Influenza vaccination in pregnancy: current evidence and selected national policies

Influenza vaccine during pregnancy, recommendations from healthcare providers, and race/ethnicity in the United States

OBJECTIVES

We examined racial/ethnic differences in the association between influenza vaccine recommendations from healthcare providers and maternal vaccination uptake.

METHODS

This cross-sectional study examined data from the Pregnancy Risk Assessment Monitoring System. We categorized respondents as non-Hispanic (NH) Whites, NH-Blacks, NH-Asians, American Indians/Alaska Natives, NH Other non-Whites, and Hispanics. We conducted multivariable logistical regression models to evaluate adjusted odds ratios (AOR) and 95% confidence intervals (CI). Covariates included maternal age, marital status, education, insurance status before pregnancy, the number of previous live births, the number of prenatal care visits, and smoking status during pregnancy.

RESULTS

The prevalences of receiving influenza vaccine recommendations from healthcare providers and maternal vaccine were 80.01% and 50.42%, respectively. NH-Blacks are less likely to receive provider recommendations (AOR = 0.82; 95%CI 0.77-0.87) and be vaccinated (AOR = 0.76; 95%CI 0.72-0.80) than NH-Whites. Receiving provider recommendations was significantly associated with increased maternal influenza vaccine uptake (AOR = 15.50; 95% CI 14.51-16.55). The associations were significant for all racial/ethnic groups, with the highest among NH-Asians (AOR = 22.04; 95% CI 17.88-27.16) and the lowest among NH Other non-Whites (AOR = 11.07; 95% CI 8.25-14.86). Within NH-Asians, effectiveness among Chinese was highest (AOR = 29.39; 95% CI 18.10-47.71).

CONCLUSIONS

Racial/ethnic disparities in maternal influenza vaccine uptake and receiving vaccine recommendations from healthcare providers persisted. Further studies on the racial/ethnic disparities in maternal vaccination were warranted and tailored strategies are required to reduce this health disparity.

Timing of pertussis vaccination during pregnancy: Evidence and implementation - A systematic review

BACKGROUND

Pertussis vaccination in pregnancy has been introduced in an increasing number of countries to better protect infants against the disease in their first weeks of life. The optimal timing of pertussis vaccination in pregnancy is however still under debate.

METHODS

We systematically reviewed published literature on safety, immunogenicity and effectiveness of pertussis vaccination in pregnancy related to timing of vaccination. The search was conducted using PubMed, MEDLINE and Web of Science and yielded 1623 articles, thereof 777 duplicates. Screening resulted in the inclusion of 45 publications reporting on safety (n = 11), immunogenicity (n = 26) and/or effectiveness (n = 9). We also mapped pertussis recommendations in pregnancy by government institutions globally according to the recommended timing of vaccination.

RESULTS

Overall, the selected publications did not indicate increased safety concerns associated with timing of pertussis vaccination in pregnancy. Immunogenicity studies often suggested optimal protection at birth after early third trimester vaccination. Few studies investigated qualitative antibody characteristics, and none investigated antibody titers in breastmilk or cellular-mediated immunity related to timing of vaccination. Effectiveness studies showed decreased vaccine effectiveness of late third trimester pertussis vaccination compared to vaccination earlier in pregnancy. Worldwide, a general recommendation for pertussis vaccination in pregnancy was found for 58 countries, with as many as 22 different recommended timings registered.

CONCLUSION

The timing of pertussis vaccination in pregnancy seems to impact immunogenicity and vaccine effectiveness, with optimal immune responses at birth suggested following early third trimester vaccination and reduced vaccine effectiveness of late third trimester pertussis vaccination suggested compared to vaccination earlier in pregnancy. However, inconsistent and lacking data are reflected in the divergent national recommendations for pertussis vaccination in pregnancy worldwide.

SUMMARY

Pertussis vaccination in pregnancy aims to protect infants in their first weeks of life. Our review suggests that immunogenicity and vaccine effectiveness are impacted by the timing of vaccination in pregnancy. National recommendations for pertussis vaccination in pregnancy vary widely worldwide.

[Evaluation of a community-based intervention to increase influenza vaccination coverage in pregnant women]

OBJECTIVE

To know the impact of the educational intervention carried out on the professionals of a basic health area and their community participation group, which make up the intervention group (IG), and to analyze its repercussion on the vaccination coverage achieved for influenza in the risk group (pregnant and puerperal women) comparing it with its neighboring basic zone, which makes up the control group (CG), during the 2019/20 vaccination season.

DESIGN

Quasi-experimental study of community intervention. SITE: Two basic health zones belonging to the Elche-Crevillente health department, Spain.

PARTICIPANTS

Pregnant and postpartum women from 2 basic health areas and the community participation group. Health professionals directly related to the flu vaccination campaign.

INTERVENTIONS

Training session for the IG prior to the 2019/20 flu campaign.

MAIN MEASUREMENTS

Attitudes towards influenza vaccination in health professionals through the validated CAPSVA questionnaire and the vaccination coverage of pregnant and postpartum women through the Nominal Vaccine Registry and their acceptance of the vaccine in the midwife's office.

RESULTS

The influenza vaccination coverage data recorded in Nominal Vaccine Registry for pregnant and puerperal women was 26.4% (n=207) in the IG and 19.7% (n=144) in the CG (p=0.001), with an incidence ratio of 1.34, thus achieving 34% more vaccination in the IG. Acceptance for vaccination in the midwife's office was also high, with 96.5% immunization in IG vs. 89.0% in CG, with a RR=1.09 (95% CI 1.01-1.62).

CONCLUSIONS

Joint training strategies for professionals and community assets improve the results of vaccination coverage.

The Effect of Being Pregnant during Respiratory Pandemics: A Comparison between 2009/10 Flu and 2020/21 COVID-19 Pandemic in Brazil

Pregnant women undergo physiological changes that make them a challenging group of patients during pandemic respiratory diseases, as previously found during H1N1 2009 pandemic and recently ratified in COVID-19 pandemic. We conducted a retrospective cohort analysis on 5888 hospitalized women for H1N1 flu pandemic (2190 pregnant and 3698 non-pregnant) and 64,515 hospitalized women for COVID-19 pandemic (5151 pregnant and 59,364 non-pregnant), from the Brazilian national database, to compare demographic profile, clinical aspects, and mortality in childbearing aged women during both pandemics. Additionally, the effect of being pregnant was compared between both pandemics. In both pandemics, pregnant women were younger than non-pregnant women. Overall, pregnant women had lower frequencies of comorbidities and were less symptomatic. Among hospitalized women, pregnant women presented lower mortality rates than non-pregnant women (9.7% vs. 12.6%, p = 0.002 in the H1N1 pandemic and 9.7% vs. 17.4%, p < 0.001 in the COVID-19 pandemic) and this difference was statistically more pronounced in the COVID-19 pandemic, even after balancing pregnant and non-pregnant groups regarding age and chronic diseases.

Understanding the relationship between social determinants of health and maternal mortality: Scientific Impact Paper No. 67

Within this document we use the terms pregnant woman and women's health. However, it is important to acknowledge that it is not only people who identify as women for whom it is necessary to access care. Obstetric and gynaecology services and delivery of care must therefore be appropriate, inclusive and sensitive to the needs of those individuals whose gender identity does not align with the sex they were assigned at birth.

Community pharmacists workforce readiness to deliver vaccination services: A cross-sectional study from Jordan

This study assesses Jordanian community pharmacists’ readiness and willingness to deliver vaccination services in their practice sites. Between February and April 2021, a self‐administered online questionnaire was distributed via social media, WhatsApp messages, and personal communication. The questionnaire targeted practicing community pharmacies. Descriptive and inferential data analysis was carried out. A total of 403 community pharmacists participated in the study. Almost 146 (36%) community pharmacists reported vaccinating patients in their practice sites. However, readiness assessment revealed that only 54 (13.4%) pharmacists received the required training and qualifications. Moreover, 33 (8.2%) study participants worked in adequately equipped and designed community pharmacies. Overall, surveyed participants held positive attitudes toward their involvement in vaccination services: 260 (64.5%) pharmacists were willing to vaccinate patients, and 227 (65.0%) out of unready, unqualified, participants were willing to get needed training and qualifications. According to study participants, regulatory and professional bodies (Ministry of Health, Jordan Pharmacists Association) are influential in supporting pharmacist‐vaccinators. Among the investigated factors, organizational structure and employment status were significantly associated with pharmacists’ readiness to deliver vaccination. This study revealed that further work is needed to increase pharmacists’ and pharmacies’ readiness to deliver vaccination services and that regulators should follow a more active approach in highlighting the importance of training and the impact of training in patients’ safety and satisfaction.

Educational Interventions on Pregnancy Vaccinations during Childbirth Classes Improves Vaccine Coverages among Pregnant Women in Palermo's Province

Maternal immunization is considered the best intervention in order to prevent influenza infection of pregnant women and influenza and pertussis infection of newborns. Despite the existing recommendations, vaccination coverage rates in Italy remain very low. Starting from August 2018, maternal immunization against influenza and diphtheria-tetanus-pertussis were strongly recommended by the Italian Ministry of Health. We conducted a cross sectional study to estimate the effectiveness of an educational intervention, conducted during childbirth classes in three general hospitals in the Palermo metropolitan area, Italy, on vaccination adherence during pregnancy. To this end, a questionnaire on knowledge, attitudes, and immunization practices was structured and self-administered to a sample of pregnant women attending childbirth classes. Then, an educational intervention on maternal immunization, followed by a counseling, was conducted by a Public Health medical doctor. After 30 days following the interventions, the adherence to the recommended vaccinations (influenza and pertussis) was evaluated. At the end of the study 326 women were enrolled and 201 responded to the follow-up survey. After the intervention, among the responding pregnant women 47.8% received influenza vaccination (+44.8%), 57.7% diphtheria-tetanus-pertussis vaccination (+50.7%) and 64.2% both the recommended vaccinations (+54.8%). A significant association was found between pregnant women that received at least one vaccination during pregnancy and higher educational level (graduation degree/master’s degree), employment status (employed part/full-time) and influenza vaccination adherence during past seasons (at least one during last five years). The implementation of vaccination educational interventions, including counseling by healthcare professionals (HCPs), on maternal immunization during childbirth courses improved considerably the vaccination adherence during pregnancy.

The effects of in-utero exposure to influenza on mental health and mortality risk throughout the life-course

Studies examining the later-life health consequences of in-utero exposure to influenza have typically estimated effects on physical health conditions, with little evidence of effects on mental health outcomes or mortality. Previous studies have also relied primarily on reduced-form estimates of the effects of exposure to influenza pandemics, meaning they are unlikely to recover effects of influenza exposure at an individual-level. This paper uses inverse probability of treatment weighting and "doubly-robust" methods alongside rare mother-reported data on in-utero influenza exposure to estimate the individual-level effect of in-utero influenza exposure on mental health and mortality risk throughout childhood and adulthood. We find that in-utero exposure to influenza is associated with small reductions in mental health in mid-childhood, driven by increases in internalising symptoms, and increases in depressive symptoms in mid-life for males. There is also evidence that in-utero influenza exposure is associated with substantial increases in mortality, although these effects are primarily driven by a 75% increase in the probability of being stillborn, with limited evidence of additional survival disadvantages at later ages. The potential for mortality selection implies that estimated effects on mental health outcomes are likely to represent a lower bound.

Comprehensive Overview of Vaccination during Pregnancy in Europe

Vaccinations during pregnancy can protect the mother from several infections, thus blocking vertical transmission. Furthermore, through passive antibody transfer, the newborn can be protected against some infections in the first months of life until their own vaccination regimen is initiated and completed at the appropriate age. Pregnancy can be considered a high-risk condition that increases vulnerability to infectious diseases with potentially unfavorable evolution. We present the current knowledge on vaccination during pregnancy in Europe as a useful information source for different health workers involved in prenatal care. Many European countries implement vaccination policies specifically designed for pregnant women, but there is great heterogeneity among programs. Recommendations on vaccination during pregnancy must be based on current high-quality scientific data. The decisions must be made for each individual case, depending on the associated conditions or special circumstances, with a concomitant assessment of the potential benefits and risks to both the pregnant patient and the fetus. Many vaccines are well-tolerated in pregnant women, with no clinically meaningful injection site reactions, systemic symptoms, or vaccine-related serious adverse events.

Safety, Immunogenicity, Efficacy and Effectiveness of Inactivated Influenza Vaccines in Healthy Pregnant Women and Children Under 5 Years: An Evidence-Based Clinical Review

Annual influenza vaccination is often recommended for pregnant women and young children to reduce the risk of severe influenza. However, most studies investigating the safety, immunogenicity, and efficacy or effectiveness of influenza vaccines are conducted in healthy adults. In this evidence-based clinical review, we provide an update on the safety profile, immunogenicity, and efficacy/effectiveness of inactivated influenza vaccines (IIVs) in healthy pregnant women and children <5 years old. Six electronic databases were searched until May 27, 2021. We identified 3,731 articles, of which 93 met the eligibility criteria and were included. The IIVs were generally well tolerated in pregnant women and young children, with low frequencies of adverse events following IIV administration; however, continuous vaccine safety monitoring systems are necessary to detect rare adverse events. IIVs generated good antibody responses, and the seroprotection rates after IIVs were moderate to high in pregnant women (range = 65%-96%) and young children (range = 50%-100%), varying between the different influenza types/subtypes and seasons. Studies show vaccine efficacy/effectiveness values of 50%-70% in pregnant women and 20%-90% in young children against lab-confirmed influenza, although the efficacy/effectiveness depended on the study design, host factors, vaccine type, manufacturing practices, and the antigenic match/mismatch between the influenza vaccine strains and the circulating strains. Current evidence suggests that the benefits of IIVs far outweigh the potential risks and that IIVs should be recommended for pregnant women and young children.

'My primary purpose is to protect the unborn child': Understanding pregnant women's perceptions of maternal vaccination and vaccine trials in Europe

Despite the important benefits of maternal vaccination for pregnant women and newborns, vaccination uptake is low in many European countries. Differences in vaccination policies and recommendations, as well as concerns about vaccine safety can partly explain inadequate coverage rates and women's hesitancy to get vaccinated during pregnancy. This study aims to explore pregnant women's experiences, decision-making processes and perceptions towards maternal vaccination and maternal vaccine trials in France, Germany, Italy, Spain and the United Kingdom. Qualitative interviews and focus groups were conducted with 258 pregnant women identified through local research panels and snowballing. Topic guides translated in local languages were designed to explore women's awareness and perceptions of maternal vaccination, and willingness to participate in vaccine trials during pregnancy. A thematic analysis was conducted. Pregnant women were found to have low awareness about maternal vaccination, with many reporting not having received a recommendation to vaccinate from their doctors. Strong trust in health professionals indicate that strengthened recommendations could improve vaccination uptake. Vaccination decision-making in pregnancy was described in the context of a highly emotional period, generating anxiety and fears around the safety of vaccines. Pregnancy was also discussed as a period during which women develop nurturing and protective identities. However, depending on the information they received as well as influences from experts, families and peers, women either perceived vaccination as a threat to their babies' safety or as a means to protect them. Attitudes towards maternal vaccine trials were less ambiguous, with most pregnant women strongly rejecting the notion of taking part in trials. While strategies to improve pregnant women's awareness and perceptions of maternal vaccination are needed, it is equally important to understand why healthcare professionals may not be recommending vaccination. More coordinated strategies across Europe could help strengthen communication and trust in maternal vaccination.

Trust, emotions and risks: Pregnant women's perceptions, confidence and decision-making practices around maternal vaccination in France

Maternal vaccination is an important strategy to reduce maternal and newborn mortality and morbidity. Yet, vaccination uptake is suboptimal in many countries, including France. This mixed-method study aimed to identify factors influencing maternal vaccination, exploring pregnant women's perceptions, confidence, and decision-making processes in France. Maternal vaccination uptake was positively associated with awareness of maternal vaccines, confidence in vaccine effectiveness and receiving a recommendation from a healthcare professional. A trusting relationship with healthcare professionals was observed as crucial for women during pregnancy. Even if women considered themselves as sole decision-makers, healthcare professionals' role in decision-making was viewed as substantial. Pregnancy can be a complex time for assessing risks, which was evident in the strong emotional reactions to maternal vaccination and anxieties about safety. As new maternal vaccines are developed, it is crucial to consider women's values, risk perceptions and emotions in the development of strategies to support acceptance of maternal vaccination.

The Knowledge and Perceptions of Florida Pharmacists in Administering Inactivated Influenza Vaccines to Pregnant Women

BACKGROUND

Influenza vaccine rates in pregnant women remain suboptimal despite the recommendations from healthcare organizations. Though pharmacists can provide immunization services as a result of the standing order, few studies have examined the role of the pharmacist in providing immunization to pregnant women or explored their perspective on their role in providing influenza vaccines among pregnant women.

PURPOSE

This study explored the perceptions and knowledge of Florida pharmacists in administering inactivated influenza vaccines (IIV) to pregnant women.

METHODS

Semi-structured in-depth interviews guided by the theory of planned behavior were conducted with 18 licensed Florida pharmacists, including clinical and retail pharmacists. A thematic analysis was conducted.

RESULTS

The majority of pharmacists (94%) were knowledgeable about the IIV in pregnant women. Participants expressed mixed attitudes, identified barriers and facilitators, and subjective norms influencing vaccine administration in pregnant women. Participants expressed the importance of trust and how that influenced vaccine uptake. Participants also expressed their position not to only provide immunization services but also to counsel and educate patients.

CONCLUSION

There is a need to strengthen immunization services, provided by pharmacists to more individuals, including high-risk groups such as pregnant women.

Decision-making process for introduction of maternal vaccines in Kenya, 2017-2018

BACKGROUND

Maternal immunization is a key strategy for reducing morbidity and mortality associated with infectious diseases in mothers and their newborns. Recent developments in the science and safety of maternal vaccinations have made possible development of new maternal vaccines ready for introduction in low- and middle-income countries. Decisions at the policy level remain the entry point for maternal immunization programs. We describe the policy and decision-making process in Kenya for the introduction of new vaccines, with particular emphasis on maternal vaccines, and identify opportunities to improve vaccine policy formulation and implementation process.

METHODS

We conducted 29 formal interviews with government officials and policy makers, including high-level officials at the Kenya National Immunization Technical Advisory Group, and Ministry of Health officials at national and county levels. All interviews were recorded and transcribed. We analyzed the qualitative data using NVivo 11.0 software.

RESULTS

All key informants understood the vaccine policy formulation and implementation processes, although national officials appeared more informed compared to county officials. County officials reported feeling left out of policy development. The recent health system decentralization had both positive and negative impacts on the policy process; however, the negative impacts outweighed the positive impacts. Other factors outside vaccine policy environment such as rumours, sociocultural practices, and anti-vaccine campaigns influenced the policy development and implementation process.

CONCLUSIONS

Public policy development process is complex and multifaceted by its nature. As Kenya prepares for introduction of other maternal vaccines, it is important that the identified policy gaps and challenges are addressed.

Antenatal influenza vaccination in urban Pune, India: clinician and community stakeholders' awareness, priorities, and practices

The World Health Organization (WHO) recommends antenatal influenza vaccination (AIV) for pregnant women at any stage of pregnancy. This study assessed fundamental aspects of AIV acceptance and demand among key stakeholders in urban Pune, India. Semi-structured interviews for rapid ethnographic assessment of AIV-related awareness, priorities, and practices were used to study clinicians and their communities of practice. A qualitative survey was conducted among 16 private clinicians providing antenatal care (ANC) in slum and middle-class areas of Pune. Following the survey, clinicians were informed about authoritative AIV recommendations. A qualitative community survey was also conducted with 60 women aged 20-35 years and 30 spouses from the same slum and middle-class practice areas of the ANC providers. Subsequently, a second clinician survey was conducted to assess changes in clinicians' awareness, priority, and vaccination practice. After this interview, clinicians were informed of community survey findings. Most community respondents were unaware of AIV, in contrast with well-known and widely used antenatal tetanus vaccination. They expressed confidence in vaccines and trust in the clinicians. Clinicians' advice was reportedly the most important determinant of community vaccine acceptance. Clinicians were confident of the safety of AIV and they anticipated patients' acceptance if recommended. The second clinician interview showed increased awareness of AIV policy, but clinicians were more skeptical about the severity of maternal influenza in their practice. Our findings indicate community acceptance though not demand for AIV. We recommend five essential elements for vaccination program strategies to improve coverage with AIV and other ANC vaccines.

An Assessment of Pharmacy School Curricula in Florida and Inactivated Influenza Vaccine (IIV) Administration to Pregnant Women

Background: There is a high risk for morbidity and mortality in pregnant women associated with influenza virus illness. Vaccine uptake rates in pregnant women remain lower than the targeted Healthy People 2020 goals despite recommendations from the Centers for Disease Control (CDC). Few studies have examined the role of the pharmacist in providing immunization services to pregnant women, fewer still have directly examined the PharmD curricula and the perspectives of pharmacy students on how they perceive their role in providing influenza inactivated vaccine (IIV) to pregnant women. Objective: This study examined the PharmD curricula instruction with regard to immunizing pregnant women and how pharmacy students perceive it. Methods: Semi-structured, in-depth, in-person qualitative interviews were conducted with the six Academic Deans of the accredited schools of pharmacy in Florida, and three focus group sessions were held with third- and fourth-year pharmacy students (n = 18) in Florida. A thematic analysis was conducted. Results: Most academic deans reported providing instruction on immunization in schools with respect to vaccine administration in pregnant women and called for a need for all schools to make it compulsory to include pregnant-women-specific content. Pharmacy students reported a gap in knowledge of content related to administering the IIV in pregnant women, but feel that when presented with the opportunity, they will be willing to provide IIV to pregnant women. Conclusions: Pharmacists are in a good position to play a role in increasing IIV rates among pregnant women. Implications for practice include the need for incorporation of pregnancy-specific content to immunization curricula.

Seasonal Influenza Vaccine in Pregnant Women: Views and Experiences of Obstetrician-Gynecologists

Background: Seasonal influenza vaccination rates among pregnant women remain well below the Healthy People 2020 target of 80%. Obstetrician-gynecologist (OB/GYN) recommendations are a critical means of encouraging pregnant women to get vaccinated, but there are limited data about their views. Materials and Methods: A nationally representative survey of 506 practicing OB/GYNs was completed between October 26, 2015, and May 8, 2016. Analyses included univariate distributions and comparisons based on age, size of practice, and academic affiliation using all-pairs, dependent t-tests. Results: A majority of OB/GYNs report they "strongly recommend" seasonal influenza vaccination for their pregnant patients in the first (79%) or second and third trimesters (81%). Among those who do not strongly recommend the flu vaccine in the first trimester, many say this is because of their own concerns (28%) or their patients' concerns (44%) about safety. Older OB/GYNs, those in smaller practices, and those without academic affiliation were less likely to recommend the vaccine and more likely to have safety concerns. For example, 72% of those age 60+ strongly recommended the vaccine in the second and third trimester, compared with 86% of those ages 30-44 and 83% of those ages 45-59 (p < 0.05 for all comparisons). Conclusions: OB/GYNs across the country largely support seasonal flu vaccination among pregnant women. Nonetheless, safety is a concern for them and their patients. Outreach to support clinician decisions and conversations with pregnant patients may be most needed among older physicians, those in smaller practices, and those without academic affiliation.

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.

The Protective Role of Maternal Immunization in Early Life

With birth, the newborn is transferred from a quasi-sterile environment to the outside world. At this time, the neonatal immune system is inexperienced and continuously subject to a process of development as it encounters different antigenic stimuli after birth. It is initially characterized by a bias toward T helper 2 phenotype, reduced T helper 1, and cytotoxic responses to microbial stimuli, low levels of memory, and effector T and B cells and a high production of suppressive T regulatory cells. The aim of this setting, during fetal life, is to maintain an anti-inflammatory state and immune-tolerance. Maternal antibodies are transferred during pregnancy through the placenta and, in the first weeks of life of the newborn, they represent a powerful tool for protection. Thus, optimization of vaccination in pregnancy represents an important strategy to reduce the burden of neonatal infections and sepsis. Beneficial effects of maternal immunization are universally recognized, although the optimal timing of vaccination in pregnancy remains to be defined. Interestingly, the dynamic exchange that takes place at the fetal-maternal interface allows the transfer not only of antibodies, but also of maternal antigen presenting cells, probably in order to stimulate the developing fetal immune system in a harmless way. There are still controversial effects related to maternal immunization including the so called "immunology blunting," i.e., a dampened antibody production following infant's vaccination in those infants who received placentally transferred maternal immunity. However, clinical relevance of this phenomenon is still not clear. This review will provide an overview of the evolution of the immune system in early life and discuss the benefits of maternal vaccination. Current maternal vaccination policies and their rationale will be summarized on the road to promising approaches to enhance immunity in the neonate.

COVID-19 during Pregnancy and Postpartum

Coronavirus Disease 2019 (COVID-19) triggered by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection has been declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Oxidative stress and its related metabolic syndromes are potential risk factors in the susceptibility to, and severity of COVID-19. In concert with the earliest reports of COVID-19, obstetricians started to diagnose and treat SARS-CoV-2 infections during pregnancy ("COVID-19-Pregnancy"). High metabolic demand to sustain normal fetal development increases the burden of oxidative stress in pregnancy. Intracellular redox changes intertwined with acute phase responses at the maternal-fetal interface could amplify during pregnancy. Interestingly, mother-to-fetus transmission of SARS-CoV-2 has not been detected in most of the COVID-19-Pregnancy cases. This relative absence of vertical transmission may be related to the presence of lactoferrin in the placenta, amniotic fluid, and lacteal secretions. However, the cytokine-storm induced during COVID-19-Pregnancy may cause severe inflammatory damage to the fetus, and if uncontrolled, may later result in autism spectrum-like disorders and brain development abnormalities in neonates. Considering this serious health threat to child growth and development, the prevention of COVID-19 during pregnancy should be considered a high priority. This review summarizes the intricate virulence factors of COVID-19 and elucidate its pathobiological spectrum during pregnancy and postpartum periods with a focus on the putative and complex roles of endogenous and exogenous lactoferrin in conferring immunological advantage to the host.

Immunogenicity of influenza vaccines administered to pregnant women in randomized clinical trials in Mali and South Africa

Background

A key consideration for expanding recommendations for influenza vaccination is a robust assessment of immunogenicity and efficiency of transplacental antibody transfer after maternal vaccination.

Methods

We pooled data from two trials of maternal influenza vaccination to analyze vaccine immunogenicity with more power than either trial had alone. We compared hemagglutination-inhibition (HAI) titers and titer factor change for women and their infants between trial arms using t-tests; maternal and infant putative seroprotective titers (HAI ≥ 1:40) within each trial arm and maternal seroconversion between trial arms using exact tests; and transplacental antibody transfer between trial arms using t-tests. We used marginal linear models and generalized estimating equations to examine the impact of time between maternal vaccination and delivery on transplacental antibody transfer, infant titers, and infant seroprotection.

Results

For all vaccine components (A/H1N1, A/H3N2, and Type B), >80% of vaccinated women had seroprotective titers, >60% of them seroconverted, and >50% of their infants were born with seroprotective titers. These immunogenicity outcomes occurred more often in vaccine recipients and their infants than in controls. No difference in efficiency of transplacental antibody transfer was observed between vaccine recipients and controls.

Conclusions

Our results provide robust support for further expansion of maternal influenza vaccination recommendations.

Clinical Trials Registration: NCT01430689 and NCT01306669.

Paradoxical long-term impact of maternal influenza infection on neonates and infants

Background

Pregnant women are at high risk of influenza-related morbidity and mortality. In addition, maternal influenza infection may lead to adverse birth outcomes. However, there is insufficient data on long-term impact of maternal influenza infection.

Methods

This study was conducted to assess the impact of maternal influenza infection on birth outcomes and long-term influence on infants by merging the Korea National Health Insurance (KNHI) claims database and National Health Screening Program for Infants and Children (NHSP-IC). Mother-offspring pairs were categorized by maternal influenza infection based on the ICD-10 code.

Results

Multivariate analysis revealed that maternal influenza infection significantly increased the risk of preterm birth (OR 1.408) and low birth weight (OR 1.198) irrespective of gestational age. The proportion of low birth weight neonates was significantly higher in influenza-infected women compared to those without influenza. However, since the fourth health screening (30–80 months after birth), the fraction of underweight was no longer different between children from influenza-infected and non-infected mothers, whereas the rates of overweight increased paradoxically in those born to mothers with influenza infection.

Conclusions

Maternal influenza infection might have long-term effects on the health of children and adolescents even after infancy.

Global Perspectives on Immunization During Pregnancy and Priorities for Future Research and Development: An International Consensus Statement

Immunization during pregnancy has been recommended in an increasing number of countries. The aim of this strategy is to protect pregnant women and infants from severe infectious disease, morbidity and mortality and is currently limited to tetanus, inactivated influenza, and pertussis-containing vaccines. There have been recent advancements in the development of vaccines designed primarily for use in pregnant women (respiratory syncytial virus and group B Streptococcus vaccines). Although there is increasing evidence to support vaccination in pregnancy, important gaps in knowledge still exist and need to be addressed by future studies. This collaborative consensus paper provides a review of the current literature on immunization during pregnancy and highlights the gaps in knowledge and a consensus of priorities for future research initiatives, in order to optimize protection for both the mother and the infant.

Women's knowledge and beliefs towards vaccination for influenza during pregnancy in Turkey and underlying factors of misinformation: a single-centre cross-sectional study

OBJECTIVE

The aim of the study was to evaluate the knowledge and perceptions of the pregnant women presenting to our hospital for seasonal vaccination for influenza and to determine the factors associated with it.

METHOD

In this cross-sectional study pregnant woman presenting to our hospital between October 2018 and March 2019 were evaluated. A non-validated, well-detailed questionnaire addressing the vaccination rates, participants' perceptions about the facts behind the vaccination for influenza and the factors associated with refusal of vaccination was performed. Women's knowledge level provided by their healthcare providers was also questioned.

RESULTS

A total of 250 participants were included in the study. The average age of the patients was 28.85 ± 5.42 years (range 18-43); and the average pregnancy week was 19 ± 9.75. It was determined that 98% (n = 245) of the participants did not have any vaccinations before, and 98.8% (n = 247) did not have any vaccination during their current pregnancy. 65.2% (n = 163) of the participants did not know that the vaccination for influenza was safe in pregnancy; and 64% (n = 160) did not know that the vaccination for influenza was recommended in pregnancy. The most frequent responses given by the participants to justify their refusal for the vaccination was "my doctor was against" and "it can be harmful to my baby" (25.6% and 24%, respectively). It was determined that 98.4% (n = 246) of the participants were not recommended about the vaccination for influenza by any healthcare centres; and 92.8% (n = 232) did not receive any information on vaccination for influenza.

CONCLUSION

The knowledge of the participants on vaccination for influenza was inadequate and had misconceptions. The inadequacy of healthcare employees, government institutions and the media may have played roles in this outcome. The reasons underlying the inadequacy of the healthcare providers on vaccination for influenza may be questioned.

Immunobiology of Acute Chorioamnionitis

Acute chorioamnionitis is characterized by neutrophilic infiltration and inflammation at the maternal fetal interface. It is a relatively common complication of pregnancy and can have devastating consequences including preterm labor, maternal infections, fetal infection/inflammation, fetal lung, brain, and gastrointestinal tract injury. In this review, we will discuss current understanding of the pathogenesis, immunobiology, and mechanisms of this condition. Most commonly, acute chorioamnionitis is a result of ascending infection with relatively low-virulence organisms such as the Ureaplasma species. Furthermore, recent vaginal microbiome studies suggest that there is a link between vaginal dysbiosis, vaginal inflammation, and ascending infection. Although less common, microorganisms invading the maternal-fetal interface via hematogenous route (e.g., Zika virus, Cytomegalovirus, and Listeria) can cause placental villitis and severe fetal inflammation and injury. We will provide an overview of the knowledge gleaned from different animal models of acute chorioamnionitis and the role of different immune cells in different maternal-fetal compartments. Lastly, we will discuss how infectious agents can break the maternal tolerance of fetal allograft during pregnancy and highlight the novel future therapeutic approaches.

Current practice and attitudes towards vaccination during pregnancy: a survey of GPs across England

Background

Antenatal vaccines are commonly delivered in primary care, yet the views of GPs regarding these programmes have been neglected in research to date.

Aim

To establish the attitudes and current practice of GPs towards antenatal vaccination and their views on the optimal location for delivery of this service.

Design and setting

A multicentre online survey questionnaire.

Method

A questionnaire was sent to GPs across England between December 2018 and January 2019.

Results

The majority of 1586 responders considered antenatal vaccination safe (96% for influenza, 89% pertussis). GPs were significantly less confident in their knowledge of pertussis compared with influenza vaccination (64% versus 80% were confident, P <0.001), and many desired further education (59% versus 48%, P <0.001). Few (37%) discussed vaccination with pregnant women regularly, but most (80%) felt their recommendation would influence decision making. Those with greater confidence in their knowledge of pertussis and influenza vaccination, and who were >2 years since qualifying, discussed vaccination significantly more often (odds ratio [OR] 3.52, P <0.001; OR 2.34, P = 0.001; OR 1.76, P = 0.003, respectively), regardless of whether they routinely saw pregnant women. Most (83%) reported that antenatal vaccination was GP led in their region, yet only 26% thought it should be primarily GP based. GPs expressed disconnect from antenatal care, and many suggested that midwives and/or secondary care should take greater responsibility for the delivery of antenatal vaccination.

Conclusion

There is support among GPs to embed vaccination programmes within routine antenatal care. Further educational resources, specifically designed for the needs of GPs, are needed to facilitate opportunistic discussion with pregnant women about vaccination.

Vaccinating pregnant women against influenza needs to be a priority for all countries: An expert commentary

BACKGROUND

In 2012, the World Health Organization recommended influenza vaccination for all pregnant women worldwide and the prioritisation of pregnant women in national influenza vaccination programmes. Nevertheless, vaccination rates in pregnant women often remain much lower than national targets.

OBJECTIVES

To assess the benefits and risks associated with influenza infection and vaccination during pregnancy, and to consider obstacles that work against influenza vaccine uptake during pregnancy.

RESULTS

There is strong evidence that maternal and foetal outcomes can be compromised if women develop influenza infections during pregnancy. Influenza vaccines have been administered to millions of pregnant women and have demonstrated benefits in terms of disease prevention in mothers and their infants. There is a consensus amongst several recommending authorities that influenza vaccines may be safely administered during all stages of pregnancy. Healthcare professionals are recognised as the most important influencers of vaccine uptake, being well placed to recommend vaccination and directly address safety concerns.

CONCLUSIONS

Despite data supporting the value of influenza vaccination during pregnancy, vaccine uptake remains low globally. Low uptake appears to be largely due to ineffective communication with pregnant women about the risks and benefits of influenza vaccination. A graphical abstract is available online.

The fetal origins of mental illness

The impact of infections and inflammation during pregnancy on the developing fetal brain remains incompletely defined, with important clinical and research gaps. Although the classic infectious TORCH pathogens (ie, Toxoplasma gondii, rubella virus, cytomegalovirus [CMV], herpes simplex virus) are known to be directly teratogenic, emerging evidence suggests that these infections represent the most extreme end of a much larger spectrum of injury. We present the accumulating evidence that prenatal exposure to a wide variety of viral and bacterial infections-or simply inflammation-may subtly alter fetal brain development, leading to neuropsychiatric consequences for the child later in life. The link between influenza infections in pregnant women and an increased risk for development of schizophrenia in their children was first described more than 30 years ago. Since then, evidence suggests that a range of infections during pregnancy may also increase risk for autism spectrum disorder and depression in the child. Subsequent studies in animal models demonstrated that both pregnancy infections and inflammation can result in direct injury to neurons and neural progenitor cells or indirect injury through activation of microglia and astrocytes, which can trigger cytokine production and oxidative stress. Infectious exposures can also alter placental serotonin production, which can perturb neurotransmitter signaling in the developing brain. Clinically, detection of these subtle injuries to the fetal brain is difficult. As the neuropsychiatric impact of perinatal infections or inflammation may not be known for decades after birth, our construct for defining teratogenic infections in pregnancy (eg, TORCH) based on congenital anomalies is insufficient to capture the full adverse impact on the child. We discuss the clinical implications of this body of evidence and how we might place greater emphasis on prevention of prenatal infections. For example, increasing uptake of the seasonal influenza vaccine is a key strategy to reduce perinatal infections and the risk for fetal brain injury. An important research gap exists in understanding how antibiotic therapy during pregnancy affects the fetal inflammatory load and how to avoid inflammation-mediated injury to the fetal brain. In summary, we discuss the current evidence and mechanisms linking infections and inflammation with the increased lifelong risk of neuropsychiatric disorders in the child, and how we might improve prenatal care to protect the fetal brain.

Seasonal influenza vaccine uptake and vaccine refusal among pregnant women in France: results from a national survey

Pregnant women and infants are at high risk for severe influenza and many countries, including France, recommend annual influenza immunization during pregnancy. We aimed to estimate influenza vaccination and refusal rates and assess associated factors among pregnant women during the 2015-16 season in France. We used data from a national representative sample of women who gave birth in March 2016 and were interviewed before hospital discharge (N = 11,752). In the multivariable analysis, robust Poisson regression models were used to study associations with maternal characteristics and prenatal care characteristics. Influenza vaccine coverage among pregnant women was 7.4% (95% confidence interval [CI]: 6.9-7.9). Only 24.9% (95% CI: 24.2-25.7) of women said that they received a care provider proposal for vaccination and 70.4% (95% CI: 68.7-72.0) of these declined it. Vaccine uptake was associated with low parity (prevalence ratio [PR] = 2.1; 95% CI: 1.4-3.2 for parity 0 vs ≥ 3), high educational level (PR = 2.5; 95% CI: 2.0-3.2), healthcare occupation during pregnancy (PR = 1.8; 95% CI: 1.5-2.1) and preexisting conditions at risk for influenza (PR = 1.7; 95% CI: 1.3-2.2). Women were more frequently vaccinated when their main care provider was a general practitioner. Multiparae women and those with medium or low educational level were significantly more likely than others to decline influenza vaccine after a provider proposal. Influenza vaccine coverage is very low in France, mainly because of infrequent care provider proposals and also frequent women's refusals. Effective interventions should be designed to promote vaccination among medical professionals and reduce vaccine hesitancy among pregnant women.

Optimal timing of influenza vaccine during pregnancy: A systematic review and meta-analysis

BACKGROUND

Pregnant women have an elevated risk of illness and hospitalisation from influenza. Pregnant women are recommended to be prioritised for influenza vaccination during any stage of pregnancy. The risk of seasonal influenza varies substantially throughout the year in temperate climates; however, there is limited knowledge of how vaccination timing during pregnancy impacts the benefits received by the mother and foetus.

OBJECTIVES

To compare antenatal vaccination timing with regard to influenza vaccine immunogenicity during pregnancy and transplacental transfer to their newborns.

METHODS

Studies were eligible for inclusion if immunogenicity to influenza vaccine was evaluated in women stratified by trimester of pregnancy. Haemagglutination inhibition (HI) titres, stratified by trimester of vaccination, had to be measured at either pre-vaccination and within one month post-vaccination, post-vaccination and at delivery in the mother, or in cord/newborn blood. Authors searched PubMed, Scopus, Web of Science and EMBASE databases from inception until June 2016 and authors of identified studies were contacted for additional data. Extracted data were tabulated and summarised via random-effect meta-analyses and qualitative methods.

RESULTS

Sixteen studies met the inclusion criteria. Meta-analyses found that compared with women vaccinated in an earlier trimester, those vaccinated in a later trimester had a greater fold increase in HI titres (1.33- to 1.96-fold) and higher HI titres in cord/newborn blood (1.21- to 1.64-fold).

CONCLUSIONS

This review provides comparative analysis of the effect of vaccination timing on maternal immunogenicity and protection of the infant that is informative and relevant to current vaccine scheduling for pregnant women.

Recent advances in the diagnosis and management of sepsis in pregnancy

Background: Maternal sepsis accounts for 11% of all maternal deaths worldwide. It is the third most common direct cause of maternal death and is a major contributor to other common causes of maternal death, such as haemorrhage and thromboembolism. Methods: This review addresses important topics, including the epidemiology, risk factors, prevention, diagnosis, care bundles and management of maternal sepsis, including antibiotic treatment, and critical care interventions such as extracorporeal membrane oxygenation. Preventative measures that have had an impact on maternal sepsis as well as future research directions are also covered in this review. Case studies of maternal sepsis which highlight key learning points relevant to all clinicians involved in the management of obstetric patients will also be presented. Results: Although, historically, maternal death from sepsis was considered to be a problem for low-income countries, severe obstetric morbidity and maternal death from sepsis are increasing in high-income countries. The global burden of maternal sepsis and the obstetric-related and patient-related risk factors and the likely sources are presented. Recent changes in definition and nomenclature are outlined, and challenges in diagnosis and identification are discussed. Conclusions: Following maternal sepsis, early diagnosis and early intervention are critical to save lives and prevent long-term adverse sequelae. Dogma surrounding critical care interventions in pregnancy is being challenged, and future research is warranted to maximise therapeutic options available for maternal septic shock.

Vaccinations during pregnancy: a call to sting into action

Safety and efficacy of vaccinations during pregnancy have been a matter of debate. In the aftermath of the 2009 H1N1 influenza pandemic, a growing body of research has emerged, which points toward the importance of adhering to influenza vaccination recommendations for pregnant women. The same applies for vaccination against pertussis. Some vaccines (e.g., live attenuated) are still contraindicated during pregnancy. However, data indicate that these vaccines do not result in fetal impairment when administered accidentally during pregnancy. In the following, we provide a review on vaccination-related safety and efficacy aspects in pregnant women, shedding some light on potential barriers that stymie vaccination uptake among pregnant women and introducing strategies to overcome these barriers.

Embedding the delivery of antenatal vaccination within routine antenatal care: a key opportunity to improve uptake

Improving the uptake of vaccination in pregnancy has been highlighted as a priority by the World Health Organisation, yet establishing the optimal location for delivery of the antenatal vaccination program remains a topic of debate internationally. In many countries, antenatal vaccines are usually delivered within Primary Care (under the lead of general practitioners [GPs] or family physicians), yet this often presents a logistic barrier to accessing vaccination, and increasing evidence demonstrates that embedding vaccination within routine antenatal care visits may significantly improve uptake. In this commentary, we discuss recent evidence to support this approach, including anonymous feedback from patients and staff at our own institution, in which a dedicated midwife-led vaccine clinic has recently been set up. Furthermore, we highlight a number of individual and institution-level barriers which would need addressing before this approach can be routinely adopted, and suggest targets for future education and research.

Health outcomes of young children born to mothers who received 2009 pandemic H1N1 influenza vaccination during pregnancy: retrospective cohort study

OBJECTIVE

To determine whether any association exists between exposure to 2009 pandemic H1N1 (pH1N1) influenza vaccination during pregnancy and negative health outcomes in early childhood.

DESIGN

Retrospective cohort study.

SETTING

Population based birth registry linked with health administrative databases in the province of Ontario, Canada.

PARTICIPANTS

All live births from November 2009 through October 2010 (n=104 249) were included, and children were followed until 5 years of age to ascertain study outcomes.

MAIN OUTCOME MEASURES

Rates of immune related (infectious diseases, asthma), non-immune related (neoplasms, sensory disorders), and non-specific morbidity outcomes (urgent or inpatient health services use, pediatric complex chronic conditions) were evaluated from birth to 5 years of age; under-5 childhood mortality was also assessed. Propensity score weighting was used to adjust hazard ratios, incidence rate ratios, and risk ratios for potential confounding.

RESULTS

Of 104 249 live births, 31 295 (30%) were exposed to pH1N1 influenza vaccination in utero. No significant associations were found with upper or lower respiratory infections, otitis media, any infectious diseases, neoplasms, sensory disorders, urgent and inpatient health services use, pediatric complex chronic conditions, or mortality. A weak association was observed between prenatal pH1N1 vaccination and increased risk of asthma (adjusted hazard ratio 1.05, 95% confidence interval 1.02 to 1.09) and decreased rates of gastrointestinal infections (adjusted incidence rate ratio 0.94, 0.91 to 0.98). These results were unchanged in sensitivity analyses accounting for any potential differential healthcare seeking behavior or access between exposure groups.

CONCLUSIONS

No associations were observed between exposure to pH1N1 influenza vaccine during pregnancy and most five year pediatric health outcomes. Residual confounding may explain the small associations observed with increased asthma and reduced gastrointestinal infections. These outcomes should be assessed in future studies.

Ontology to identify pregnant women in electronic health records: primary care sentinel network database study

Objective

To develop an ontology to identify pregnant women from computerised medical record systems with dissimilar coding systems in a primary care sentinel network.

Materials and methods

We used a three-step approach to develop our pregnancy ontology in two different coding schemata, one hierarchical and the other polyhierarchical. We developed a coding system–independent pregnancy case identification algorithm using the Royal College of General Practitioners Research and Surveillance Centre sentinel network database which held 1.8 million patients’ data drawn from 150 primary care providers. We tested the algorithm by examining individual patient records in a 10% random sample of all women aged 29 in each year from 2004 to 2016. We did an external comparison with national pregnancy data. We used χ² test to compare results obtained for the two different coding schemata.

Results

243 005 women (median age 29 years at start of pregnancy) had 405 591 pregnancies from 2004 to 2016 of which 333 689 went to term. We found no significant difference between results obtained for two populations using different coding schemata. Pregnancy mean ages did not differ significantly from national data.

Discussion

This ontologically driven algorithm enables consistent analysis across data drawn from populations using different coding schemata. It could be applied to other hierarchical coding systems (eg, International Classification of Disease) or polyhierarchical systems (eg, SNOMED CT to which our health system is currently migrating).

Conclusion

This ontological approach will improve our surveillance in particular of influenza vaccine exposure in pregnancy.

Determinants of Influenza and Pertussis Vaccination Uptake in Pregnancy: A Multicenter Questionnaire Study of Pregnant Women and Healthcare Professionals

INTRODUCTION

Uptake rates of antenatal vaccination remain suboptimal. Our aims were to determine (1) the acceptability of routine vaccination among pregnant women, (2) the confidence of maternity healthcare professionals (HCPs) discussing vaccination and (3) HCP opinion regarding the optimum healthcare site for vaccine administration.

METHODS

Separate questionnaires for pregnant women and HCPs were distributed within 4 national health service (NHS) trusts in South England (July 2017 to January 2018).

RESULTS

Responses from 314 pregnant women and 204 HCPs (18% obstetricians, 75% midwives, 7% unidentified) were analyzed. Previous/intended uptake of influenza and pertussis vaccination was 78% and 92%, respectively. The commonest reason for declining vaccination was feared side effects for their child. White British women (79%) were significantly more accepting of influenza [85% vs. 61%; odds ratio (OR) 3.25; 95% confidence interval [CI], 1.67-6.32] and pertussis vaccination (96% vs. 83%; OR 4.83; 95% CI: 1.77-13.19) compared with nonwhite British women. Among HCPs, 25% were slightly or not at all confident discussing vaccination. Obstetricians felt significantly more confident discussing pertussis vaccination than midwives (68% vs. 55% were very/moderately confident; OR 2.05; 95% CI: 1.02-4.12). Among HCPs, 53%, 25% and 16% thought vaccines should be administered in primary care (general practice), community midwifery and in hospital, respectively.

CONCLUSION

Misconceptions exist regarding safety/efficacy of antenatal vaccination, and framing information towards the child's safety may increase uptake. Education of HCPs is essential, and vaccine promotion should be incorporated into routine antenatal care, with an emphasis on women from ethnic minorities. Administration of vaccines in primary care presents logistical barriers; however, support for alternative sites appears low among HCPs.

Influenza vaccination of pregnant women: Engaging clinicians to reduce missed opportunities for vaccination

BACKGROUND

Antenatal influenza vaccination (AIV) is an effective intervention for protecting pregnant women and their newborns against influenza. Although the World Health Organization recommends AIV at any stage of pregnancy, in low- and middle-income countries, including India, it is rarely provided. Research suggests that antenatal care (ANC) provider practices explain much of this limited coverage. Our study in urban Pune, India, assessed the feasibility of a two-stage clinician-engagement strategy to reduce missed opportunities for AIV in urban private-practice ANC clinics.

METHODS

Clinicians were randomized to intervention and control groups in slum and middle-class study sites. Intervention-group clinicians (active clinicians) were assessed on vaccination-related views and practices, and were presented with authoritative AIV recommendations from global, academic and professional medical organizations. In a second meeting after a community survey, findings concerning vaccination-related views and experiences were explained to active clinicians. Assessments of community vaccination views were not provided to control-group clinicians. Both groups maintained logs of ANC clinic visit vaccination status throughout the 11-month study period to enable identification of missed and taken opportunities for vaccination. Analyses were restricted to visits of women in their third trimester without previous AIV in the current pregnancy.

RESULTS

Overall, 30 clinicians participated. After first and second interactions, active clinicians in middle-class communities vaccinated at 12.2% and 37.8%, respectively. Middle-class control clinicians vaccinated at <0.2% throughout the study. This difference in AIV taken opportunities between middle-class active and control clinics was statistically significant (p < 0.05) after first and second interactions. In slum-community sites, active clinicians' AIV activity was minimal throughout.

CONCLUSIONS

Our approach for engaging clinicians effectively reduced missed opportunities for AIV in urban middle-class settings of Pune. It may also improve maternal vaccination for other conditions. The absence of any similar effect in slum-based clinics likely reflects critical limitations of vaccine access.

Adherence and Concordance of Influenza and Pertussis Vaccination Coverage in Pregnant Women in Spain

Background: Pregnant women should receive two vaccines during pregnancy due to maternal-foetal complications and risks as well as the influenza and pertussis vaccinations. The goal was to evaluate vaccination coverage against influenza and pertussis in pregnant women, following midwife professional advice during the pregnancy follow-up; Methods: Prospective cohort study of 1017 pregnancies during the vaccination campaign in 2015⁻2016. To estimate the degree of consistency between the coverage declared by mothers and that registered in the Nominal Vaccination Registry (NVR), we used the Cohen's kappa index (k); Results: 95.4% were registered in the NVR. Vaccination coverage recorded against influenza was 64.2% (95% CI: 61.2⁻67.2), and 89.8% (95% CI: 87.9⁻91.7) against pertussis. The coverage of the pregnant women interviewed was 61.7% (95% CI: 58.1⁻67.3)) for influenza and 92.3% (95% CI: 91.4⁻95.3) for pertussis. Subsequent interviews of 67.2% of the women produced a kappa agreement index between the data obtained from interviews and those recorded in the NVR of 0.974 (IC95%: 98.0⁻99.6) for influenza, and 0.921 (IC95%: 98.1⁻99.7) for pertussis. The women identified midwives as the main source of vaccination information and advice 88.4% (IC95%: 85.8⁻90.9); Conclusions: The NVR is an effective platform for estimating immunisation coverage in pregnant women. The degree of agreement between declared vaccinations and registered vaccinations was high for both vaccines.

Influenza and pertussis vaccination in pregnancy: Portrayal in online media articles and perceptions of pregnant women and healthcare professionals

Introduction

Online media may influence women’s decision to undergo vaccination during pregnancy. The aims of this mixed-methods study were to: (1) examine the portrayal of maternal vaccination in online media and (2) establish the perceived target of vaccine protection as viewed by pregnant women and maternity healthcare professionals (HCPs).

Methods

Online media articles on maternal vaccination (published July-December 2012 or November 2015-April 2016) were identified through the London School of Hygiene & Tropical Medicine’s Vaccine Confidence Database and thematically analysed. Questionnaires for pregnant women and HCPs were distributed within four English hospitals (July 2017-January 2018).

Results

Of 203 articles identified, 60% related to pertussis vaccination, 33% to influenza and 6% both. The majority positively portrayed vaccination in pregnancy (97%), but inaccurate, negative articles persist which criticize pertussis vaccination’s safety and efficacy. Positively-worded articles about pertussis tended to focus on infant protection and highlight examples of recent cases, whereas positively-worded articles about influenza focused on maternal protection. These themes were reflected in questionnaire responses from 314 pregnant women and 204 HCPs, who perceived pertussis vaccination as protecting the baby, and influenza vaccination as protecting the mother, or mother and baby equally. A minority of the pregnant women surveyed intended to decline influenza (22%) or pertussis (8%) vaccination.

Conclusions

The majority of online articles support pertussis and influenza vaccination during pregnancy. The portrayal of pertussis vaccination as primarily benefiting the child, using real-examples, may influence its higher uptake compared with influenza. This approach should be considered by HCPs when recommending vaccination. HCPs should be prepared to provide advice to women hesitant about vaccination, including addressing any negative media, and consider educational strategies to counteract inaccurate information. Future studies should directly assess the influence of media on vaccine decision-making and establish which media platforms are typically used by pregnant women to gather information.

Exploring the risk of severe outcomes and the role of seasonal influenza vaccination in pregnant women hospitalized with confirmed influenza, Spain, 2010/11-2015/16

Based on previous observations during pandemics and seasonal epidemics, pregnant women are considered at risk of developing severe influenza outcomes after influenza infection. With the aim of preventing severe influenza illness, the World Health Organization (WHO) includes pregnant women as a target group for seasonal influenza vaccination. However, influenza vaccine uptake during pregnancy remains low in many countries, including Spain. The objectives of this study were to increase the evidence of pregnancy as a risk factor for severe influenza illness and to study the potential role of seasonal influenza vaccination in the prevention of severe outcomes in infected pregnant women. Using information from the surveillance of Severe Hospitalized Confirmed Influenza Cases (SHCIC) in Spain, from seasons 2010/11 to 2015/16, we estimated that pregnant women in our study had a relative risk of hospitalization with severe influenza nearly 7.8 times higher than non-pregnant women of reproductive age. Only 5 out of 167 pregnant women with known vaccination status in our study had been vaccinated (3.6%). Such extremely low vaccination coverage only allowed obtaining crude estimates suggesting a protective effect of the vaccine against influenza complications (ICU admission or death). Our overall results support that pregnant women could benefit from seasonal influenza vaccination, in line with national and international recommendations.

Influence of health literacy on acceptance of influenza and pertussis vaccinations: a cross-sectional study among Spanish pregnant women

OBJECTIVES

Immunisations against influenza and Bordetella pertussis infection are recommended to pregnant women in Valencia (Spain), yet vaccination rates remain low. Health literacy (HL) appears as a crucial factor in vaccination decision-making. We explored the relation between HL of pregnant women and decisions to receive influenza and pertussis immunisations.

SETTING

University hospital in Valencia (Spain).

PARTICIPANTS

119 women who gave birth at a hospital in Valencia (Spain) between November 2015 and May 2016. Women in the immediate postpartum period (more than 27 weeks of gestation), between November 2015 and May 2016 were included in the study. Women with impairments, language barriers or illiteracy which prevented completion of the questionnaires, or those who were under 18 years were excluded from enrolment.

PRIMARY AND SECONDARY OUTCOME MEASURES

HL level; influenza and pertussis immunisation rate; reasons for rejection of vaccination.

RESULTS

119 participants were included (mean age 32.3±5.5 years, 52% primiparous, 95% full-term deliveries). A higher education level was associated with Short Assessment of Health Literacy for Spanish Adults _50 (adjusted R²=0.22, p=0.014) and Newest Vital Sign (adjusted R²=0.258, p=0.001) scores. Depending on the scale, 56%-85% of participants had adequate HL. 52% (62/119) and 94% (112/119) of women received influenza and pertussis immunisation, respectively. Women rejecting influenza vaccine had a higher HL level (measured by SALHSA_50 tool) than those accepting it (Kruskal-Wallis test p=0.022). 24% of women who declined influenza vaccination felt the vaccine was unnecessary, and 23% claimed to have insufficient information.

CONCLUSIONS

Influenza vaccination rate was suboptimal in our study. Women with high HL were more likely to decline immunisation. Information from professionals needs to match patients' HL levels to reduce negative perceptions of vaccination.

Birth outcomes following immunization of pregnant women with pandemic H1N1 influenza vaccine 2009-2010

BACKGROUND

Following the H1N1 influenza pandemic in 2009, pregnant women were recommended to receive both seasonal (TIV) and H1N1 influenza vaccines. This study presents incidence of adverse birth and pregnancy outcomes among a population of pregnant women immunized with TIV and H1N1 vaccines at Kaiser Permanente Northern California during 2009-2010.

METHODS

We telephone surveyed pregnant Kaiser Permanente Northern California members to assess non-medically-attended reactions following H1N1, TIV or both vaccines during 2009-2010 (n=5365) in a separate study. Here we assessed preterm birth (<37weeks), very preterm birth (<32weeks), low birth weight (<2500 g, LBW), very low birth weight (<1500g), small for gestational age, spontaneous abortions, stillbirths and congenital anomalies among this cohort by comparing incidence and 95% confidence intervals between the following immunization groups: TIV only, H1N1 only, H1N1 prior to TIV immunization, TIV prior to H1N1 and both immunizations given at the same time.

RESULTS

Results did not vary significantly between groups. Comparing H1N1 with TIV, incidence were similar for preterm births (6.37vs 6.28/100 births), very preterm births (5.30vs 8.29/1000 births), LBW (4.19vs 2.90/100 births), very LBW (4.54vs 5.52/1000 births), small for gestational age (9.99vs 9.24/1000 births), spontaneous abortion (7.10vs 6.83/1000 pregnancies), stillbirths (7.10vs 4.57/1000 pregnancies), and congenital anomalies (2.66vs 2.43/100 births).

CONCLUSIONS

Although constrained by small sample size, complex vaccine groups, and differential vaccine availability during 2009-2010, this study found no difference in adverse birth outcomes between H1N1 vaccine and TIV.

Maternal immunization: where are we now and how to move forward?

Pregnancy and the postpartum period are associated with elevated risks to both mother and infant from infectious disease. Vaccination of pregnant women, also called maternal immunization, has the potential to protect pregnant women, foetuses and infants from several vaccine-preventable diseases. Maternal immunoglobulin G antibodies are actively transferred through the placenta to provide passive immunity to new-borns during the first months of life, until the time for infant vaccinations or until the period of greatest susceptibility has passed. Currently, inactivated influenza, tetanus, and pertussis vaccines are recommended during pregnancy in many countries, but other vaccines may also be administered to pregnant women when risk factors are present. Several new vaccines with a specific indication for use during pregnancy are under development (e.g. respiratory syncytial virus and group B streptococcus vaccines). Years of experience suggest that maternal immunization against influenza, tetanus or pertussis has an acceptable safety profile, is well tolerated, effective and confers significant benefits to pregnant women and their infants. This review describes the principles of maternal immunization and provides an update of the recent evidence regarding the use and timing of maternal immunization. Finally, the barriers preventing wider vaccination coverage and the current limitations in addressing these are also described ( Supplementary Material ). Key messages Maternal immunization gives pregnant women greater protection against infectious diseases; induces high levels of maternal antibodies that can be transferred to the foetus; and helps protect new-borns during their first months of life, until they are old enough to be vaccinated. Pregnant women and new-borns are more vulnerable to infectious diseases than the overall population; nevertheless, vaccination rates are often low in pregnant women. This review provides an update of the recent evidence regarding the use and timing of maternal immunization and describes the barriers preventing wider vaccination uptake and the current limitations in addressing these.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Impact of patient characteristics and treatment procedures on hospitalization cost and length of stay in Japanese patients with influenza: A structural equation modelling approach

OBJECTIVES

Little is known about the economic burden of influenza-related hospitalizations in Japan. This study sought to identify the factors that contribute to the total healthcare costs (THCs) associated with hospitalizations due to influenza in the Japanese population.

STUDY DESIGN

A retrospective cross-sectional database analysis study.

METHODS

A structural equation modelling approach was used to analyse a nationwide Japanese hospital claims data. This study included inpatients with at least 1 confirmed diagnosis of influenza and with a hospital stay of at least 2 days, who were admitted between April 2014 and March 2015.

RESULTS

A total of 5261 Japanese inpatients with a diagnosis of influenza were included in the final analysis. The elderly (≥65 years) and the young (≤15 years) comprised more than 85% of patients. The average length of stay (LOS) was 12.5 days, and the mean THC was 5402 US dollars (US$) per hospitalization. One additional hospital day increased the THC by 314 US$. Intensive care unit hospitalizations were linked to higher costs (+4957 US$) compared to regular hospitalizations. The biggest procedure-related cost drivers, which were also impacted by LOS, were blood transfusions (+6477 US$), tube feedings (+3501 US$) and dialysis (+2992 US$).

CONCLUSIONS

In Japan, the economic burden due to influenza-related hospitalizations for both children and the elderly is considerable and is further impacted by associated comorbidities, diagnostic tests and procedures that prolong the LOS.

Vaccines in pregnancy: The dual benefit for pregnant women and infants

Maternal immunization has the potential to reduce the burden of infectious diseases in the pregnant woman and her infant. Many countries now recommend immunization against influenza at any stage of pregnancy and against pertussis in the third trimester. Despite evidence of the safety and effectiveness of these vaccines when administered during pregnancy, uptake generally remains low for influenza and moderate for pertussis vaccine. Enhancing confidence in both immunization providers and pregnant women by increasing the evidence-base for the safety and effectiveness of vaccines during pregnancy, improving communication and access by incorporating immunization into standard models of antenatal care are likely to improve uptake. Developing a framework for implementation of vaccines for pregnant women which is cognizant of local and national cultural, epidemiological, behavioral and societal factors will enable a smooth transition and high uptake for new vaccines currently in development for pregnant women.

Improving rates of maternal immunization: Challenges and opportunities

OBJECTIVES

An increasing number of vaccines are recommended or are being developed for use during pregnancy to protect women, fetuses, and/or newborns. For vaccines that are already recommended, vaccine uptake is variable and well below desired target. We reviewed the literature related to factors that affect a healthcare provider's recommendation and a woman's willingness to be vaccinated during pregnancy.

DESIGN

A scoping review of published literature from 2005 to 2015 was undertaken and all relevant articles were abstracted, summarized, and organized thematically.

RESULTS

Barriers and facilitators were identified that either decreased or increased the likelihood of a healthcare provider offering and a pregnant woman accepting vaccination during pregnancy. Concern about the safety of vaccines given during pregnancy was the most often cited barrier among both the public and healthcare providers. Other barriers included doubt about the effectiveness of the vaccine, lack of knowledge about the burden of disease, and not feeling oneself to be at risk of the infection. Major facilitators for maternal immunization included specific safety information about the vaccine in pregnant women, strong national recommendations, and healthcare providers who both recommended and provided the vaccine to their patients. Systems barriers such as inadequate facilities and staffing, vaccine purchase and storage, and reimbursement for vaccination were also cited. Evidence-based interventions were few, and included text messaging reminders, chart reminders, and standing orders.

CONCLUSIONS

In order to have an effective vaccination program, improvements in the uptake of recommended vaccines during pregnancy are needed. A maternal immunization platform is required that normalizes vaccination practice among obstetrical care providers and is supported by basic and continuing education, communication strategy, and a broad range of research.

Feasibility of Text Message Influenza Vaccine Safety Monitoring During Pregnancy

INTRODUCTION

The feasibility and accuracy of text messaging to monitor events after influenza vaccination throughout pregnancy and the neonatal period has not been studied, but may be important for seasonal and pandemic influenza vaccines and future maternal vaccines.

METHODS

This prospective observational study was conducted during 2013-2014 and analyzed in 2015-2016. Enrolled pregnant women receiving inactivated influenza vaccination at a gestational age <20 weeks were sent text messages intermittently through participant-reported pregnancy end to request fever, health events, and neonatal outcomes. Text message response rates, Day 0-2 fever (≥100.4°F), health events, and birth/neonatal outcomes were assessed.

RESULTS

Most (80.2%, n=166) eligible women enrolled. Median gestational age was 8.9 (SD=3.9) weeks at vaccination. Response rates remained high (80.0%-95.2%). Only one Day 0-2 fever was reported. Women reported via text both pregnancy- and non-pregnancy-specific health events, not all associated with medical visits. Most pregnancy-specific events in the electronic medical record (EMR) were reported via text message. Of all enrollees, 84.9% completed the study (131 reported live birth, ten reported pregnancy loss). Two losses reported via text were not medically attended; there was one additional EMR-identified loss. Gestational age and weight at birth were similar between text message-reported and EMR-abstracted data and 95% CIs were overlapping for proportions of prematurity, low birth weight, small for gestational age, and major birth defects, as identified by text message-reported versus EMR-abstracted plus text message-reported versus EMR-abstracted data only.

CONCLUSIONS

This study demonstrated the feasibility of text messaging for influenza vaccine safety surveillance sustained throughout pregnancy. In these women receiving inactivated influenza vaccination during pregnancy, post-vaccination fever was infrequent and a typical pattern of maternal and neonatal health outcomes was observed.