The Interplay of Perceived Risks and Benefits in Deciding to Become Vaccinated against COVID-19 While Pregnant or Breastfeeding: A Cross-Sectional Study in Italy.

The present study examined the role of the perception of risks and benefits for the mother and her babies in deciding about the COVID-19 vaccination. In this cross-sectional study, five hypotheses were tested using data from a convenience sample of Italian pregnant and/or breastfeeding women (N = 1104, July-September 2021). A logistic regression model estimated the influence of the predictors on the reported behavior, and a beta regression model was used to evaluate which factors influenced the willingness to become vaccinated among unvaccinated women. The COVID-19 vaccination overall risks/benefits tradeoff was highly predictive of both behavior and intention. Ceteris paribus, an increase in the perception of risks for the baby weighed more against vaccination than a similar increase in the perception of risks for the mother. Additionally, pregnant women resulted in being less likely (or willing) to be vaccinated in their status than breastfeeding women, but they were equally accepting of vaccination if they were not pregnant. COVID-19 risk perception predicted intention to become vaccinated, but not behavior. In conclusion, the overall risks/benefits tradeoff is key in predicting vaccination behavior and intention, but the concerns for the baby weigh more than those for the mother in the decision, shedding light on this previously neglected aspect.

Safety and Effectiveness of Maternal COVID-19 Vaccines Among Pregnant People and Infants.

Evidence has consistently demonstrated that COVID-19 messenger RNA (mRNA) vaccines are safe when given during pregnancy. COVID-19 mRNA vaccines protect pregnant people and their infants who are too young to receive COVID-19 vaccines. Although generally protective, monovalent vaccine effectiveness was lower during SARS-CoV-2 Omicron variant predominance, in part due to changes in the Omicron spike protein. Bivalent vaccines, that combine ancestral strain and Omicron variant, may improve protection against Omicron variants. Everyone, including pregnant people, should stay up to date with recommended COVID-19 vaccines and bivalent booster, when eligible.

Recent progress in immunoprophylaxis of severe acute respiratory syndrome coronavirus 2 in children younger than 5 years.

Immunoprophylaxis refers to the strategy to enhance specific immunity of the body through artificial methods, which can be divided into active immunization (mainly vaccination) and passive immunization (including maternal vaccination). Vaccination is the most cost - effective measure to prevent and control the novel coronavirus disease 2019 (COVID -19). Recently, the United States, Costa Rica and Australia have authorized use of the COVID - 19 vaccine for children down to 6 months of age. In real - world evaluation, maternal vaccination was associated with a substantial reduction in incidence of severe acute respiratory syndrome coronavirus 2 (SARS - CoV - 2) infection, the risk of COVID - 19 related hospitalization and critical illness among infants younger than 6 months of age. Coupled with these advances in young children, it is possible to achieve the whole population coverage of SARS - CoV - 2 mmune prevention.Copyright © 2022 Chinese Journal of Applied Clinical Pediatrics. All rights reserved.

SARS-CoV-2 placentitis, stillbirth, and maternal COVID-19 vaccination: clinical-pathologic correlations.

Stillbirth is a recognized complication of COVID-19 in pregnant women that has recently been demonstrated to be caused by SARS-CoV-2 infection of the placenta. Multiple global studies have found that the placental pathology present in cases of stillbirth consists of a combination of concurrent destructive findings that include increased fibrin deposition that typically reaches the level of massive perivillous fibrin deposition, chronic histiocytic intervillositis, and trophoblast necrosis. These 3 pathologic lesions, collectively termed SARS-CoV-2 placentitis, can cause severe and diffuse placental parenchymal destruction that can affect >75% of the placenta, effectively rendering it incapable of performing its function of oxygenating the fetus and leading to stillbirth and neonatal death via malperfusion and placental insufficiency. Placental infection and destruction can occur in the absence of demonstrable fetal infection. Development of SARS-CoV-2 placentitis is a complex process that may have both an infectious and immunologic basis. An important observation is that in all reported cases of SARS-CoV-2 placentitis causing stillbirth and neonatal death, the mothers were unvaccinated. SARS-CoV-2 placentitis is likely the result of an episode of SARS-CoV-2 viremia at some time during the pregnancy. This article discusses clinical and pathologic aspects of the relationship between maternal COVID-19 vaccination, SARS-CoV-2 placentitis, and perinatal death.

Effectiveness of BNT162b2 Vaccination During Pregnancy in Preventing Hospitalization for Severe Acute Respiratory Syndrome Coronavirus 2 in Infants.

OBJECTIVE: To assess the clinical effectiveness of the BNT162b2 vaccine during pregnancy in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hospitalizations of infants. STUDY DESIGN: A retrospective, multicenter, 1:3 case-control (test-negative) study. Symptomatic hospitalized infants less than 6 months of age, with a positive SARS-CoV-2 polymerase chain reaction test between January 3, 2021, and March 11, 2021, were matched by age and time to negative controls, hospitalized with symptoms compatible with SARS-CoV-2 infection. Mothers were defined as fully vaccinated who received 2 doses of BNT162b2 with the second given 2 weeks to 6 months before delivery; or partially vaccinated, if they received only 1 dose or 2 doses with the second given more than 6 months or less than 2 weeks before delivery. Severe SARS-CoV-2 was defined as a need for assisted ventilation. RESULTS: We matched 116 SARS-CoV-2 positive infants with 348 negative controls with symptoms compatible with SARS-CoV-2 infection. The effectiveness of fully vaccinated mothers was 61.6% (95% CI, 31.9-78.4) and the effectiveness of partially vaccinated mothers was not significant. Effectiveness was higher in infants 0-2 vs 3-6 months of age. The effectiveness (57.1%; 95% CI, 22.8-76.4) was similar when excluding mothers who were infected with SARS-CoV-2 during pregnancy. The OR of severe infection in infants born to unvaccinated vs fully vaccinated mothers was 5.8. CONCLUSIONS: At least 2 doses of BNT162b2 vaccine administered during the second or third trimester of pregnancy had an effectiveness of 61.6% in decreasing hospitalization for SARS-CoV-2 infection in infants less than 6 months of age.

Recent progress in immunoprophylaxis of severe acute respiratory syndrome coronavirus 2 in children younger than 5 years

Immunoprophylaxis refers to the strategy to enhance specific immunity of the body through artificial methods, which can be divided into active immunization (mainly vaccination) and passive immunization (including maternal vaccination). Vaccination is the most cost - effective measure to prevent and control the novel coronavirus disease 2019 (COVID -19). Recently, the United States, Costa Rica and Australia have authorized use of the COVID - 19 vaccine for children down to 6 months of age. In real - world evaluation, maternal vaccination was associated with a substantial reduction in incidence of severe acute respiratory syndrome coronavirus 2 (SARS - CoV - 2) infection, the risk of COVID - 19 related hospitalization and critical illness among infants younger than 6 months of age. Coupled with these advances in young children, it is possible to achieve the whole population coverage of SARS - CoV - 2 mmune prevention. © 2022 Chinese Journal of Applied Clinical Pediatrics. All rights reserved.

Knowledge and decisions about maternal immunisation by pregnant women in Aotearoa New Zealand.

BACKGROUND: Maternal vaccinations for influenza and pertussis are recommended in New Zealand to protect mothers and their infant from infection. However, maternal immunisation coverage in New Zealand is suboptimal. Furthermore, there is unacceptable inequitable maternal immunisation rates across the country with Maori and Pacific women having significantly lower maternal immunisation rates than those of other New Zealanders. METHODS: This research set out to explore what pregnant/recently pregnant Maori and Pacific women knew about immunisation during pregnancy and what factors influenced their decision to be vaccinated. A semi-structured interview guide was developed with questions focusing on knowledge of pertussis and influenza vaccination during pregnancy and decision-making. Maori and Pacific women aged over 16 years were purposively sampled and interviewed in Dunedin and Gisborne, New Zealand between May and August 2021. Interviews were analysed following a directed qualitative content approach. Data were arranged into coding nodes based on the study aims (deductive analysis) informed by previous literature and within these participant experiences were inductively coded into themes and subthemes. RESULTS: Not all women were aware of maternal vaccine recommendations or they diseases they protected against. Many underestimated how dangerous influenza and pertussis could be and some were more concerned about potential harms of the vaccine. Furthermore, understanding potential harms of infection and protection provided by vaccination did not necessarily mean women would choose to be vaccinated. Those who decided to vaccinate felt well-informed, had vaccination recommended by their healthcare provider, and did so to protect their and their infant's health. Those who decided against vaccination were concerned about safety of the vaccines, lacked the information they needed, were not offered the vaccine, or did not consider vaccination a priority. CONCLUSIONS: There is a lack of understanding about vaccine benefits and risks of vaccine-preventable diseases which can result in the reinforcement of negative influences such as the fear of side effects. Furthermore, if vaccine benefits are not understood, inaccessibility of vaccines and the precedence of other life priorities may prevent uptake. Being well-informed and supported to make positive decisions to vaccinate in pregnancy is likely to improve vaccine coverage in Maori and Pacific Island New Zealanders.

Lessons from a mature acellular pertussis vaccination program and strategies to overcome suboptimal vaccine effectiveness.

INTRODUCTION: Despite high vaccination coverage among children and adolescents, pertussis remains a public health problem, with large outbreaks occurring periodically in the US and other developed countries. AREAS COVERED: We examine lessons learned more than 20 years after implementation of programs which use only acellular pertussis vaccines and propose avenues for possible effective use of acellular pertussis vaccine to prevent large outbreaks. EXPERT OPINION: Acellular pertussis vaccines were introduced more than 20 years ago, yet the incidence of pertussis has been increasing over the past decade, with periodic large outbreaks marked by notable shifts in disease burden from infants and young children toward fully vaccinated adolescents and young adults. This age shift is mainly driven by the waning of vaccine immunity. To better protect adolescents against pertussis, modification of the current acellular pertussis vaccination schedule or adoption of new vaccination strategies should be considered. For infants not yet eligible to be vaccinated, maternal vaccination against pertussis during pregnancy is an effective way to protect infants from infection, severe disease and death. Implementation of maternal vaccination programs should be encouraged in countries without one or efforts to improve coverage should be supported in countries with existing program.

Coronavirus Disease 2019 Infection in Newborns.

Maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can present with or without symptoms at the time of birth. Symptomatic mothers are more likely be associated with preterm births. Population studies demonstrate a consistent association of SARS-CoV-2 infection and a reduction in preterm birth rate. Newborns with positive SARS-CoV-2 test results appear to have minimal burden of illness that is directly associated with a viral infection. Neonatal mortality directly related to SARS-CoV-2 is extremely rare. Maternal vaccination in pregnant women leads to maternal antibody production, and this can occur as early as 5 days after the first vaccination dose.

COVID-19 vaccine acceptance and coverage among pregnant persons in the United States.

Pregnant persons are at higher risk of severe COVID-19. Although vaccination is recommended, COVID-19 vaccination rates are lower among pregnant persons compared to the non-pregnant population. We aimed to evaluate acceptance of any dose of COVID-19 vaccine during pregnancy. A national online cross-sectional survey of US adults who were pregnant between December 2020 and July 2021 was used to measure COVID-19 vaccine behaviors, attitudes, and beliefs. Post-stratification weighting was used to ensure representativeness to the US population. Marginal log-binomial models were used to estimate adjusted prevalence ratios (aPR) of COVID-19 vaccine acceptance, accounting for sociodemographic factors. Of 5,660 who responded to survey advertisements, 2,213 met eligibility criteria and completed the survey; 55.4% of respondents received or planned to receive COVID-19 vaccine prior to or during pregnancy, 27.0% planned to vaccinate after pregnancy, 8.8% were unsure and 8.7% had no plans to vaccinate. Individuals were more likely to receive or plan to receive COVID-19 vaccine if they had group prenatal care (aPR 1.57; 95% CI 1.40, 1.75), were employed in a workplace with a policy recommending vaccination (aPR 1.15; 95% CI 1.06, 1.26), and believed COVID-19 vaccines are safe (aPR 2.86; 95% CI 2.49, 3.29). Pregnant persons who were recommended COVID-19 vaccination by their healthcare provider less commonly reported concerns about vaccine safety (35.5% vs 55.9%) and were more likely to accept COVID-19 vaccines (aPR 1.52; 95% CI 1.31, 1.76). COVID-19 vaccine acceptance during pregnancy is not universal and public health intervention will be needed to continue to increase vaccine coverage.

Vaccinations in pregnancy.

Vaccinations are a cost-effective means of preventing disease. They may be recommended primarily for maternal benefit or for prevention of intrauterine fetal or early neonatal infection. Data from the International Network of Obstetric Survey Systems relating to the COVID-19 pandemic showed that for all countries studied (the UK, the Netherlands, Norway, Denmark, Finland and Italy), at least 80% of pregnant women admitted to critical care were unvaccinated. In the UK this figure was 98%. The MBRRACE-UK 2014 report, covering 2009-2012 during the H1N1 epidemic, demonstrated that one in eleven maternal mortalities were directly from influenza virus: more than half could have been prevented by the flu vaccine in pregnancy. Research is ongoing to develop additional vaccines for infections that cause detrimental effects to pregnant women and their infants. Theoretical concerns regarding adverse effects to the fetus and lack of efficacy have, in general, not been confirmed by clinical evidence. Nevertheless, live attenuated vaccines remain contraindicated due to risk of fetal infection. As with any clinical decision, advice on antenatal vaccination should be based on the balance of risks and benefits to mother and fetus. This article aims to guide such decisions by discussing the issues surrounding commonly used vaccines and presenting current UK guidelines.

Assessing the feasibility of passive surveillance for maternal immunization safety utilizing archival medical records in Kinshasa, Democratic Republic of the Congo.

INTRODUCTION: Since the establishment of the Global Alignment of Immunization Safety Assessment in pregnancy (GAIA) case definitions in 2015, there has been an urgent need for field validation of pharmacovigilance feasibility in low- and middle-income countries. In this study, we assess the availability and quality of archival medical records at ten randomly selected high-traffic maternity wards in Kinshasa province, Democratic Republic of Congo (DRC). METHODS: A retrospective cohort of mother-child pairs was established from all recorded births taking place at study sites between July 1, 2019 to February 28, 2020 through digitization of medical records. Adverse birth outcomes and maternal vaccination status, where available and linkable, were defined according to GAIA. Basic demographic information on mothers and newborns was also tabulated; birth outcomes were assessed for both intra-site prevalence and a pooled prevalence. RESULTS: A total of 7,697 mother-newborn pair records were extracted, with 37% of infants screening positive as cases of adverse outcomes. Maternal vaccination information was linkable to 67% of those cases. In total, 51% of stillbirths, 98% of preterm births, 100% of low birthweight infants, 90% of small for gestational age infants, 100% of microcephalic infants, and 0% of neonatal bloodstream infections were classifiable according to GAIA standards following initial screening. Forty percent of case mothers had some indication of tetanus vaccination prior to delivery in their medical records, but only 26% of case mothers met some level of GAIA definition for maternal vaccination during the pregnancy of interest. CONCLUSIONS: Archival birth records from delivery centers can be feasibly utilized to screen for stillbirth and maternal tetanus vaccination, and to accurately classify preterm birth, low birthweight, small for gestational age, and congenital microcephaly. Assessment of other neonatal outcomes were limited by inconsistent postpartum infant follow-up and records keeping.

Maternal vaccination: a review of current evidence and recommendations.

Maternal vaccination is an effective means of protecting pregnant women, their fetuses, and infants from vaccine-preventable infections. Despite the availability of sufficient safety data to support the use of vaccines during pregnancy, maternal immunization remains an underutilized method of disease prevention, often because of concerns from both healthcare providers and pregnant women about vaccine safety. Such concerns have been reflected in the low uptake of the COVID-19 vaccine among pregnant women seen in many parts of the world. Here, we present an update of the current recommendations for the use of vaccines during pregnancy, including the evidence supporting the use of novel vaccine platforms. We also provide an overview of the data supporting the use of COVID-19 vaccines in pregnancy and an update of the status of vaccines that are currently under development for use in pregnant women.

Global Perspectives on Immunization Against SARS-CoV-2 During Pregnancy and Priorities for Future Research: An International Consensus Paper From the World Association of Infectious Diseases and Immunological Disorders.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnancy is associated with a higher risk for severe morbidity and mortality when compared with infection in non-pregnant women of childbearing age. An increasing number of countries recommend immunization against SARS-CoV-2 in pregnant women. Recent studies provide preliminary and supportive evidence on safety, immunogenicity and effectiveness of coronavirus disease 2019 (COVID-19) vaccines in pregnant women; however, important knowledge gaps remain which warrant further studies. This collaborative consensus paper provides a review of the current literature on COVID-19 vaccines in pregnant women, identifies knowledge gaps and outlines priorities for future research to optimize protection against SARS-CoV-2 in the pregnant women and their infants.

Secretory IgA and T cells targeting SARS-CoV-2 spike protein are transferred to the breastmilk upon mRNA vaccination.

In view of the scarcity of data to guide decision making, we evaluated how BNT162b2 and mRNA-1273 vaccines affect the immune response in lactating women and the protective profile of breastmilk. Compared with controls, lactating women had a higher frequency of circulating RBD memory B cells and higher anti-RBD antibody titers but similar neutralizing capacity. We show that upon vaccination, immune transfer to breastmilk occurs through a combination of anti-spike secretory IgA (SIgA) antibodies and spike-reactive T cells. Although we found that the concentration of anti-spike IgA in breastmilk might not be sufficient to directly neutralize SARS-CoV-2, our data suggest that cumulative transfer of IgA might provide the infant with effective neutralization capacity. Our findings put forward the possibility that breastmilk might convey both immediate (through anti-spike SIgA) and long-lived (via spike-reactive T cells) immune protection to the infant. Further studies are needed to address this possibility and to determine the functional profile of spike T cells.

'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.

Evaluating the impact of a continued maternal pertussis immunisation programme in England: A modelling study and cost-effectiveness analysis.

INTRODUCTION: An unexpected resurgence of pertussis cases and infant deaths was observed in some countries that had switched to acellular pertussis vaccines in the primary immunisation schedule. In response to the outbreaks, maternal pertussis vaccination programmes in pregnant women have been adopted worldwide, including the USA in 2011 and the UK in 2012. Following the success of the programme in England, we evaluated the health and economic impact of stopping versus continuing the maternal pertussis immunisation to inform public health policy making. METHODS: We used a mathematical model to estimate the number of infant hospitalisations and deaths related to pertussis in England over 2019-2038. Losses in quality-adjusted life years, QALYs, were considered for infants (aged 0-2 months) who survived or died from pertussis, bereaved parents (of infants who died from pertussis), and women with pertussis (aged 20-44 years). Direct medical costs to the National Health Service included infant hospitalisations, maternal vaccinations, and disease in women. Costs and QALYs were discounted at 3.5%. Changes in the incremental cost-effectiveness ratio, ICER, were explored in sensitivity analyses. RESULTS: The model supports continuing the maternal pertussis immunisation programme as a cost-effective intervention at an ICER of £14,500/QALY (2.5% and 97.5%-quantile: £7,300/QALY to £32,400/QALY). Stopping versus continuing the maternal programme results in an estimated mean of 972 (range 582 to 1489) versus 308 (184 to 471) infant hospitalisations annually. Results were most sensitive to the number of hospitalisations and deaths when stopping the maternal programme. At a cost-effectiveness threshold of £30,000/QALY, the probability of the maternal programme being cost-effective was 96.2%. CONCLUSION: Our findings support continuing the maternal pertussis vaccination programme as otherwise higher levels of disease activity and infant mortality are expected to return. These results have led policy makers to decide to continue the maternal programme in the UK routine immunisation schedule.