Preparing for Group B Streptococcus vaccine. Attitudes of pregnant women in two countries.

Group B Streptococcus (GBS) vaccines, designed to be given to pregnant women, are in clinical trials. There is an opportunity to conduct preparatory research now to understand the drivers of and barriers to GBS vaccine acceptance. This will enable targeted interventions so that delays in vaccine uptake might be avoided. A multicenter, mixed-methodology, cross-sectional study evaluated the acceptability of a hypothetical GBS vaccine among pregnant women in two countries with differing health systems. Pregnant women in Philadelphia, US, and Dublin, Ireland, completed an electronic survey and a Discrete Choice Experiment. Five hundred and two women were included in the final analysis. Fifty-three percent of US and 30% of Irish participants reported both awareness and understanding of GBS. The median likelihood score for vaccine receipt (measured on a 10-point scale) was 9 (US: 9 (IQR 7-10), IRL: 9 (IQR 6-10)). Among the US participants, identifying as Black or African American was associated with a lower likelihood of vaccine receipt. Possession of a college degree was associated with increased likelihood of vaccine receipt. Perceived infant benefit was the most important driver of GBS vaccine acceptance. Safety concerns about a novel vaccine was the most prominent barrier identified. Good GBS vaccine uptake is achievable through strong messaging that highlights vaccine safety and the potential infant benefits. Preparation for vaccine implementation should include efforts to increase awareness among pregnant women about GBS infection and a continued focus on improving acceptability of currently recommended maternal vaccines, particularly in population subgroups with low uptake of maternal immunizations.

Vaccine Hesitancy in Women's Health.

The development of vaccines is considered one of the greatest breakthroughs of modern medicine, saving millions of lives around the world each year. Despite vaccines' proven success, vaccine hesitancy remains a major issue affecting vaccine uptake. Common themes exist in patients' apprehension to receive vaccines. Women's health providers possess an important role in addressing these concerns and dispelling common misconceptions that may increase vaccine hesitancy thereby reduce vaccine uptake. This review aims to explore many of these topics as they are related to women's health and provide strategies for providers to implement which may reduce vaccine hesitancy among our patients.

Levels of Neutralizing Antibodies against SARS-CoV-2 in Mothers and Neonates after Vaccination during Pregnancy.

BACKGROUND: Maternal vaccination is safe and provides protection against COVID-19 in mothers and neonates, and it is necessary to evaluate its effect on the induction of immune responses through the levels of neutralizing antibodies present in maternal and neonatal blood. METHODS: An observational study with transversal analysis was carried out. Included in the research were neonates (<1 month) whose mothers had been immunized whilst pregnant with at least one dose of the vaccine BNT16b and had not shown any symptoms of COVID-19. The blood of the mothers and newborns was collected during the Guthrie test and sent to the laboratory for the detection of neutralizing antibodies against SARS-CoV-2. RESULTS: A total of 162 pairs of mothers and neonates were analyzed with an average age of 26.3 ± 5.97 years and 13.4 ± 6.90 days, respectively. All samples collected present neutralizing antibodies with an average percentage of 91% in the mothers and 92% in the neonates. The most satisfactory immune response was observed in neonates and mothers vaccinated during the second trimester of gestation. CONCLUSIONS: The vaccination of expectant mothers with the immunizer BNT162b2 has promoted a robust immunological response in both the mothers and the neonates.

Knowledge and attitudes of pregnant women on maternal immunization against COVID-19 in Croatia.

OBJECTIVES: The aim of this study was to assess pregnant women's knowledge and attitudes regarding maternal COVID-19 immunization during pregnancy. METHODS: A cross-sectional study was performed in two teaching hospitals between May and October 2021 in Zagreb, Croatia. During antenatal clinic visit pregnant women were approached and asked to fill out a predesigned questionnaire about their knowledge and attitudes towards COVID-19 vaccination. Collected data was later analyzed. RESULTS: A total of 430 women participated in the study. Only 16% of women expressed their willingness to be vaccinated against COVID-19 if offered, despite that 71% of them believe that COVID-19 might be a serious illness in pregnant women. The most important obstacle in having better acceptance of the vaccines is in the assumption that the vaccines are not safe for pregnant women (73%) or the fetus (75%), or that the vaccines are not effective (41%). The relationship exists between acceptance of vaccination in general and willingness to get other vaccines in pregnancy and readiness to be vaccinated against COVID-19 in pregnancy. Only one out of 55 women who were not adherent to the current vaccination recommendations in Croatia would accept the COVID-19 vaccine during pregnancy if offered. 21 (5%) women stated that vaccination against influenza and pertussis during pregnancy is necessary and 13 (62%) of them would get vaccinated against COVID-19 if offered. CONCLUSIONS: This study showed that the crucial reasons for refusing vaccination against COVID-19 among pregnant women in Croatia are the concerns about the vaccines' effectiveness and safety. All healthcare providers should put more effort into education of pregnant women on risks of COVID-19, as well as on the benefits and safety of the vaccines.

COVID-19 vaccination in pregnancy.

Despite a recent endorsement from official and professional bodies unequivocally recommending COVID-19 vaccination, vaccine hesitancy among pregnant people remains high. The accumulated evidence demonstrates that pregnant people are a special risk group for COVID-19, with an increased risk of intensive care unit admission, extracorporeal membranous oxygenation requirement, preterm birth, and perinatal death. These risks are further increased with some variants of concern, and vaccination of pregnant people reduces the COVID-19-related increase in maternal or fetal morbidity. Data from more than 180,000 vaccinated persons show that immunization against COVID-19 with an mRNA vaccine is safe for pregnant people. Many observational studies comparing perinatal outcomes between vaccinated and unvaccinated pregnant people have had reassuring findings and did not demonstrate harmful effects on pregnancy or the newborn. Immunization with mRNA vaccines does not increase the risk of miscarriage, preterm delivery, low birthweight, maternal or neonatal intensive care unit admission, fetal death, fetal abnormality, or pulmonary embolism. Moreover, observational data corroborate the findings of randomized trials that mRNA vaccination is highly effective at preventing severe SARS-CoV-2 infection in pregnant people, emphasizing that the potential maternal and fetal benefits of vaccination greatly outweigh the potential risks of vaccination. Ensuring pregnant people have unrestricted access to COVID-19 vaccination should be a priority in every country worldwide.

Maternity care provider acceptance of a future Group B Streptococcus vaccine - A qualitative study in three countries.

INTRODUCTION: There are vaccines in clinical trials that target the bacterium Group B Streptococcus (GBS). When approved, GBS vaccines will be intended for administration to pregnant women to prevent infection in their infants. The success of any vaccine will depend on its' uptake in the population. Experience with prior maternal vaccines, e.g. influenza, Tdap and COVID-19 vaccines, teaches us that acceptance of vaccines, especially if novel, is challenging for pregnant women, and that provider recommendation is a key driver of vaccine uptake. METHODS: This study investigated attitudes of maternity care providers towards the introduction of a GBS vaccine in three countries (the United States (US), Ireland, and the Dominican Republic (DR)) with different GBS prevalence and prevention practices. Semi-structured interviews with maternity care providers were transcribed and coded for themes. The constant comparative method, and inductive theory building were used to develop conclusions. RESULTS: Thirty-eight obstetricians, 18 general practitioners and 14 midwives participated. There was variability in provider attitudes towards a hypothetical GBS vaccine. Responses ranged from enthusiasm to doubts over the need for a vaccine. Attitudes were influenced by perceived additional benefits of a vaccine over current strategy and confidence in the safety of vaccines during pregnancy. Knowledge, experience and approaches to GBS prevention differed geographically and according to provider type, and influenced how participants assessed the risks and benefits of a GBS vaccine. CONCLUSION: Maternity care providers are engaged in the topic of GBS management and there is opportunity to leverage attitudes and beliefs that will support a strong recommendation for a GBS vaccine. However, knowledge of GBS, and of the limitations of current prevention strategies vary among providers in different regions, and between different provider types. Targeted educational efforts with antenatal providers should focus on highlighting safety data the potential benefits of vaccination over current strategies.

Maternal vaccination-current status, challenges, and opportunities.

AIM: Maternal vaccination is a promising strategy for protecting pregnant women and newborns against severe infections. This review aims to describe the current status and challenges associated with maternal vaccination against seasonal influenza, tetanus-diphtheria-pertussis (Tdap/DTaP), and novel coronavirus disease of 2019 (COVID-19) in Japan and other countries, mainly the United States and the United Kingdom. METHODS: A literature search was conducted in PubMed and other public websites (e.g., Centers for Disease Control and Prevention) to obtain information on maternal vaccination. RESULTS: Inactivated vaccines are recommended for pregnant women by gynecologic societies in Japan, the United States, and the United Kingdom. Among pregnant Japanese women, the influenza and COVID-19 (two doses) vaccine coverage rates were 27.0%-53.5% (six studies) and 73.6% (one study), respectively; there are no studies on maternal vaccination with DTaP. Concerns regarding vaccine safety are a major barrier to maternal vaccination across countries. Maternal vaccination is effective in preventing severe disease in pregnant women and protecting infants aged <6 months, is generally safe, and does not increase the risk of adverse maternal and fetal outcomes. Providing accurate information regarding vaccination through healthcare providers and the government and government funding for vaccines may help improve maternal vaccination rates in Japan. CONCLUSION: Current coverage for maternal vaccination is still low globally mainly because of vaccine hesitancy among pregnant women. The government, drug-regulatory authorities, and healthcare professionals must educate pregnant women about the effectiveness and safety of maternal vaccines and encourage vaccination when the benefits outweigh the risks.

Protecting pregnant people & infants against influenza: A landscape review of influenza vaccine hesitancy during pregnancy and strategies for vaccine promotion.

Before COVID-19, influenza vaccines were the most widely recommended vaccine during pregnancy worldwide. In response to immunization during pregnancy, maternal antibodies offer protection against potentially life-threatening disease in both pregnant people and their infants up to six months of age. Despite this, influenza vaccine hesitancy is common, with few countries reporting immunization rates in pregnant people above 50%. In this review, we highlight individual, institutional, and social factors associated with influenza vaccine hesitancy during pregnancy. In addition, we present an overview of the evidence evaluating interventions to address influenza vaccine hesitancy during pregnancy. While some studies have indicated promising results, no single intervention has consistently effectively increased influenza vaccine uptake during pregnancy. Using a social-ecological model of health framework, future strategies addressing multiple levels of vaccine hesitancy will be needed to realize the potential health benefits of prenatal immunization programs.

Pregnant people are a high priority group for influenza vaccination annually. Although vaccination can protect both mother and infant, vaccination rates are suboptimal during pregnancy. Previous research has suggested reasons for suboptimal vaccination rates, including concerns about the safety of vaccination during pregnancy and limited access to, and awareness of, influenza vaccines during pregnancy. Studies that have attempted to increase influenza vaccination rates during pregnancy have mostly shown no effect ­ with some exceptions. Public health professionals need to reevaluate strategies for improving vaccination rates during pregnancy.

Comparison of adverse pregnancy and birth outcomes using archival medical records before and during the first wave of the COVID-19 pandemic in Kinshasa, Democratic Republic of Congo: a facility-based, retrospective cohort study.

BACKGROUND: Little research has been conducted on the impact of the coronavirus disease 2019 (COVID-19) pandemic on either birth outcomes or the ability of archival medical records to accurately capture these outcomes. Our study objective is thus to compare the prevalence of preterm birth, stillbirth, low birth weight (LBW), small for gestational age (SGA), congenital microcephaly, and neonatal bloodstream infection (NBSI) before and during the first wave of the COVID-19 pandemic in Kinshasa, Democratic Republic of Congo (DRC). METHODS: We conducted a facility-based retrospective cohort study in which identified cases of birth outcomes were tabulated at initial screening and subcategorized according to level of diagnostic certainty using Global Alignment of Immunization Safety Assessment in pregnancy (GAIA) definitions. Documentation of any birth complications, delivery type, and maternal vaccination history were also evaluated. The prevalence of each birth outcome was compared in the pre-COVID-19 (i.e., July 2019 to February 2020) and intra-COVID-19 (i.e., March to August 2020) periods via two-sample z-test for equality of proportions. RESULTS: In total, 14,300 birth records were abstracted. Adverse birth outcomes were identified among 22.0% and 14.3% of pregnancies in the pre-COVID-19 and intra-COVID-19 periods, respectively. For stillbirth, LBW, SGA, microcephaly, and NBSI, prevalence estimates were similar across study periods. However, the prevalence of preterm birth in the intra-COVID-19 period was significantly lower than that reported during the pre-COVID-19 period (8.6% vs. 11.5%, p < 0.0001). Furthermore, the level of diagnostic certainty declined slightly across all outcomes investigated from the pre-COVID-19 to the intra-COVID-19 period. Nonetheless, diagnostic certainty was especially low for certain outcomes (i.e., stillbirth and NBSI) regardless of period; still, other outcomes, such as preterm birth and LBW, had moderate to high levels of diagnostic certainty. Results were mostly consistent when the analysis was focused on the facilities designated for COVID-19 care. CONCLUSION: This study succeeded in providing prevalence estimates for key adverse birth outcomes using GAIA criteria during the COVID-19 pandemic in Kinshasa, DRC. Furthermore, our study adds crucial real-world data to the literature surrounding the impact of the COVID-19 pandemic on maternal and neonatal services and outcomes in Africa.

Protecting the Offspring, the Gift of Maternal Immunization: Current Status and Future Perspectives.

Pregnancy is characterized by immunological alterations in pregnant women that permit the growth of a semi-allogenic fetus, resulting in greater susceptibility of childbearing women to infections. Furthermore, due to the immaturity of the immune system of neonates, a protection gap is present in early life, leaving neonates and infants vulnerable to infectious diseases with increased morbidity and mortality. Maternal immunization against influenza, pertussis, and, in the context of the COVID-19 pandemic, SARS-CoV-2 has been implemented in several countries, with beneficial effects on both the mother and the offspring. The main protective mechanism of vaccination during pregnancy is transplacental transfer of maternal antibodies. However, recent evidence has implied that the fetal immune system may be influenced beyond passive immunity. This review sheds light on the current status of the routinely administered vaccinations during pregnancy, focusing on the impact of maternal immunization on the priming of the fetal immune system and suggesting future perspectives for the optimization of vaccination strategies.

Evaluation of immunogenicity and reactogenicity of COVID-19 vaccines in pregnant women.

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnancy is associated with increased risk of adverse maternal and perinatal outcomes. Vaccines are highly effective at preventing severe coronavirus disease 2019 (COVID-19), but there are limited data on COVID-19 vaccines in pregnancy. This study aimed to investigate the reactogenicity and immunogenicity of COVID-19 vaccines in pregnant women when administered according to the 12-week-interval dosing schedule recommended in the UK. METHODS: This was a cohort study of pregnant women receiving COVID-19 vaccination between April and September 2021. The outcomes were immunogenicity and reactogenicity after COVID-19 vaccination. Pregnant women were recruited by phone, e-mail and/or text and were vaccinated according to vaccine availability at their local vaccination center. For immunogenicity assessment, blood samples were taken at specific timepoints after each dose to evaluate nucleocapsid protein (N) and spike protein (S) antibody titers. The comparator group comprised non-pregnant female healthcare workers in the same age group who were vaccinated as part of the national immunization program in a contemporaneous longitudinal cohort study. Longitudinal changes in serum antibody titers and association with pregnancy status were assessed using a two-step regression approach. Reactogenicity assessment in pregnant women was undertaken using an online questionnaire. The comparator group comprised non-pregnant women aged 18-49 years who had received two vaccine doses in primary care. The association of pregnancy status with reactogenicity was assessed using logistic regression analysis. RESULTS: Overall, 67 pregnant women, of whom 66 had received a mRNA vaccine, and 79 non-pregnant women, of whom 50 had received a mRNA vaccine, were included in the immunogenicity study. Most (61.2%) pregnant women received their first vaccine dose in the third trimester, while 3.0% received it in the first trimester and 35.8% in the second trimester. SARS-CoV-2 S-antibody geometric mean concentrations after mRNA vaccination were not significantly different at 2-6 weeks after the first dose but were significantly lower at 2-6 weeks after the second dose in infection-naïve pregnant compared with non-pregnant women. In pregnant women, prior infection was associated with higher antibody levels at 2-6 weeks after the second vaccine dose. Reactogenicity analysis included 108 pregnant women and 116 non-pregnant women. After the first dose, tiredness and chills were reported less commonly in pregnant compared with non-pregnant women (P = 0.043 and P = 0.029, respectively). After the second dose, feeling generally unwell was reported less commonly (P = 0.046) in pregnant compared with non-pregnant women. CONCLUSIONS: Using an extended 12-week interval between vaccine doses, antibody responses after two doses of mRNA COVID-19 vaccine were found to be lower in pregnant compared with non-pregnant women. Strong antibody responses were achieved after one dose in previously infected women, regardless of pregnancy status. Pregnant women reported fewer adverse events after both the first and second dose of vaccine. These findings should now be addressed in larger controlled studies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Lack of clear national policy guidance on COVID-19 vaccines influences behaviors in pregnant and lactating women in Kenya.

SARS-CoV-2 infection in pregnancy is associated with a greater risk of maternal and newborn morbidity and maternal death. In Kenya, pregnant and lactating women (PLW) were ineligible to receive COVID-19 vaccines until August 2021. How shifts in policy influence vaccine behaviors, such as health worker recommendations and vaccine uptake, is not well documented. We conducted qualitative interviews with PLW, health workers, and policymakers in Kenya to understand how different stakeholders' perceptions of national policy regarding COVID-19 vaccination in pregnancy shaped vaccine behaviors and decision-making. Policymakers and health workers described pervasive uncertainty and lack of communication about the national policy, cited vaccine safety as their primary concern for administering COVID-19 vaccines to PLW, and expressed that PLW were inadequately prioritized in the COVID-19 vaccine program. PLW perceived the restrictive policy as indicative of a safety risk, resulting in vaccine hesitancy and potentially exacerbated inequities in vaccine access. These findings support the need for the development and dissemination of effective vaccine communication guidelines and the prioritization of PLW in COVID-19 vaccination policies and campaigns. To ensure PLW do not face the same inequities in future epidemics, data on infectious disease burdens and vaccine uptake should be collected systematically among pregnant women, and PLW should be included in future vaccine trials.

A socio-ecological exploration to identify factors influencing the COVID-19 vaccine decision-making process among pregnant and lactating women: Findings from Kenya.

The vaccine decision-making process of pregnant and lactating women is complex. Regarding COVID-19, pregnant women are at increased risk for severe disease and poor health outcomes. While pregnant and lactating women were excluded from COVID-19 vaccine trials, available evidence suggests that COVID-19 vaccines are safe and protective during pregnancy. In this study, we used a socio-ecological approach to explore factors influencing the decision-making process for COVID-19 vaccines in pregnant and lactating women in Kenya, for the purpose of informing demand generation strategies. As pregnant and lactating women are influenced by many factors, we conducted 84 in-depth interviews with a variety of stakeholders, including 31 pregnant or lactating women, 20 healthcare workers such as nurses, midwives, doctors, and frontline workers, 25 male family members of pregnant or lactating women, and 8 gatekeepers such as community leaders and faith-based leaders. These individuals were recruited from six communities in Kenya: three urban, and three rural. We applied a grounded theory approach to identify emerging themes and organized emerging themes using the SAGE Vaccine Hesitancy model, which includes three categories of determinants of vaccine acceptance, including contextual influences, individual and group influences, and vaccine and vaccination specific issues. Myths, interpersonal norms, and religion emerged as themes related to contextual influences. Safety, risk perception, and the role of the healthcare worker emerged as themes related to individual and group influences. For vaccine and vaccination specific issues, emerging themes included availability, accessibility, and eligibility. While maternal immunization can substantially reduce the effect of infectious diseases in mothers and infants, vaccine acceptance is critical. However, vaccines do not save lives; vaccination does. We hope the results of this study can be used to tailor communication efforts to increase vaccine demand among pregnant and lactating women.

Association between social vulnerability and COVID-19 vaccination hesitancy and vaccination in pregnant and postpartum individuals.

OBJECTIVE: To evaluate the association of community-level social vulnerability with COVID-19 vaccine hesitancy and vaccination among pregnant and postpartum individuals. METHODS: Prospective cohort study assessing COVID-19 vaccine hesitancy among pregnant and postpartum individuals. We performed a baseline survey on COVID-19 vaccine hesitancy from 03/22/21 to 04/02/21, and a follow-up survey on COVD-19 vaccination status 3- to 6-months later. The primary exposure was the Centers for Disease Control and Prevention SVI (Social Vulnerability Index), measured in quartiles. Higher SVI quartiles indicated greater community-level social vulnerability with the lowest quartile (quartile 1) as the referent group. The primary outcome was COVID-19 vaccine hesitancy on the baseline survey (uncertainty or refusal of the vaccine), and the secondary outcome was self-report of not being vaccinated (unvaccinated) for COVID-19 on the follow-up survey. RESULTS: Of 456 assessed individuals, 46% reported COVID-19 vaccine hesitancy on the baseline survey; and of 290 individuals (290/456, 64%) who completed the follow-up survey, 48% (140/290) were unvaccinated. The frequency of baseline vaccine hesitancy ranged from 25% in quartile 1 (low SVI) to 68% in quartile 4 (high SVI), and being unvaccinated at follow-up ranged from 29% in quartile 1 to 77% in quartile 4. As social vulnerability increased, the risk of COVID-19 vaccine hesitancy at baseline increased (quartile 2 aRR (adjusted relative risk): 1.46; 95% CI:0.98 to 2.19; quartile 3 aRR: 1.86; 95% CI:1.28 to 2.71; and quartile 4 aRR: 2.24; 95% CI:1.56 to 3.21), as did the risk of being unvaccinated at follow-up (quartile 2 aRR: 1.00; 95% CI:0.66 to 1.51; quartile 3 aRR: 1.68; 95% CI:1.17 to 2.41; and quartile 4 aRR: 1.82; 95% CI:1.30 to 2.56). CONCLUSIONS: Pregnant and postpartum individuals living in an area with higher community-level social vulnerability were more likely to report COVID-19 vaccine hesitancy and subsequently to be unvaccinated at follow-up.

Maternal vaccination as an additional approach to improve the protection of the nursling: Anti-infective properties of breast milk.

Human milk constitutes a secretion with unique functions of both nourishing the nursling and providing protection against enteric and respiratory infections, mainly due to its content of secretory IgA antibodies but also due to the presence of a plethora of bioactive factors. Specific IgA antibodies are produced locally by plasma cells derived from B lymphocytes that migrate from other mucosae to the mammary gland during lactation, particularly from the gastrointestinal and respiratory tracts. Therefore, here, the authors will provide a comprehensive review of the content and functions of different nutritional and bioactive anti-infectious components from breast milk, such as oligosaccharides, lactoferrin, haptocorrin, α-lactalbumin, k-casein, lysozyme, lactoperoxidase, mucin, fatty acids, defensins, cytokines and chemokines, hormones and growth factors, complement proteins, leukocytes and nucleic acids, including microRNAs, among many others, and the induction of antibody responses in breast milk after maternal vaccination with several licensed vaccines, including the anti-SARS-CoV-2 vaccine preparations used worldwide. Currently, in the midst of the pandemic, maternal vaccination has re-emerged as a crucial source of passive immunity to the neonate through the placenta and breastfeeding, considering that maternal vaccination can induce specific antibodies if performed during pregnancy and after delivery. There have been some reports in the literature about milk IgA antibodies induced by bacterial antigens or inactivated virus vaccines, such as anti-diphtheria-tetanus-pertussis, anti-influenza viruses, anti-pneumococcal and meningococcal polysaccharide preparations. Regarding anti-SARS-CoV-2 vaccines, most studies demonstrate elevated levels of specific IgA and IgG antibodies in milk with virus-neutralizing ability after maternal vaccination, which represents an additional approach to improve the protection of the nursling during the entire breastfeeding period.

Biological factors that may impair transplacental transfer of RSV antibodies: Implications for maternal immunization policy and research priorities for low- and middle-income countries.

Respiratory syncytial virus (RSV) is the leading viral cause of acute lower respiratory tract infection (ALRI), including bronchiolitis and pneumonia, in infants and children worldwide. Protection against RSV is primarily antibody mediated and passively acquired RSV neutralizing antibody can protect infants from RSV ALRI. Maternal immunization is an attractive strategy for the prevention of RSV in early infancy when immune responses to active immunization may be suboptimal and most severe RSV disease and death occur. However, several biologic factors have been shown to potentially attenuate or interfere with the transfer of protective naturally acquired antibodies from mother to fetus and could therefore also reduce vaccine effectiveness through impairment of transfer of vaccine-induced antibodies. Many of these factors are prevalent in low- and middle-income countries (LMIC) which experience the greatest burden of RSV-associated mortality; more data are needed to understand these mechanisms in the context of RSV maternal immunization. This review will focus on what is currently known about biologic conditions that may impair RSV antibody transfer, including preterm delivery, low birthweight, maternal HIV infection, placental malaria, and hypergammaglobulinemia (high levels of maternal total IgG). Key data gaps and priority areas for research are highlighted and include improved understanding of the epidemiology of hypergammaglobulinemia and the mechanisms by which it may impair antibody transfer. Key considerations for ensuring optimal vaccine effectiveness in LMICs are also discussed.

Risk Measurement of Perinatal and Neonatal Morbidity Characteristics and Applicability of GAIA Case Definitions: Results and Lessons Learnt of a Hospital-Based Prospective Cohort Study in the Valencia Region (2019-2020).

Post-marketing safety surveillance of new vaccines aimed to be administered during pregnancy is crucial to orchestrate efficient adverse events evaluation. This is of special relevance in the current landscape of new vaccines being introduced in the pregnant women population, and particularly due to the recent administration of COVID-19 vaccines in pregnant women. This multi-center prospective cohort study, nested within the WHO-Global Vaccine Safety-MCC study, involved two hospitals in the Valencia region. Hereby, the incidence rates of seven perinatal and neonatal outcomes in the Valencia region are presented. The pooled data analysis of the two Valencian hospitals allowed the estimation of incidence rates in the Valencia Region (per 1000 live births): 86.7 for low birth weight, 78.2 for preterm birth, 58.8 for small for gestational age, 13 for congenital microcephaly, 0.4 for stillbirth, 1.2 for neonatal death and 6.5 for neonatal infection. These figures are in line with what is expected from a high-income country and the previously reported rates for Spain and Europe, except for the significantly increased rate for congenital microcephaly. Regarding the data for maternal immunization, the vaccination status was collected for 94.4% of the screened pregnant women, highlighting the high quality of the Valencian Vaccine Registry. The study also assessed the Valencian hospitals' capacity for identifying and collecting data on maternal immunization status, as well as the applicability of the GAIA definitions to the identified outcomes.

Effect of pertussis vaccine in pregnancy and COVID-19 pandemic in the cases of wooping cough.

BACKGROUND: Whooping cough has had an increased incidence and severity specially in infants and maternal immunization has been implemented as a prevention strategy. COVID-19 pandemic seems to decrease the incidence of other respiratory diseases. METHODS: Retrospective study from 2012 to 2021 to assess the influence of pertussis maternal immunizations and the first year of COVID-19 pandemic in the cases of whooping cough. RESULTS: 960 suspected cases from primary care and hospital, with 130 cases (104 children and 26 adults) being diagnosed of whooping cough. In the post-vaccination period, a reduction in the cases and severity in infants up to 6 months old was observed as well as in the pertussis diagnosis in adult women. There were no whooping cough cases during the COVID-19 period. CONCLUSIONS: Both the pertussis vaccination in pregnancy and the first year of the COVID-19 pandemic have decreased the number of pertussis cases.

Regulatory considerations for study of infant protection through maternal immunization.

Childhood Immunization is one of the critical strategies to decrease infant morbidity and mortality due to infectious diseases, but primary immunization schedules for infants in most countries start at 2 months of age. Childhood vaccines therefore begin providing adequate protection later in life, leaving infants vulnerable to infectious diseases and creating an immunity gap that results in higher morbidity and mortality among younger infants. Maternal immunization, the practice of vaccinating individuals during pregnancy, reduces the risk of infant infection primarily through the transfer of protective maternal antibodies to the fetus during late pregnancy. Although much progress has been made in public health policies to support maternal immunization research, inclusion of pregnant individuals and children in clinical trials remains challenging. This has resulted in paucity of evidence regarding safety and effectiveness of vaccines to support licensure of products intended for use during pregnancy and lactation to prevent disease in the infant. In addition, although safeguards for clinical research in pregnancy are supportive, experimental vaccines, e.g., Respiratory Syncytial Virus, are more complicated to study because data on safety, efficacy, and dosing are limited. This requires randomized controlled trials with safety monitoring for the mother, the fetus, and the infant with follow-up for at least 1 year or longer to assess long-term health outcomes that may be associated with peripartum vaccine exposure. The goal of this paper is to discuss the general regulatory considerations for clinical research to evaluate safety and effectiveness of vaccines administered during pregnancy to protect infants from disease. This could be useful to inform future vaccine trials. This discussion is not intended to provide agency guidance nor to articulate agency policy.

Association of initial COVID-19 vaccine hesitancy with subsequent vaccination among pregnant and postpartum individuals.

OBJECTIVE: To examine the association between initial COVID-19 vaccine hesitancy and subsequent vaccination among pregnant and postpartum individuals. DESIGN: Prospective cohort. SETTING: A Midwestern tertiary-care academic medical center. Individuals completed a baseline vaccine hesitancy assessment from 22 March 2021 to 2 April 2021, with subsequent ascertainment of vaccination status at 3-6 months follow-up. METHODS: We used multivariable Poisson regression to estimate the relative risk of vaccination by baseline vaccine hesitancy status, and then characteristics associated with vaccination. MAIN OUTCOME MEASURES: Self-report of COVID-19 vaccination, and secondarily, consideration of COVID-19 vaccination among those not vaccinated. RESULTS: Of 456 individuals (93% pregnant, 7% postpartum) initially surveyed, 290 individuals (64%; 23% pregnant, 77% postpartum) provided subsequent vaccination status (median = 17 weeks). Of these 290 individuals, 40% (116/290) reported COVID-19 vaccine hesitancy upon enrolment, of whom 52% reported subsequent vaccination at follow-up. Few individuals transitioned during the study period from vaccine hesitant to vaccinated (10%); in comparison, 80% of those who were not vaccine hesitant were vaccinated at follow-up (aRR 0.19, 95% CI 0.11-0.33). Among those who remained unvaccinated at follow-up, 38% who were vaccine hesitant at baseline were considering vaccination, compared with 71% who were not vaccine hesitant (aRR 0.48, 95% CI 0.33-0.67). Individuals who were older, parous, employed and of higher educational attainment were more likely to be vaccinated, and those who identified as non-Hispanic black, were Medicaid beneficiaries, and were still pregnant at follow-up were less likely to be vaccinated. CONCLUSIONS: COVID-19 vaccine hesitancy persisted over time in the peripartum period, and few individuals who reported hesitancy at baseline were later vaccinated. Interventions that address vaccine hesitancy in pregnancy are needed.