Pandemic influenza vaccination during pregnancy: an investigation of vaccine uptake during the 2009/10 pandemic vaccination campaign in Great Britain

The nurse's role in a patient-centered approach for reducing COVID-19 vaccine hesitancy during pregnancy: An American Academy of Nursing consensus paper

The evidence shows that COVID-19 vaccines can reduce the risks of poor pregnancy outcomes. Yet, reluctance to vaccinate remains high in pregnant populations. In this paper, we take a precision health and patient-centered approach to vaccine hesitancy. We adopted the society-to-cells vaccine hesitancy framework to identify society, community, family, individual, and physiologic factors contributing to COVID-19 vaccine hesitancy in pregnancy. Nurses are particularly well-suited to impact the factors associated with vaccine hesitancy. Because of their proximity to the patient, nurses are positioned to provide individualized, timely health information, and clinical guidelines to assist patients with decision-making related to vaccinations. Recommendations are provided to bolster nurses' engagement in precision health and patient-centered models of care to mitigate COVID-19 vaccine hesitancy in pregnancy.

Factors Associated With Influenza Vaccination During Pregnancy: A Real-World Evidence-Based Study

Pregnant women are at increased risk of influenza-related complications. However, the rate of influenza vaccination among pregnant women in Taiwan is low. By analyzing real-world data in this study, we investigated the factors associated with influenza vaccination during pregnancy in Taiwan. This study was a cross-sectional study. We collected real-world data from 2 databases in Taiwan: the Birth Certificate Database and the National Health Insurance Research Database. The study population was pregnant between October 2014 and December 2016 in Taiwan. The multivariate logistic regression was performed to identify factors associated with influenza vaccination, including maternal sociodemographics, trimester, comorbidities, and health-care utilization. The vaccination rate of among pregnant women was 8.2%. Factors significantly associated with a high likelihood of influenza vaccination were age between 30 and 34 years (odds ratio [OR]: 1.14; 95% confidence interval [CI]: 1.10-1.19), second trimester (OR: 1.80; 95% CI: 1.75-1.85), income equal to or exceeding NT$ 38 201 (OR: 1.92; 95% CI: 1.86-1.99), hypertension (OR: 1.16; 95% CI: 1.05-1.29), cardiovascular disease (OR: 1.29; 95% CI: 1.17-1.42), autoimmune disease (OR: 1.47; 95% CI: 1.38-1.58), and chronic pulmonary disease (OR: 1.24; 95% CI: 1.18-1.31). A low level of urbanization, at least 1 hospitalization in the previous year, and the presence of pregnancy complications (eg, gestational diabetes, preeclampsia, and placenta previa) were associated with a lower likelihood rate of influenza vaccination. The influenza vaccination rate among pregnant women in Taiwan was low. Age, gestational age, income level, urbanization level, hypertension, cardiovascular disease, autoimmune disease, chronic pulmonary disease, and pregnancy complications may be associated with influenza vaccination among pregnant women.

A scoping review of the reasons for and approaches to non-uptake of pertussis and influenza vaccinations in pregnant women in the United Kingdom and Ireland

BACKGROUND

Pertussis and influenza cause significant morbidity and mortality in pregnancy and the neonatal period. Maternal vaccination in pregnancy would reduce harm, but low vaccine uptake is a concern. This scoping review aimed to understand the reasons for, and approaches, to non-uptake of pertussis and influenza vaccinations in pregnant women in the UK and Ireland.

METHODS

The inclusion criteria of this scoping review consist of pregnant women who avail of pertussis and influenza vaccines in the UK and Ireland. MEDLINE, EMBASE, Web of Science and CINAHL databases were searched in June 2021 and updated in October 2022. Searches were limited to English language reports published after 2011. We followed the Joanna Briggs Institute guidance on scoping reviews. Data were extracted and charted.

RESULTS

Five themes emerged from the literature. Acceptability, as well as organisational and awareness issues, were overarching themes regarding reasons for and approaches to non-uptake of the vaccines respectively. Other themes included healthcare professional factors, information interpretation and pregnancy-related factors.

CONCLUSIONS

Women need clear, comprehensible information, ideally provided by their healthcare professionals, in a way that is meaningful and addresses their circumstances and risk perceptions. This research will serve as a base for future work that aims behaviour science interventions at the wider pregnant population as well as the target groups that have been identified in this review.

COVID-19 Vaccine Acceptance During Pregnancy, Women's Views, and Influencing Factors

BACKGROUND

COVID-19 vaccination is advised for pregnant women all over the world; however, vaccine acceptance is variable across the globe.

METHODS

This study was conducted by enrolling 292 antenatal women attending the outpatient department (OPD) in a tertiary care hospital in Delhi, India, between August 1, 2022 and October 31, 2022, with the aim to determine the acceptability of vaccination against COVID-19 disease in pregnancy, women's views regarding the vaccine and to ascertain reasons for acceptance or denial during pregnancy.

RESULT

Of the 292 pregnant women who completed the questionnaire, 39.73% had received both doses of vaccination against COVID-19 disease before pregnancy, and 39.04% had received a single dose. Twenty-one percent of women did not receive any vaccine. Eighty-four percent of the unvaccinated and 35% of the women with a single dose of the vaccine refused further doses during pregnancy. The most common concern was the fear that the vaccine might cause harm to the fetus (35.3%), followed by the fear of vaccine-related reactions (25.4%). Also, 14.6% of women feared that the vaccine might cause them to abort the ongoing pregnancy. Thirteen percent of women stated their intent to receive the vaccine after they were informed regarding its safety and requirement. No difference was found in the acceptability of the vaccine based on the educational status of women or on the monthly income of the families.

CONCLUSION

Adequate communication regarding safety information on COVID-19 vaccines is a must for pregnant women and their families to provide reassurance about the need and safety of the vaccines. It would facilitate making informed decisions and is likely to be helpful in increasing vaccine acceptance.

Hesitancy about COVID-19 vaccination among pregnant women: a cross-sectional study based on the health belief model

BACKGROUND

Pregnant women are at high risk for affliction by coronavirus disease 2019 (COVID-19). Vaccination is a main strategy to prevent and manage the COVID-19 pandemic. However, hesitancy about COVID-19 vaccination (HACV) is a major public health threat and a major barrier to herd immunity. The aim of the study was to evaluate pregnant women's HACV based on the Health Belief Model (HBM).

METHODS

This cross-sectional study was conducted in 2021-2022. Participants were 352 pregnant women selected from several healthcare centers in the north of Iran. Instruments for data collection were a demographic questionnaire, a COVID-19 Knowledge Questionnaire, a COVID-19 Health Belief Questionnaire, and a question about HACV. Logistic regression analysis was used to assess the effects of the study variables on HACV.

RESULTS

The rate of HACV was 42.61%. In the regression model, the three factors of perceived benefits (aOR: 0.700; 95% CI: 0.594 to 0.825), cues to action (aOR: 0.621; 95% CI: 0.516 to 0.574), and history of reproductive problems (aOR: 2.327; 95% CI: 0.1.262 to 4.292) had significant effects on HACV (P <  0.001).

CONCLUSION

HACV is highly prevalent among pregnant women. The perceived benefits and cues to action components of HBM have significant effects on pregnant women's HACV, while the perceived threat component has no significant effect on it. HBM is a good model to explain HACV among pregnant women. Educational interventions are necessary to improve pregnant women's awareness of the risks of COVID-19 for them and their fetus.

Understanding factors that influence the decision to be vaccinated against influenza and pertussis in pregnancy: A qualitative study

AIMS AND OBJECTIVES

To identify how pregnant women perceive pertussis and influenza and the factors that influence their decision to be vaccinated.

BACKGROUND

Suffering from influenza during pregnancy increases complications in the pregnant woman, foetus and newborn. Pertussis in children under six months of age causes severe complications. Maternal vaccination against influenza and pertussis is effective and safe. However, vaccination rates are insufficient.

DESIGN

We conducted a qualitative descriptive study, using semi-structured interviews. This research adheres to the COREQ guidelines and checklist.

METHODS

We carried out 18 semi-structured face-to-face interviews with pregnant women, using intentional sampling and thematic analysis.

RESULTS

We identified an overarching theme, 'factors that influenced participants' decision to be vaccinated or not', which was composed of four subthemes that were in turn made up of 12 categories. The factors that influenced participants' decision to be vaccinated against influenza and pertussis were related to their knowledge of and their perception of risk for these diseases. Participants perceived the risk of pertussis to be greater, and they focused their concern on the newborn. The recommendations and convictions of nurse-midwives were the most important factors encouraging vaccination. Participants trusted their nurse-midwives and most reported that they would have been vaccinated if their midwife had recommended it. Other factors were linked to lack of information, fear and concerns about economic interests.

CONCLUSIONS

The convictions and actions of the nurse-midwife in recommending vaccination to pregnant women are decisive. Strategies to improve vaccination rates should be directed to helping health professionals understand how their practice affects the final decision of pregnant women.

RELEVANCE TO CLINICAL PRACTICE

Understanding the factors that limit vaccination rates among pregnant women provides valuable information to nurse-midwives that can help to improve vaccination strategies and practices. Increased maternal vaccination rates would reduce morbidity and mortality among pregnant women and newborns.

Social determinants of pertussis and influenza vaccine uptake in pregnancy: a national cohort study in England using electronic health records

OBJECTIVE

To examine the social determinants of influenza and pertussis vaccine uptake among pregnant women in England.

DESIGN

Nationwide population-based cohort study.

SETTING

The study used anonymised primary care data from the Clinical Practice Research Datalink and linked Hospital Episode Statistics secondary care data.

PARTICIPANTS

Pregnant women eligible for pertussis (2012-2015, n=68 090) or influenza (2010/2011-2015/2016, n=152 132) vaccination in England.

MAIN OUTCOME MEASURES

Influenza and pertussis vaccine uptake.

RESULTS

Vaccine uptake was 67.3% for pertussis and 39.1% for influenza. Uptake of both vaccines varied by region, with the lowest uptakes in London and the North East. Lower vaccine uptake was associated with greater deprivation: almost 10% lower in the most deprived quintiles compared with the least deprived for influenza (34.5% vs 44.0%), and almost 20% lower for pertussis (57.7% vs 76.0%). Lower uptake for both vaccines was also associated with non-white ethnicity (lowest among women of black ethnicity), maternal age under 20 years and a greater number of children in the household. The associations between all social factors and vaccine uptake were broadly unchanged in fully adjusted models, suggesting the social determinants of uptake were largely independent of one another. Among 3111 women vaccinated against pertussis in their first eligible pregnancy and pregnant again, 1234 (40%) were not vaccinated in their second eligible pregnancy.

CONCLUSIONS

Targeting promotional campaigns to pregnant women who are younger, of non-white ethnicity, with more children, living in areas of greater deprivation or the London or North East regions, has potential to reduce vaccine-preventable disease among infants and pregnant women, and to reduce health inequalities. Vaccination promotion needs to be sustained across successive pregnancies. Further research is needed into whether the effectiveness of vaccine promotion strategies may vary according to social factors.

Incidence, risk factors and impact of seasonal influenza in pregnancy: A national cohort study

BACKGROUND

Pregnant women are particularly vulnerable to severe infection from influenza resulting in poor neonatal outcomes. The majority of evidence relates to pandemic 2009 A/H1N1 influenza. The objective of this study was to describe the characteristics and outcomes of pregnant women hospitalised with seasonal influenza.

METHODS

This national, prospective, observational cohort study used the UK Obstetric Surveillance System (UKOSS) to identify all pregnant women admitted to hospital between 01/11/2016 and 31/10/2018 with laboratory confirmed influenza at any gestation and up to two days after giving birth. These were compared to women admitted to give birth that did not have influenza. Baseline characteristics, immunization status, maternal and perinatal outcomes were compared.

RESULTS

There were 405 women admitted to hospital with laboratory confirmed influenza in pregnancy: 2.7 per 10,000 maternities. Compared to 694 comparison women, women with influenza were less likely to be professionally employed (aOR 0.59, 95%CI 0.39-0.89) or immunised in the relevant season (aOR 0·59, 0·39-0·89) and more likely to have asthma (aOR 2.42, 1.30-4.49) or have had a previous pregnancy complication (aOR 2·47, 1·33-4·61). They were more likely to be admitted to intensive care (aOR 21.3, 2.78-163.1) and to have a cesarean birth (aOR 1·42, 1·02-1.98). Their babies were more likely to be admitted to neonatal intensive care (aOR 1.86, 1·01-3·42).

CONCLUSIONS

Immunization reduces the risk of hospitalisation with influenza in pregnancy which is associated with increased risk of morbidity for both the mother and baby. There is a continued need to increase awareness of safety and effectiveness of immunization in pregnancy and provision within antenatal care settings, especially for high-risk groups.

Seasonal influenza during pregnancy

Seasonal Influenza is an acute respiratory illness caused by Influenza A or B viruses. Its presentation is commonly with signs and symptoms of upper respiratory tract involvement such as cough, sore throat and runny nose, associated with generalized systemic symptoms such as fever, headaches, myalgia, and weakness. The severity of symptoms is very variable, ranging from mild self-limiting infection to severe acute respiratory illness requiring intensive interventions. It usually occurs during the winter season and can lead to outbreaks and epidemics worldwide. Influenza is associated with increased morbidity and mortality in high-risk populations including pregnant women and up to two weeks postpartum. Rapid and accurate diagnosis of Influenza is necessary for prompt treatment to reduce morbidity. General public health measures and vaccination are recommended to reduce morbidity and control the spread of the disease. There are many published articles on the several Influenza epidemics that have occurred in this century. In this article, we aim to review the epidemiology, clinical manifestations, diagnosis, treatment, and prevention of seasonal Influenza during pregnancy. We performed an electronic search on PubMed, Cochrane database, National guidelines clearing house and Google Scholar databases.

Lessons learned from the A (H1N1) influenza pandemic

Influenza in pregnancy is a common condition that is associated with an increased risk of hospital admission. Women with comorbidities are at a greater risk of severe outcomes. There are substantial gaps in our knowledge of the impact of severe influenza on perinatal outcomes, particularly in low- and middle-income countries, but preterm birth, fetal death, infant respiratory infection and hospital admission may be increased. Thus, influenza is a major burden on health services. Immunisation is cost-effective, safe and effective in preventing influenza in pregnant women and their infants but policies and uptake vary worldwide. Operational challenges and concern over the safety, efficacy and necessity of immunisation are common, and there is a lack of evidence on how to overcome these barriers. This review identifies learning points that are relevant to the current coronavirus disease-2019 pandemic through describing the epidemiology and impact of seasonal and A(H1N1)pdm09 influenza in pregnancy, alongside the effectiveness and use of immunisation.

Vaccination against influenza among pregnant women in southern Brazil and associated factors

Abstract This article aims to identify the prevalence and factors associated with influenza vaccination in pregnant women. This is a cross-sectional study conducted in a municipality in the southernmost region of Brazil, which included all women giving birth in 2016. The outcome was having received the vaccine against influenza during pregnancy. Sociodemographic, behavioral and prenatal care characteristics and morbidities were analyzed. The analysis included sample description, the prevalence of vaccination for each independent variable and a multivariate analysis. Two thousand six hundred ninety-four pregnant women were interviewed, of which 53.9% reported having been vaccinated. Factors associated with increased prevalence of vaccination were mother’s higher schooling, prenatal care, tetanus vaccination and prenatal care performed in a public service. On the other hand, prenatal care onset after the first quarter reduced the prevalence of vaccination. The results point to the need to reinforce the importance of vaccination against influenza among pregnant women and among health professionals, regardless of the severity of the current epidemiological setting.

Methods to generate and validate a Pregnancy Register in the UK Clinical Practice Research Datalink primary care database

PURPOSE

Primary care databases are increasingly used for researching pregnancy, eg, the effects of maternal drug exposures. However, ascertaining pregnancies, their timing, and outcomes in these data is challenging. While individual studies have adopted different methods, no systematic approach to characterise all pregnancies in a primary care database has yet been published. Therefore, we developed a new algorithm to establish a Pregnancy Register in the UK Clinical Practice Research Datalink (CPRD) GOLD primary care database.

METHODS

We compiled over 4000 read and entity codes to identify pregnancy-related records among women aged 11 to 49 years in CPRD GOLD. Codes were categorised by the stage or outcome of pregnancy to facilitate delineation of pregnancy episodes. We constructed hierarchical rule systems to handle information from multiple sources. We assessed the validity of the Register to identify pregnancy outcomes by comparing our results to linked hospitalisation records and Office for National Statistics population rates.

RESULTS

Our algorithm identified 5.8 million pregnancies among 2.4 million women (January 1987-February 2018). We observed close agreement with hospitalisation data regarding completeness of pregnancy outcomes (91% sensitivity for deliveries and 77% for pregnancy losses) and their timing (median 0 days difference, interquartile range 0-2 days). Miscarriage and prematurity rates were consistent with population figures, although termination and, to a lesser extent, live birth rates were underestimated in the Register.

CONCLUSIONS

The Pregnancy Register offers huge research potential because of its large size, high completeness, and availability. Further validation work is underway to enhance this data resource and identify optimal approaches for its use.

Vaccination of pregnant women in the Valencian Community during the 2014-15 influenza season: a multicentre study

OBJECTIVE

To study influenza vaccination uptake in pregnant women from three Health Departments in the Valencian Community (Spain) during the 2014-15 flu season, to identify degree of knowledge, sources of information and attitudes toward immunization against influenza.

METHODS

Multicentre cross-sectional descriptive study during the 2014-15 vaccination campaign. Vaccine coverage was determined using the Nominal Vaccination Registry (NVR). Subsequently, a telephone survey was carried out on a sample of vaccinated and unvaccinated postpartum women.

RESULTS

The NVR had information on 934 (59.5%) out of 1,569 postpartum women; distribution per Health Departments was: 420 (44.9%), 161 (17.2%) and 353 (37.8%) in La Ribera, Torrevieja and Elx-Crevillent respectively. Vaccine uptake was 27.9% (n = 261). According to the "Country of Origin" variable, 77.5% (n = 724) of women were Spanish, with a vaccination rate of 26.7% (n = 193), compared to 22.5% (n = 210) who were non-Spanish, with a rate of 32.4% (n = 68). The main source of information was midwives for 83.7% (n = 159) of vaccinated pregnant women and for 44.6% (n = 127) of non-vaccinated women. The main reasons for vaccine refusal were lack of awareness (29.5%, n = 84) and not considering it necessary (25.6%, n = 73).

CONCLUSIONS

Despite their high willingness to be vaccinated after receiving information about the flu vaccine, the vaccination coverage in pregnant women studied is still low and can be improved. Health professionals need new information strategies to extend vaccine uptake to a larger number of pregnant women in Spain. Midwife advice plays an essential role in transmitting information on influenza vaccination in pregnant women and has a significant impact on uptake.

A population-based analysis of predictors of influenza vaccination uptake in pregnant women: The effect of gestational and calendar time

Pregnant women are vaccinated against influenza less frequently than other high-risk groups. To design effective vaccination strategies, we must understand how decisions regarding vaccination may vary by trimester and over vaccination campaigns. We used a Cox model indexed by calendar time to estimate the effect of gestational trimester and other factors on vaccination uptake in a large cohort of pregnant women in Catalonia (Spain) during 2008-09 to 2012-13 influenza vaccination campaigns. We analyzed 247,316 pregnancies. Vaccination coverage was 3.7%, 5.2%, 4.8%, 5.6% and 4.6% from 2008-09 to 2012-13 seasonal vaccination campaigns and 8.3% for the 2009 pandemic vaccination campaign. Pregnant women previously vaccinated had higher uptake than women not previously vaccinated and the hazard ratios (HRs) comparing these 2 groups decreased from 10, the first day of seasonal campaigns, to 1.3 the last day. During the pandemic campaign, HRs decreased over the course of the campaign from 8.6 to 1.9. Women in second and third trimester had higher uptake than women in first trimester, with HR=2.8 and 2.3, respectively, at the start of seasonal campaigns. Influenza vaccination coverage among this cohort of pregnant women was alarmingly low. Our analysis reveals that gestational and calendar time have distinct and interacting effects on vaccination uptake; women in their second trimester and third trimester and previously vaccinated were more prone to be vaccinated, but this effect wanes as the influenza season progresses.

Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016

BACKGROUND

Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.

OBJECTIVE

This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.

METHODS

Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.

RESULTS

Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.

CONCLUSION

Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.

Surveillance of antenatal influenza vaccination: validity of current systems and recommendations for improvement

BACKGROUND

Although influenza vaccination is recommended during pregnancy as standard of care, limited surveillance data are available for monitoring uptake. Our aim was to evaluate the validity of existing surveillance in Western Australia for measuring antenatal influenza immunisations.

METHODS

The self-reported vaccination status of 563 women who delivered between April and October 2013 was compared against three passive data collection sources: a state-wide antenatal influenza vaccination database maintained by the Department of Health, a public maternity hospital database, and a private health service database. Sensitivity, specificity, and positive and negative predictive values were calculated for each system using self-report as the "gold standard."

RESULTS

The state-wide antenatal vaccination database detected 45.7 % (95 % CI: 40.1-51.4 %) of influenza vaccinations, the public maternity hospital database detected 66.7 % (95 % CI: 55.1-76.9 %), and the private health service database detected 29.1 % (95 % CI: 20.5-39.4 %). Specificity exceeded 90 % and positive predictive values exceeded 80 % for each system. Sensitivity was lowest for women whose antenatal care was provided by a private obstetrician.

CONCLUSIONS

Existing resources for surveillance of antenatal influenza vaccinations detect 29-67 % of vaccinations. Considering the importance of influenza immunisation as a public health intervention, particularly in pregnant women, improvements to routine monitoring of influenza vaccination is warranted.

Influenza and pertussis vaccination coverage in pregnant women

BACKGROUND

Pregnant women have an increased risk for complications and hospitalizations when infected with the influenza virus in the second or third trimester. Additionally, infants under six months of age are most vulnerable when contracting pertussis. Immunization against influenza and pertussis during pregnancy provides protection for mother and neonate against influenza and for neonates against pertussis pending protection through infant immunization. In Belgium, a gradual increase in pertussis cases over the past decade was observed. This study was undertaken to document vaccination coverage for influenza and pertussis and factors related to vaccination status in pregnant women.

METHODS

Two hundred and fifty pregnant women completed a questionnaire during their third trimester. Vaccination data were collected and reasons for non-vaccination were noted as well as socio-demographic data which are known to influence vaccination coverage.

RESULTS

A documented vaccination coverage of 42.8% for influenza and 39.2% for pertussis was observed. Taking into account doses which were not documented, but administered according to the expectant mother, coverage for influenza would increase to 62% and for pertussis to 46%. The most important reasons for non-vaccination were the absence of a recommendation by medical staff (9.6%) and delay in vaccination (8.4%). The GP was the most important vaccinator. Pregnant women with a lower education and those with a foreign origin were more vulnerable for non-vaccination.

CONCLUSION

Incomplete documentation is the most important barrier in determining the vaccination status of pregnant women. Immunization during pregnancy needs further integration through vaccination campaigns aimed at both health care providers and pregnant women.

Safety of pertussis vaccination in pregnant women in UK: observational study

OBJECTIVE

To examine the safety of pertussis vaccination in pregnancy.

DESIGN

Observational cohort study.

SETTING

The UK Clinical Practice Research Datalink.

PARTICIPANTS

20,074 pregnant women with a median age of 30 who received the pertussis vaccine and a matched historical unvaccinated control group.

MAIN OUTCOME MEASURE

Adverse events identified from clinical diagnoses during pregnancy, with additional data from the matched child record identified through mother-child linkage. The primary event of interest was stillbirth (intrauterine death after 24 weeks' gestation).

RESULTS

There was no evidence of an increased risk of stillbirth in the 14 days immediately after vaccination (incidence rate ratio 0.69, 95% confidence interval 0.23 to 1.62) or later in pregnancy (0.85, 0.44 to 1.61) compared with historical national rates. Compared with a matched historical cohort of unvaccinated pregnant women, there was no evidence that vaccination accelerated the time to delivery (hazard ratio 1.00, 0.97 to 1.02). Furthermore, there was no evidence of an increased risk of stillbirth, maternal or neonatal death, pre-eclampsia or eclampsia, haemorrhage, fetal distress, uterine rupture, placenta or vasa praevia, caesarean delivery, low birth weight, or neonatal renal failure, all serious events that can occur naturally in pregnancy.

CONCLUSION

In women given pertussis vaccination in the third trimester, there is no evidence of an increased risk of any of an extensive predefined list of adverse events related to pregnancy. In particular, there was no evidence of an increased risk of stillbirth. Given the recent increases in the rate of pertussis infection and morbidity and mortality in neonates, these early data provide initial evidence for evaluating the safety of the vaccine in pregnancy for health professionals and the public and can help to inform vaccination policy making.

Determinants of uptake of influenza vaccination among pregnant women - a systematic review

BACKGROUND

Pregnant women have the highest priority for seasonal influenza vaccine. However, suboptimal coverage has been repeatedly noted in this population. To improve vaccine uptake, reviewing the determinants of vaccination is of increasing importance.

METHODS

A detailed literature search was performed up to November 30, 2013 to retrieve articles related to uptake of influenza vaccination during pregnancy.

RESULTS

Forty-five research papers were included in the review. Twenty-one studies assessed the coverage of seasonal influenza vaccination, 13 studies assessed coverage of A/H1N1 pandemic vaccination and 11 studies assessed both. Vaccination uptake ranged from 1.7% to 88.4% for seasonal influenza, and from 6.2% to 85.7% for A/H1N1 pandemic influenza. Many pregnant women were unaware that they were at high risk for influenza and its complications during pregnancy. They were also more likely to underestimate the threat of influenza to themselves and their fetus. Moreover, they had substantial concerns about the safety and efficacy of the influenza vaccine during pregnancy. Negative media reports contributed to the perception that influenza vaccination during pregnancy was risky and could result in adverse pregnancy outcomes. Although health care providers' (HCPs) recommendations were consistently associated with vaccine uptake, most did not recommend the vaccine to their pregnant clients.

CONCLUSIONS

Influenza vaccination uptake among pregnant women is suboptimal and HCPs rarely recommend it. Positive vaccination recommendations from HCPs as well as direct access to the vaccine would likely substantially improve vaccination acceptance.

2009 A/H1N1 influenza vaccination in pregnancy: uptake and pregnancy outcomes - a historical cohort study

OBJECTIVES

To describe the uptake of 2009 A/H1N1 influenza vaccination among pregnant women and determine if vaccination was associated with adverse pregnancy outcomes.

STUDY DESIGN

A historical cohort study was performed using booking, delivery suite and neonatal unit discharge records from the Coombe Women and Infants University Hospital, Dublin, Ireland. Singleton deliveries to women pregnant before (December 2008-September 2009) and during the pandemic (December 2009-September 2010) were included. Information on vaccination status and type of vaccine was collected on admission to the delivery suite. Logistic regression analyses were used to determine maternal characteristics associated with vaccination. Pregnancy outcomes were compared for vaccinated and unvaccinated women, with adjustment for differing maternal characteristics. Outcomes included vaccination status, preterm birth, size for gestational age, neonatal intensive care admission, congenital anomalies and perinatal death.

RESULTS

Of 6894 women pregnant during the pandemic, 2996 [43.5%] reported vaccination at delivery. In the early weeks of the vaccination programme rates of over 70% were achieved. Of those vaccinated, 246 [8.2%], 1709 [57.0%] and 1034 [34.5%] were vaccinated in the first, second and third trimesters respectively. Vaccination was less likely in younger age groups, those who were not in the professional/manager/employer socioeconomic group, women from Eastern Europe, Africa and Asia/Middle East, those who reported an unplanned pregnancy, women who booked late for antenatal care and recipients of publicly-funded obstetric care. Irish nationality was associated with reporting vaccination. There was no association between vaccination during pregnancy and adverse pregnancy outcomes. Women who were vaccinated were less likely to have a preterm delivery than unvaccinated women.

CONCLUSION

2009 A/H1N1 influenza vaccination uptake was influenced by maternal sociodemographic factors. High vaccination uptake can be achieved in a pandemic situation. Future public health campaigns should provide clear information on vaccination safety in pregnancy, ensure consistent vaccination recommendations from healthcare professionals and provide easy access to vaccination in order to optimise uptake rates in subgroups of the population who less likely to be vaccinated. There was no association between vaccination and adverse pregnancy outcomes.

The Clinical Practice Research Datalink for drug safety in pregnancy research: an overview

Medicine use during pregnancy is common; however the safety of medicine use during pregnancy is largely unknown when a medicine comes to market. Electronic healthcare databases, including the Clinical Practice Research Datalink (CPRD), are increasingly being used for post-marketing surveillance in this field. The CPRD contains anonymised, longitudinal medical records routinely collected in primary care. Using CPRD data it is possible to identify medical records indicative of pregnancy, including pregnancy losses. Data on prescriptions issued can be used to determine maternal exposure and for about 80% of pregnancies it is possible to link the mother's medical record to the medical record of the child. Data in the medical records of the mother and child can then be used to identify adverse pregnancy outcomes, including congenital malformations. This paper describes some of the complexities involved in using CPRD data for pregnancy related research and discusses some of its strengths and limitations.

Brief education to increase uptake of influenza vaccine among pregnant women: a study protocol for a randomized controlled trial

Background

Pregnant women are the highest priority group for annual influenza vaccination. Studies have shown unacceptably low uptake of both seasonal and pandemic A/H1N1 influenza vaccination among pregnant women. This paper will describe the study protocol and methodology of a randomised controlled trial designed to assess the effectiveness of a brief educational intervention in improving the uptake of seasonal influenza vaccine among pregnant women in Hong Kong.

Methods

A randomised controlled trial will be conducted with pregnant women in at least the second trimester of pregnancy from four publicly funded hospital antenatal clinics in Hong Kong. Participants will be randomly assigned to either one of the two treatment groups: standard care (control) or standard care plus brief education (intervention). Pregnant women in the standard care group will receive the usual antenatal care with an educational pamphlet developed by the Hong Kong Centre for Health Protection and those in the intervention group will be provided with usual care plus a brief ten-minute education intervention. Content of the education session will cover four core components recommended in the research literature. The primary study outcome will be the proportion of participants who have received influenza vaccine during their pregnancy. A total of 184 pregnant women (92 per group) will be required to give an 80% power to detect a treatment effect of 15%.

Discussion

Most intervention studies aimed at improving influenza vaccination rates in pregnant women have targeted obstetric-care providers and the results of the two patient-oriented RCT interventions are conflicting. The high priority for vaccination given to pregnant women and the low influenza vaccination rate among pregnant women worldwide strongly indicates a need for interventions to improve uptake.

Trial registration

This trial is registered with the Clinical Trials Registry at www.clinicaltrials.gov(NCT01772901).