceptance among women were younger age, higher knowledge, having received advice during pregnancy, being vaccinated against influenza, and having never refused any vaccine; among health professionals, factors associated with acceptance were belief that inactivated vaccines are obstetrically safe, regular practice of influenza vaccination in pregnant women, pertussis cocooning strategy, and never prescribing preventive homeopathy for influenza.ConclusionVaccination of pregnant women against pertussis should be well-accepted by informed mothers and health professionals. If this strategy were to be implemented in France, efforts should be made towards adequate information.     

Factors associated with a successful expansion of influenza vaccination among pregnant women in Nicaragua

BackgroundPregnant women are at risk of severe influenza disease and are a priority group for influenza vaccination programs. Nicaragua expanded recommendations to include influenza vaccination to all pregnant women in the municipality of Managua in 2013.MethodsWe carried out a survey among 1,807 pregnant women who delivered at public hospitals in the municipality of Managua to evaluate the uptake of influenza vaccination and factors associated with vaccination.ResultsWe observed a high (71%) uptake of influenza vaccination among this population, with no differences observed by age, education or parity of the women. Having four antenatal visits and five or more visits were associated with receipt of influenza vaccination (AORs: 2.58; 95% CI: 1.15, 5.81, and 2.37; 95% CI: 1.12, 5.0, respectively). Also, receipt of influenza vaccination recommendation from a health care provider was positively associated with receipt of influenza vaccination (AOR: 14.22; 95% CI: 10.45, 19.33).ConclusionsThe successful expansion of influenza vaccination among pregnant women in the municipality of Managua may be due to ready access to free medical care and health care providers’ recommendation for vaccination at health care clinics that received influenza vaccine.     

Survey of influenza vaccine knowledge,attitudes, and beliefs among pregnant women in the 2016–17 season

ObjectivesInfluenza vaccination coverage among pregnant women in the United States is suboptimal. We surveyed women who were pregnant during the 2016–17 influenza season to assess knowledge and attitudes regarding influenza vaccination.MethodsWe identified and sampled pregnant women to include approximately equal numbers of vaccinated and unvaccinated women from strata defined by vaccination status and trimester from four integrated health systems in the Vaccine Safety Datalink (VSD). Potential participants were contacted via mail and telephone to complete a standardized survey. Characteristics and responses of women vaccinated and unvaccinated during pregnancy were compared.ResultsThe survey was completed by 510 (48%) of 1062 contacted women; 500 were included in the analysis. Vaccine receipt while pregnant was associated with primigravida status (p = 0.02), college degree (p = 0.01), employment in health care (p < 0.01), and history of routine annual influenza vaccination (p < 0.01). Among 330 vaccinated women, the primary reasons for vaccination included protection of self and baby from influenza (n = 233, 71%), and medical professional recommendation (n = 46, 14%). Multiple reasons were given for nonvaccination, but concern about ‘negative effects’ was cited most often (n = 44, 29%). Vaccinated women were significantly more likely to believe that influenza vaccines are safe and effective, and to recognize the potential for harm from influenza infection. Nearly all women reported receiving at least one influenza vaccination recommendation from a healthcare provider.ConclusionsVaccinated pregnant women were more likely to receive routine annual influenza vaccine compared to those not vaccinated. Recommendations by obstetric providers should be supplemented with efforts to encourage women of childbearing age to receive annual vaccination.     

Seasonal influenza and 2009 H1N1 influenza vaccination coverage among pregnant women--10 states, 2009-10 influenza season

Because pregnant women are at increased risk for severe disease associated with influenza infection, the American College of Obstetricians and Gynecologists and the Advisory Committee on Immunization Practices have recommended seasonal influenza vaccination for women while pregnant, regardless of trimester. In 2009, a novel strain of influenza A (H1N1) virus was identified, and pregnant women also were found to be at greater risk for influenza-related complications from this new virus. As a result, during the 2009--10 influenza season, two separate influenza vaccines were recommended to pregnant women: inactivated trivalent 2009--10 seasonal vaccine and influenza A (H1N1) 2009 monovalent vaccine. To estimate influenza vaccination coverage among pregnant women during the 2009--10 influenza season, CDC analyzed data from 10 states from the Pregnancy Risk Assessment Monitoring System (PRAMS). This report summarizes the results of that analysis, which determined that vaccination coverage for pregnant women among the 10 states combined was 50.7% for seasonal influenza and 46.6% for 2009 H1N1. In addition, women to whom vaccination was offered or recommended by their health-care provider were significantly more likely to report being vaccinated against seasonal influenza (relative risk [RR] = 3.3) and 2009 H1N1 (RR = 10.1). These results indicate substantially higher influenza vaccination coverage among pregnant women than has been reported for previous influenza seasons and support previous findings that receipt of influenza vaccination can be influenced greatly by health-care providers offering or recommending influenza vaccination.     

Failure of the vaccination campaign against A(H1N1) influenza in pregnant women in France: Results from a national survey

Background and objective

Pregnant women were a priority group for vaccination during the 2009 A(H1N1) influenza pandemic. In France, vaccination was organized in ad hoc centers. Women received vouchers by mail and were given a non-adjuvanted vaccine. Our objective was to assess the national vaccination rate among pregnant women and to determine the association of vaccination with maternal characteristics, prenatal care, and pregnancy-related health behaviors.

Method

Data came from a national representative sample of women who gave birth in March 2010 (N = 13 453) and were interviewed in the hospital before discharge; they were in the second trimester of pregnancy during the vaccination campaign. Associations between vaccination and socio-demographic and medical characteristics, region of residence, care providers, and preventive behaviors were assessed with bivariable analyses and logistic regression models.

Results

Vaccine coverage was 29.3% (95% CI: 28.6–30.1). The main reason for not being vaccinated was that women did not want this immunization (91%). In adjusted analyses, vaccination was more frequent in women who were older, employed, born in France, with a parity of 1 or 2 and specific favourable health behaviors. The adjusted odds ratio for women with a postgraduate educational level was 4.1 (95% CI: 3.5–4.8) compared to those who did not complete high school. Women with additional risk factors for complications from A(H1N1) infection had a vaccination rate similar to that of other women.

Conclusion

The vaccination campaign resulted in poor vaccination coverage, strong social inequalities, and no special protection for pregnant women at the highest risk of complications. These findings provide essential information for the organization of future vaccination campaigns.     

Prenatal maternal COVID-19 vaccination and pregnancy outcomes

BackgroundPrenatal maternal physiological changes may cause severe COVID-19 among pregnant women. The Pfizer-BioNTech COVID-19 vaccine (BNT162b2 mRNA) has been shown to be highly effective and it is recommended for individuals aged ≥16 years, including pregnant women, although the vaccine has not been tested on the latter.ObjectiveTo study the association between prenatal Pfizer-BioNTech COVID-19 vaccination, pregnancy course and outcomes.Study designA retrospective cohort study was performed, including all women who delivered between January and June 2021 at Soroka University Medical Center, the largest birth center in Israel. Excluded were women diagnosed with COVID-19 in the past, multiple gestations or unknown vaccination status. Pregnancy, delivery and newborn complications were compared between women who received 1 or 2-dose vaccines during pregnancy and unvaccinated women. Multivariable models were used to adjust for background characteristics.ResultsA total of 4,399 women participated in this study, 913 (20.8%) of which were vaccinated during pregnancy. All vaccinations occurred during second or third trimesters. As compared to the unvaccinated women, vaccinated women were older, more likely to conceive following fertility treatments, to have sufficient prenatal care, and of higher socioeconomic position. In both crude and multivariable analyses, no differences were found between the groups in pregnancy, delivery and newborn complications, including gestational age at delivery, incidence of small for gestational age and newborn respiratory complications.ConclusionsPrenatal maternal COVID-19 vaccine has no adverse effects on pregnancy course and outcomes. These findings may help pregnant women and health care providers to make informed decision regarding vaccination.     

Missed opportunities for tetanus immunization of pregnant women in Juiz de Fora, Minas Gerais, Brazil]

OBJECTIVE: To estimate the missed opportunities for tetanus vaccination and to determine the immunization coverage at the end of pregnancy in women living in the city of Juiz de Fora, which is in the state of Minas Gerais, Brazil. METHODS: A cross-sectional study was carried out of 430 women who were randomly selected from all the maternity hospitals in the city, from February through August 1996. The women were interviewed regarding prenatal care, their knowledge of tetanus, and tetanus immunization before or during the latest pregnancy. RESULTS: The age of the participants ranged from 14 to 45 years (mean = 26.4 +/- 6.9 years); 420 women lived in urban areas and 10 in rural areas. Prenatal care was from the Brazilian public Unified Health System in 69.5% of the women (299 of 430); 27.6% (119) received prenatal care through other types of providers; and 2.8% (12) did not receive prenatal care. Of the 430 participants, 352 of them (81.8%) had their prenatal care card with them during the interview; 85.6% (368) had four or more prenatal care visits. Regarding their knowledge of tetanus, 92.1% (396) knew about the disease and its severity. Out of the 430 women, 359 of them (83.5%) started the latest pregnancy without having had a tetanus vaccination; 104 were vaccinated during the latest pregnancy, so 255 had not been vaccinated by the time of delivery. This was in spite of the significant increase in the opportunities for being vaccinated with an increase in the number of prenatal visits. The odds ratio for pregnant women with four or more prenatal visits being vaccinated by the end of the pregnancy was 2.7 times that of the women with zero to three visits. Seventy percent of the opportunities for tetanus immunization were missed in the study population. The overall tetanus immunization coverage was 40.6% by the end of pregnancy. CONCLUSIONS: The low immunization coverage was below the level recommended by the World Health Organization. In combination with the high rate of missed opportunities for vaccination, this points to the need to implement a tetanus vaccination promotion strategy directed at health professionals in general but especially at those who provide care for pregnant women, in both public and private health clinics. In addition, the vaccination practices in Juiz de Fora should be strengthened.     

Knowledge,attitudes, and practices regarding seasonal influenza vaccination during pregnancy in Costa Rica: A mixed-methods study

BackgroundInfluenza increases stillbirth risk, morbidity and mortality in pregnant women. Vaccination protects pregnant women against severe disease and indirectly protects their infants, but coverage among pregnant women remains low worldwide. We aimed to describe knowledge, attitudes, and practices (KAP) regarding seasonal influenza vaccination among postpartum women and prenatal care physicians in Costa Rica.MethodsWe conducted cross-sectional KAP surveys to women one to three days after childbirth at Costa Rican Social Security Fund maternity hospitals, and obstetricians and general practitioners who provided prenatal care in 2017. Principal components analysis, multiple imputation, and logistic regression were used to examine associations between influenza vaccination and demographics, prenatal care, and sources of information—separately for postpartum women and physicians. We also held two focus groups of six healthcare workers each to further describe vaccination KAP.ResultsWe surveyed 642 postpartum women and 146 physicians in maternity hospitals in five Costa Rican provinces of whom 85.5 % (95 % CI: 82.6 %-88.0 %) and 57.9 % (95 % CI: 49.6 %-65.7 %) were vaccinated for influenza, respectively. Factors associated with influenza vaccination for postpartum women included tetanus vaccination (aOR: 3.62, 95 % CI: 1.89–6.92); received vaccination recommendations from clinicians during prenatal check-ups (aOR: 3.39, 95 % CI: 2.06–5.59); had other children in household vaccinated for influenza (aOR: 2.25, 95 % CI: 1.08–4.68); and secondary/university education (aOR: 0.15–0.31) with no formal education as reference. For postpartum women, reasons for vaccination were perceived benefits for mother and infant, whereas not being offered vaccines was most cited for non-vaccination. Most prenatal care physicians recommended influenza vaccines during prenatal check-ups but believed vaccination causes flu-like symptoms.ConclusionVaccination campaigns and provisions of free vaccines effectively increased knowledge and coverage among women in Costa Rica. To improve access, women should be offered vaccines during prenatal care appointments. Educating healthcare workers about vaccine benefits for themselves and patients is needed to mitigate safety concerns.     

Knowledge,attitudes and beliefs related to seasonal influenza vaccine among pregnant women in Thailand

BackgroundIn 2009, Thailand recommended pregnant women be prioritized for influenza vaccination. Vaccine uptake among Thai pregnant women is lower than other high-risk groups.MethodsDuring December 2012–April 2013, we conducted a cross-sectional survey of a convenience sample of Thai pregnant women aged ≥15 years attending antenatal clinics at public hospitals in 8 of 77 provinces. A self-administered questionnaire covered knowledge, attitudes, and beliefs related to influenza vaccination using the Health Belief Model. We examined factors associated with willingness to be vaccinated using log-binomial regression models.ResultsThe survey was completed by 1031 (96%) of 1072 pregnant women approached. A total of 627 (61%) women had heard about influenza vaccine and were included in the analysis, of whom 262 (42%) were willing to be vaccinated, 155 (25%) had received a healthcare provider recommendation for influenza vaccination and 25 (4%) had received the influenza vaccine during the current pregnancy. In unadjusted models, high levels of perceptions of susceptibility (prevalence ratio [PR] 1.5, 95% CI 1.2–2.0), high levels of belief in the benefits of vaccination (PR 2.3, 95% CI 1.7–3.1), moderate (PR 1.7, 95% CI 1.2–2.3) and high (PR 3.4, 95% CI 2.6–4.5) levels of encouragement by others to be vaccinated (i.e., cues to action) were positively associated with willingness to be vaccinated. Moderate (PR 0.5, 95% CI 0.4–0.7) and high levels of (PR 0.5, 95% CI 0.4–0.8) perceived barriers were negatively associated with willingness to be vaccinated. In the final adjusted model, only moderate (PR 1.5, 95% CI 1.1–2.0) and high levels of cues to action (PR 2.7, 95% CI 2.0–3.6) were statistically associated with willingness to be vaccinated.ConclusionCues to action were associated with willingness to be vaccinated and can be used to inform communication strategies during the vaccine campaign to increase influenza vaccination among Thai pregnant women.     

Influenza vaccination in pregnancy: practices among obstetrician-gynecologists--United States, 2003-04 influenza season

Women infected with influenza virus during pregnancy are at increased risk for serious complications and hospitalization. During 1997-2003, the Advisory Committee on Immunization Practices (ACIP) included healthy pregnant women who would be in their second or third trimester of pregnancy during the influenza season among those persons at high risk for whom influenza vaccination was indicated. Also included were women at any stage of pregnancy with certain chronic medical conditions, such as asthma, diabetes mellitus, or heart disease. ACIP emphasized that the influenza vaccine was safe for breastfeeding mothers and their infants and that household contacts of children aged <2 years also should be vaccinated. However, despite these recommendations, only 13% of pregnant women received influenza vaccination in 2003. To assess understanding of the ACIP recommendations among obstetrician-gynecologists (OB/GYNs), the American College of Obstetricians and Gynecologists (ACOG), with support from CDC, surveyed a national sample of OB/GYNs in May 2004. This report describes the results of that survey, which indicated that 52% of OB/GYNs surveyed would recommend influenza vaccination for a healthy woman in the first trimester of pregnancy, 95% would recommend the vaccine for a healthy pregnant woman beyond the first trimester, and 63% would recommend vaccination for a woman with a medical condition in the first trimester. However, of the physicians who would recommend vaccination, 36%-38% reported that influenza vaccination was not offered in their practices. Increased efforts are needed to improve vaccine availability and to educate OB/GYNs regarding the updated ACIP recommendations on the use of influenza vaccine in the first trimester for both healthy pregnant women and pregnant women at high risk.     

Influenza vaccine for pregnant women in resource-constrained countries: a review of the evidence to inform policy decisions

Seasonal influenza is responsible for three to five million severe cases of disease annually, and up to 500,000 deaths worldwide. Pregnant women and infants suffer disproportionately from severe outcomes of influenza. The excellent safety profile and reliable immunogenicity of inactivated influenza vaccine support WHO recommendations that pregnant women be vaccinated to decrease complications of influenza disease during pregnancy. Nevertheless, influenza vaccine is not routinely used in most low-and middle-income countries and is not widely used in pregnant women worldwide.Two recent prospective, controlled trials of maternal influenza vaccination in Bangladesh and US Native American reservations demonstrated that inactivated influenza vaccine given to pregnant women can decrease laboratory-confirmed influenza virus infection in their newborn children. These studies support consideration of the feasibility of targeted influenza vaccine programs in resource-constrained countries.Platforms exist for the delivery of influenza vaccine to pregnant women worldwide. Even in the least developed countries, an estimated 70% of women receive antenatal care, providing an opportunity for targeted influenza vaccination. Challenges to the introduction of maternal influenza vaccination in resource-constrained countries exist, including issues regarding vaccine formulation, availability, and cost. Nonetheless, maternal influenza vaccination remains an important and potentially cost-effective approach to decrease influenza morbidity in two high-risk groups - pregnant women and young infants.     

Birth defects among infants born to women who received anthrax vaccine in pregnancy

In response to bioterrorism threats, anthrax vaccine has been used by the US military and considered for civilian use. Concerns exist about the potential for adverse reproductive health effects among vaccine recipients. This retrospective cohort evaluated birth defects, in relation to maternal anthrax vaccination, among all infants born to US military service women between 1998 and 2004. Department of Defense databases defined maternal vaccination and infant diagnoses; multivariable regression models described potential associations between anthrax vaccination and birth defects in liveborn infants. Among 115,169 infants born to military women during this period, 37,140 were born to women ever vaccinated against anthrax, and 3,465 were born to women vaccinated in the first trimester of pregnancy. Birth defects were slightly more common in first trimester-exposed infants (odds ratio = 1.18, 95% confidence interval: 0.997, 1.41) when compared with infants of women vaccinated outside of the first trimester, but this association was statistically significant only when alternative referent groups were used. Although the small observed association may be unlikely to represent a causal relation between vaccination in early pregnancy and birth defects, this information should be considered when making decisions about administering anthrax vaccine to pregnant women.     

Knowledge,attitudes and practices about influenza vaccination among pregnant women and healthcare providers serving pregnant women in Managua,Nicaragua

BackgroundNicaragua implemented an influenza vaccination program for pregnant women with high-risk obstetric conditions in 2007. In 2014, the recommendation of influenza vaccination expanded to include all pregnant women. Given the expansion in the recommendation of vaccination, we evaluated knowledge, attitudes and practices of pregnant women and their healthcare providers towards influenza vaccination and its recommendation.MethodsWe conducted surveys among pregnant women and their healthcare providers from June to August 2016 at two hospitals and 140 health facilities in Managua. The questions were adapted from the U.S. national CDC influenza survey and related to knowledge, attitudes and practices about influenza vaccination and barriers to vaccination. We analyzed reasons for not receiving vaccination among pregnant women as well as receipt of vaccination recommendation and offer by their healthcare providers.ResultsOf 1,303 pregnant women enrolled, 42% (5 4 5) reported receiving influenza vaccination in the 2016 season. Of those who reported not receiving vaccination, 46% indicated barriers to vaccination. Pregnant women who were vaccinated were more likely to be aware of the recommendation for vaccination and the risks of influenza illness during pregnancy and to perceive the vaccine as safe and effective, compared to unvaccinated pregnant women (p-values < 0.001). Of the 619 health workers enrolled, over 89% recalled recommending influenza vaccination to all pregnant women, regardless of obstetric risk. Of the 1,223 women who had a prenatal visit between the start date of the influenza vaccination and the time of interview, 44% recalled receiving a recommendation for influenza vaccination and 43% were offered vaccination. Vaccination rates were higher for those receiving a recommendation and offer of vaccination compared with those who received neither (95% vs 5%, p-value < 0.001).ConclusionPregnant women in Managua had positive perceptions of influenza vaccine and were receptive to receiving influenza vaccination, especially after the offer and recommendation by their healthcare providers.     

Pertussis immunisation during pregnancy: Antibody levels and the impact of booster vaccine

Pertussis (whooping cough) is a highly infectious disease caused by Bordetella pertussis. Mothers lacking adequate immunity and contracting the disease represent the biggest risk of transmission to new-borns, for which the disease is often a threat. The aim of the study was to estimate the frequency of pertussis susceptibility among pregnant women, in order to point out the need for a vaccine recall during pregnancy, and to evaluate the antibody response in already vaccinated women. A cross-sectional observational study was conducted in the blood test centre of “St. Anna” Obstetrics and Gynaecology Hospital in Turin (Piedmont, Italy). Eligibility criteria included pregnant women coming to the centre for any blood test, aged 18 or above and with gestational age between 33 and 37 weeks at the moment of the blood draw. The data collection was carried out from May 2019 to January 2020 and the concentration of anti-Pertussis Toxin (anti-PT) IgG was measured through the Enzyme-Linked Immunosorbent Assay (ELISA) technique. Two-hundred women (median age 35) were enrolled: 132 (66%) had received at least one dose of pertussis vaccine, 82 of which during pregnancy. Recently vaccinated women had significantly higher antibody titres (even 12–15 times as high) compared to those vaccinated more than 5 years before or never vaccinated at all (p < 0.0001). Moreover, 95.1% of recently vaccinated women had anti-PT IgG levels above 10 IU/ml, and 85.4% above 20 IU/ml, while the same proportions were as low as 37% and 21% (respectively) in the group of women not vaccinated in pregnancy. This study confirmed that the vaccination is greatly effective in ensuring high antibody titres in the first months after the booster vaccine, with considerable differences in anti-PT IgG compared to women vaccinated earlier or never vaccinated at all, and therefore vaccinating pregnant women against pertussis still represents a valuable strategy.     

Maternal pertussis and influenza immunization coverage and attitude of health care workers towards these recommendations in Flanders,Belgium

In Belgium, pertussis vaccination is recommended for all pregnant women in every pregnancy. Adults in close contact with young infants are equally advised to receive a pertussis containing booster dose. Maternal influenza vaccination is likewise recommended in Belgium in the second or third trimester of pregnancy, within the influenza season.A quantitative multicenter survey study has been performed between October 2014 and May 2015 in both postpartum women (N = 823, response rate = 89.2%) and health care workers (HCWs) (N = 261) to assess the coverage of both vaccines during pregnancy along with the coverage of the pertussis cocoon strategy, and to evaluate the knowledge and recommending attitude of HCWs towards the maternal vaccination strategies and the cocoon strategy among surveyed women and HCWs.Overall coverage of pertussis vaccination during pregnancy was 64.0%. Most women were vaccinated by their general practitioner (GP) (82.4%), and most often in the third trimester (74.0%) of pregnancy. Overall coverage of influenza vaccination during pregnancy was 45.0%. Again the GP administered most vaccines (67.6%); vaccines were equally administered in the second or third trimester of pregnancy. Educational level had a significant influence on both the pertussis and influenza vaccination coverage during pregnancy while working situation and parity had only an influence on the maternal pertussis vaccination coverage and country of birth only on the maternal influenza vaccination coverage.Overall, 78.4% of gynecologists and GPs recommends both maternal pertussis and influenza vaccination and 67.0% recommends both maternal vaccination strategies and the cocoon strategy. Within the group of the midwives, only 23.7% recommends both maternal pertussis and influenza vaccination and 10.5% recommends both maternal vaccination strategies and the cocoon strategy.High coverage is reached among pregnant women for pertussis and influenza vaccination. Several underserved populations of pregnant women regarding maternal immunization, are identified.     

Trajectories and individual determinants of repeated seasonal flu vaccination use over the long term using data from the French E3N cohort

Despite the implementation of incentive policies to promote seasonal flu vaccination for more than 20 years in France, the coverage of high-risk individuals remains largely insufficient. While there is extensive literature on the determinants of vaccination in a given year, it rarely considers the specificity of flu vaccination, which must be repeated every autumn to remain effective. We aim to fill this gap by focusing on the flu vaccination behavior of high-risk individuals (65 years and older, chronic diseases) over a 15-year period. Based on data from 87,820 women in the French E3N cohort, we used sequence analysis methods (localized Optimal Matching) to identify typical seasonal flu vaccination profiles based on individual trajectories from 2004 to 2018. Then, using a multinomial model, we studied the individual determinants associated with the different patterns of vaccination use identified. Sequence analysis resulted in a partition of 8 clusters, which can be summarized into 4 typical behaviors: almost half of the women get vaccinated against flu each year (43%); conversely, another important share never get vaccinated against flu (32%); some do not get vaccinated for several years and then get vaccinated every year (20%); and finally, a minor share discontinued vaccination (5%). Thus, once women start getting vaccinated they generally continue every year. Nonetheless, this is a double-edged sword, as an important share of women considered at risk refrain from being vaccinated for more than a decade. Determinants associated with regular vaccination are being more at risk (age, weight, and chronic diseases), being in contact with physicians, being more educated, being in couple, having children, not smoking, and undergoing breast cancer screening.