Transplacental Transfer Of Maternal Antibodies Research Articles

Passive Immunization Strategies to Prevent Severe Respiratory Syncytial Virus Infection Among Newborns and Young Infants.

Newborns and young infants are at risk for severe respiratory syncytial virus (RSV) lower respiratory tract infection. Passive immunity is the mainstay of infection prevention in this cohort. Transplacental transfer of maternal antibodies provides the newborn with immediate protection from life-threatening infections, however, is dependent upon gestational age, birth weight, mother's age, recent maternal vaccination, maternal nutritional status, maternal immunocompetence and medical conditions, and placental integrity. Efficient transplacental transfer of RSV-neutralizing antibodies have led to the development and approval of maternal RSV immunization for the protection of the newborn. Additionally, administration of RSV-specific antibodies to infants leads to high serum titers of RSV-neutralizing antibodies and further protection from severe disease.

Transplacental transfer of maternal antibodies following immunization with recombinant pertussis vaccines during pregnancy: Real-world evidence

Aim/objectiveThis study investigates placental antibody transfer following recombinant pertussis vaccination in pregnancy in a real-world setting. MethodsThis postmarketing observational study recruited pregnant women vaccinated with monovalent recombinant acellular pertussis (aP) vaccine (aPgen; n = 199) or combined to tetanus-diphtheria (TdaPgen; n = 200), or Td-vaccine only (n = 54). Pregnancy, delivery, and neonatal outcomes were assessed. Cord blood was collected postdelivery and pertussis toxin (PT)-IgG, filamentous hemagglutinin (FHA)-IgG, and PT-neutralizing antibodies (PT-Nab) were assessed. ResultsNo adverse pregnancy, delivery, or neonatal outcomes attributed to aPgen, TdaPgen, or Td vaccination were reported. High anti-PT antibody levels were detected in cord samples from women vaccinated with aPgen (geometric mean concentration [GMC] PT-IgG 206.1 IU/ml, 95% confidence intervals [CI]: 164.3-258.6; geometric mean titer [GMT] PT-Nab 105.3 IU/ml, 95% CI: 81.7-135.8) or TdaPgen (GMC PT-IgG 153.1 IU/ml, 95% CI: 129.1-181.5; GMT PT-Nab 81.5 IU/ml, 95% CI: 66.4-100.0). In the Td-only group, anti-PT antibodies were low (GMC PT-IgG 6.5 IU/ml, 95% CI: 4.9-8.8; GMT PT-Nab 3.8 IU/ml, 95% CI: 2.8-5.1). The same was found for FHA-IgG. Recombinant pertussis vaccination at <27 or 27-36 weeks gestation induced similar cord pertussis antibody levels. ConclusionThis first real-world study confirms that recombinant pertussis vaccination in the second or third trimester of pregnancy results in high levels of passive immunity in infants.Thai Clinical Trial Registry: TCTR20200528006.

Alloimmune hemolytic disease of the fetus and newborn: genetics, structure, and function of the commonly involved erythrocyte antigens.

Hemolytic disease of the fetus and newborn (HDFN) can occur when a pregnant woman has antibody directed against an erythrocyte surface antigen expressed by her fetus. This alloimmune disorder is restricted to situations where transplacental transfer of maternal antibody to the fetus occurs, and binds to fetal erythrocytes, and significantly shortens the red cell lifespan. The pathogenesis of HDFN involves maternal sensitization to erythrocyte "non-self" antigens (those she does not express). Exposure of a woman to a non-self-erythrocyte antigen principally occurs through either a blood transfusion or a pregnancy where paternally derived erythrocyte antigens, expressed by her fetus, enter her circulation, and are immunologically recognized as foreign. This review focuses on the genetics, structure, and function of the erythrocyte antigens that are most frequently involved in the pathogenesis of alloimmune HDFN. By providing this information we aim to convey useful insights to clinicians caring for patients with this condition.

Evidence for the Role of a Second Fc-Binding Receptor in Placental IgG Transfer in Nonhuman Primates.

Transplacental transfer of maternal antibodies provides the fetus and newborn with passive protection against infectious diseases. While the role of the highly conserved neonatal Fc receptor (FcRn) in transfer of IgG in mammals is undisputed, recent reports have suggested that a second receptor may contribute to transport in humans. We report poor transfer efficiency of plant-expressed recombinant HIV-specific antibodies, including engineered variants with high FcRn affinity, following subcutaneous infusion into rhesus macaques close to parturition. Unexpectedly, unlike those derived from mammalian tissue culture, plant-derived antibodies were essentially unable to cross macaque placentas. This defect was associated with poor Fcγ receptor binding and altered Fc glycans and was not recapitulated in mice. These results suggest that maternal-fetal transfer of IgG across the three-layer primate placenta may require a second receptor and suggest a means of providing maternal antibody treatments during pregnancy while avoiding fetal harm. IMPORTANCE This study compared the ability of several human HIV envelope-directed monoclonal antibodies produced in plants with the same antibodies produced in mammalian cells for their ability to cross monkey and mouse placentas. We found that the two types of antibodies have comparable transfer efficiencies in mice, but they are differentially transferred across macaque placentas, consistent with a two-receptor IgG transport model in primates. Importantly, plant-produced monoclonal antibodies have excellent binding characteristics for human FcRn receptors, permitting desirable pharmacokinetics in humans. The lack of efficient transfer across the primate placenta suggests that therapeutic plant-based antibody treatments against autoimmune diseases and cancer could be provided to the mother while avoiding transfer and preventing harm to the fetus.

Maternal hypothyroidism to congenital hypothyroidism in neonates and neonatal outcomes

Introduction: Hypothyroidism is widely prevalent in pregnant women and the rate of detection, especially on a developing country like India, has not kept pace with the magnitude of the problem (1).Since hypothyroidism is easily treated, timely detection and treatment of the disorder could reduce the burden of adverse fetal and maternal outcomes, which are very commonly encountered (1).Congenital hypothyroidism can be caused due to thyroid dysgenesis, disorders of thyroid hormone synthesis, iodine deficiency or excess as well as trans-placental transfer of maternal antibodies or medications. (1). Congenital hypothyroidism is a preventable cause of intellectual disability. Hence it is important to monitor neonates born to mothers with hypothyroidismHypothyroidism is widely prevalent in pregnant women and the rate of detection, especially in a developing country like India needs to be treated and detected early (3).Aims and Objectives: To detect and prevent congenital hypothyroidism in neonates born to mothers with hypothyroidism and their neonatal outcomes. To screen the neonates for congenital hypothyroidism.Methods: All the pregnant women visiting the antenatal OPD at KIMS Narketpally were screened for hypothyroidism during the first antenatal visit.The present study was conducted on 27 women with the diagnosis of hypothyroidism in pregnancy who came to the antenatal OPD and who were delivered at KIMS Narketpally.The neonates born to these mothers were screened for hypothyroidism on day 5 of life in order to detect congenital hypothyroidism in the neonate.Results: In the present study all the 27 mothers diagnosed with Hypothyroidism in pregnancy were taken. The TSH value of most of the mothers with Hypothyroidism was between 3 to 4.9 and most of the mothers were controlled on treatment with Tab.Thyronorm 25mcg.The neonates born to these mothers were screened on Day 5 of life to detect congenital Hypothyroidism. In the present study it showed that none of the neonates born to these Hypothyroid mothers had congenital hypothyroidism because of early diagnosis and Treatment of the mothers in the antenatal period.Conclusion: In the present study it was observed that all the neonates born to the mothers with Hypothyroidism had normal TSH values and none of the neonates had congenital hypothyroidism dues to early diagnosis and treatment.

The Pregnancy, Arsenic, and Immune Response (PAIR) Study in rural northern Bangladesh.

Arsenic exposure and micronutrient deficiencies may alter immune reactivity to influenza vaccination in pregnant women, transplacental transfer of maternal antibodies to the foetus, and maternal and infant acute morbidity. The Pregnancy, Arsenic, and Immune Response (PAIR) Study was designed to assess whether arsenic exposure and micronutrient deficiencies alter maternal and newborn immunity and acute morbidity following maternal seasonal influenza vaccination during pregnancy. The PAIR Study recruited pregnant women across a large rural study area in Gaibandha District, northern Bangladesh, 2018-2019. Prospective, longitudinal pregnancy and birth cohort. We conducted home visits to enrol pregnant women in the late first or early second trimester (11-17 weeks of gestational age). Women received a quadrivalent seasonal inactivated influenza vaccine at enrolment. Follow-up included up to 13 visits between enrolment and 3 months postpartum. Arsenic was measured in drinking water and maternal urine. Micronutrient deficiencies were assessed using plasma biomarkers. Vaccine-specific antibody titres were measured in maternal and infant serum. Weekly telephone surveillance ascertained acute morbidity symptoms in women and infants. We enrolled 784 pregnant women between October 2018 and March 2019. Of 784 women who enrolled, 736 (93.9%) delivered live births and 551 (70.3%) completed follow-up visits to 3 months postpartum. Arsenic was detected (≥0.02 μg/L) in 99.7% of water specimens collected from participants at enrolment. The medians (interquartile ranges) of water and urinary arsenic at enrolment were 5.1 (0.5, 25.1)μg/L and 33.1 (19.6, 56.5)μg/L, respectively. Water and urinary arsenic were strongly correlated (Spearman's ⍴=0.72) among women with water arsenic ≥ median but weakly correlated (⍴=0.17) among women with water arsenic < median. The PAIR Study is well positioned to examine the effects of low-moderate arsenic exposure and micronutrient deficiencies on immune outcomes in women and infants. NCT03930017.

Antifosfolipidni sindrom kod dece

Antiphospholipid syndrome is a multisystemic autoimmune disease characterized by the appearance of arterial and/or venous thrombosis, often in multiple locations, thrombocytopenia and repeated spontaneous abortions in affected pregnant women, due to the permanent presence of antiphospholipid antibodies. It can also occur in children and manifest itself in any period of childhood, from infancy, due to transplacental transfer of maternal antibodies, or de novo production of autoantibodies, to adolescence. Clinical manifestations described in adults can also occur in children but are modified by age characteristics, such as the immaturity of the immune or other organ systems, greater exposure to viral and bacterial infections, implementation of routine immunization, absence of thrombogenic risk factors common to adults (hypertension, arteriosclerosis, consumption of cigarettes, alcohol and/or oral contraceptives), as well as the absence of pregnancy. Antiphospholipid antibodies most often used in daily clinical work are anticardiolipin antibodies, anti-b2 glycoprotein I antibodies, and lupus anticoagulants. Pathogenic mechanisms have not been investigated in detail - it is assumed that they are similar to the adult form of the disease. However, there is rare evidence of the existence of specific patterns of immune response to individual antigenic components, which may lead to specific production of antiphospholipid antibodies during childhood. It is also important to note that these antibodies can be found in about 25% of healthy children. The Sapporo criteria are used to diagnose antiphospholipid syndrome in adults. They include clinical (vascular thrombosis, repeated fetal losses) and laboratory parameters (persistent presence of one of the antiphospholipid antibodies) in the IgG and/or IgM class, in medium or high titer. The updated Sapporo criteria also apply to children. They include the same laboratory and clinical criteria, except for pregnancy pathology. The differential diagnosis is very broad and requires extensive diagnostics. Considering the specificity of the disease in childhood, the recommendations valid for adults, modified to a certain degree, apply to the treatment of diseases in children.

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.

Upregulation of miR-181a-5p and miR-125b-2-3p in the Maternal Circulation of Fetuses with Rh-Negative Hemolytic Disease of the Fetus and Newborn Could Be Related to Dysfunction of Placental Function.

The transplacental transfer of maternal antibodies to the fetus is a critical mechanism for infant protection and perinatal disease. Hemolytic disease of the fetus and newborn (HDFN) is a representative fetal disease caused by transplacental transfer of maternal IgG antibodies. However, it is unclear whether placental-related miRNAs are expressed in Rh-HDFN. Through the investigation of the miR-181a-5p and miR-125b-2-3p levels in maternal plasma using qPCR, we found that both miR-181a-5p and miR-125b-2-3p were highly expressed in maternal plasma of newborns with Rh-HDFN compared with healthy controls, indicating the potential roles of these two miRNAs in Rh-HDFN. To demonstrate whether dysregulation of miR-125b-2-3p and miR-181a-5p contributes to Rh-HDFN development, we analyze the placental miRNA-/mRNA sequencing data (GSE73714) using weighted gene coexpression network analysis (WGCNA), miRNA target predictive databases, and DAVID (Database for Annotation, Visualization, and Integrated Discovery). The results showed that miR-125b-2-3p and miR-181a-5p could regulate several biological processes including cytoplasmic microtubule organization and angiogenesis. Moreover, core promoter sequence-specific DNA binding and protein binding were highly enriched molecular functions, indicating the potential roles of transcriptional regulation. Further pathway enrichment showed that miR-181a-5p and miR-125b-2-3p could regulate several biological pathways that were closely related to placental function, including the FoxO signaling pathway, focal adhesion, mTOR signaling pathway, and central carbon metabolism in cancer. In conclusion, the present results first revealed miRNA expression in the maternal circulation of newborns with Rh-HDFN, which could be caused by dysfunction of the placenta.

Transplacental Transfer of Maternal Antibody against SARS-CoV-2 and Its Influencing Factors: A Review.

Since the beginning of the coronavirus disease 2019 (COVID-19) outbreak, the disease has rapidly become a global threat. The constant emergence of new variants has increased the difficulty of controlling this disease. Vaccination is still considered the most effective method to prevent COVID-19. Vaccination has expanded to include children aged 3–17 years old, and some countries have lowered the age of vaccination to 6 months (for example, the United States). However, children under 3 years old are still not able to be vaccinated in most countries. In this study, we summarize the COVID-19 vaccination status in pregnant women, comprehensively elaborate on the status of maternal immune response and maternal antibody transfer after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination, and further analyze the possible influencing factors of maternal antibody transfer according to the currently available evidence on the topic. It was concluded that pregnant women develop an immune response and produce antibodies that can be transmitted through the placenta after vaccination, but more data are needed to determine the transfer rate and duration of these maternal antibodies and potential factors. The results provide a scientific basis for studying the protective effect of maternal antibodies on infants, formulating a vaccination strategy for pregnant women, and preventing SARS-CoV-2 infection in infants.

HIV-Associated Alterations of the Biophysical Features of Maternal Antibodies Correlate With Their Reduced Transfer Across the Placenta.

Human immunodeficiency virus (HIV) infection during pregnancy is associated with reduced transplacental transfer of maternal antibodies and increased risk of severe infections in children who are exposed and uninfected with HIV. The basis of this reduced transfer of maternal immunity has not yet been defined but could involve modifications in the biophysical features of antibodies. The objective of this study was to assess the impact of maternal HIV infection on the biophysical features of serum IgG and transplacental antibody transfer. Maternal serum IgG subclass levels, Fc glycosylation, Fc receptor (FcR) binding, and transplacental transfer of pathogen-specific maternal IgG were measured in pregnant women with HIV (WWH) and pregnant women testing negative for HIV (WNH) in Cape Town, South Africa. Maternal antibody profiles were strikingly different between pregnant WWH and WNH. Antibody binding to FcγR2a and FcγR2b, IgG1 and IgG3 antibodies, and agalactosylated antibodies were all elevated in WWH, whereas digalactosylated and sialylated antibodies were reduced compared to pregnant WNH. Antibody features that were elevated in WWH were also correlated with reduced transplacental transfer of vaccine antigen-specific antibodies. HIV infection is associated with marked alterations of biophysical features of maternal IgG and reduced placental transfer, potentially impairing antimicrobial immunity.

JMM Profile: Bordetella pertussis and whooping cough (pertussis): still a significant cause of infant morbidity and mortality, but vaccine-preventable.

Whooping cough (pertussis) is a highly contagious respiratory bacterial infection caused by Bordetella pertussis and is an important cause of morbidity and mortality worldwide, particularly in infants. Bordetella parapertussis can cause a similar, but usually less severe pertussis-like disease. Bordetella pertussis has a number of virulence factors including adhesins and toxins which allow the organism to bind to ciliated epithelial cells in the upper respiratory tract and interfere with host clearance mechanisms. Typical symptoms of pertussis include paroxysmal cough with characteristic whoop and vomiting. Severe complications and deaths occur mostly in infants. Laboratory confirmation can be performed by isolation, detection of genomic DNA or specific antibodies. Childhood vaccination is safe, effective and remains the best control method available. Many countries have replaced whole-cell pertussis vaccines (wP) with acellular pertussis vaccines (aP). Waning protection following immunisation with aP is considered to be more rapid than that from wP. Deployed by resource-rich countries to date, maternal immunisation programmes have also demonstrated high efficacy in preventing hospitalisation and death in infants by passive immunisation through transplacental transfer of maternal antibodies.

Low-level Plasmodium vivax exposure, maternal antibodies, and anemia in early childhood: Population-based birth cohort study in Amazonian Brazil.

Malaria causes significant morbidity and mortality in children under 5 years of age in sub-Saharan Africa and the Asia-Pacific region. Neonates and young infants remain relatively protected from clinical disease and the transplacental transfer of maternal antibodies is hypothesized as one of the protective factors. The adverse health effects of Plasmodium vivax malaria in early childhood-traditionally viewed as a benign infection-remain largely neglected in relatively low-endemicity settings across the Amazon. Overall, 1,539 children participating in a birth cohort study in the main transmission hotspot of Amazonian Brazil had a questionnaire administered, and blood sampled at the two-year follow-up visit. Only 7.1% of them experienced malaria confirmed by microscopy during their first 2 years of life- 89.1% of the infections were caused by P. vivax. Young infants appear to be little exposed to, or largely protected from infection, but children >12 months of age become as vulnerable to vivax malaria as their mothers. Few (1.4%) children experienced ≥4 infections during the 2-year follow-up, accounting for 43.4% of the overall malaria burden among study participants. Antenatal malaria diagnosed by microscopy during pregnancy or by PCR at delivery emerged as a significant correlate of subsequent risk of P. vivax infection in the offspring (incidence rate ratio, 2.58; P = 0.002), after adjusting for local transmission intensity. Anti-P. vivax antibodies measured at delivery do not protect mothers from subsequent malaria; whether maternal antibodies transferred to the fetus reduce early malaria risk in children remains undetermined. Finally, recent and repeated vivax malaria episodes in early childhood are associated with increased risk of anemia at the age of 2 years in this relatively low-endemicity setting. Antenatal infection increases the risk of vivax malaria in the offspring and repeated childhood P. vivax infections are associated with anemia at the age of 2 years.

Factors That Influence Infant Immunity and Vaccine Responses.

The neonatal period and early infancy are times of increased vulnerability to infection. The immune system of infants undergoes rapid changes and a number of factors can influence the maturation and function of the early infant immune system, amongst these factors are maternal infections and immunity. Infants who are HIV-exposed, but uninfected show important immune alterations, which are likely to be associated with the increased morbidity and mortality observed in these infants. Maternally derived antibodies are crucial in early life to protect infants from infection during the time when their own immune system is becoming more experienced and fully mature. However, maternal antibodies can also interfere with the infant's own antibody responses to primary vaccination. Preterm infants are particularly vulnerable to infection, having not had the opportunity to benefit from the transplacental transfer of maternal antibodies in late pregnancy. In addition, further differences have been observed in the innate and adaptive immune system between preterm and term infants. Here, we focus on maternal influences on the infant immune system, using HIV and maternal vaccination as examples and finish by considering how prematurity impacts infant immune responses to vaccination.

Trends in RPR Seropositivity among Children Younger than 2 Years in South Africa, 2010-2019.

A positive rapid plasma reagin (RPR) result in children under the age of 2 years indicates either passive transplacental transfer of maternal antibodies or active infection with syphilis (possible congenital syphilis). We describe trends in RPR seropositivity in this population using centralized laboratory data. A secondary analysis of laboratory data collected through the National Health Laboratory Service, Corporate Data Warehouse from 2010 to 2019 was conducted. Of the 127 150 children <2 years included in the analysis, 10 969 [8.6%; 95% confidence interval (95% CI) 85-88]) were RPR seropositive. RPR seropositivity increased from 6.5% to 13.0% between 2010 and 2019. Overall, the annual rate of RPR seropositivity was relatively stable between 2010 and 2018 with a range of 89-127/100 000 live births, increasing sharply to 165/100 000 livebirths in 2019. KwaZulu-Natal and North West provinces recorded the largest increases in annual seropositivity rate, while Eastern Cape and Western Cape had the most significant declines. Although this analysis is limited to laboratory results, in the absence of major changes in testing practices, there may be a rise in the burden of antenatal syphilis exposure in utero indicating an increase in maternal syphilis and syphilis transmission in the general population. South Africa needs to intensify Mother-to-Child Transmission of syphilis elimination efforts to reach the WHO target of ≤50 cases per 100 live births by 2030.

Benefits and Risks of IgG Transplacental Transfer.

Maternal passage of immunoglobulin G (IgG) is an important passive mechanism for protecting the infant while the neonatal immune system is still immature and ineffective. IgG is the only antibody class capable of crossing the histological layers of the placenta by attaching to the neonatal Fc receptor expressed at the level of syncytiotrophoblasts, and it offers protection against neonatal infectious pathogens. In pregnant women with autoimmune or alloimmune disorders, or in those requiring certain types of biological therapy, transplacental passage of abnormal antibodies may cause fetal or neonatal harm. In this review, we will discuss the physiological mechanisms and benefits of transplacental transfer of maternal antibodies as well as pathological maternal situations where this system is hijacked, potentially leading to adverse neonatal outcomes.

Safety and immunogenicity of three seasonal inactivated influenza vaccines among pregnant women and antibody persistence in their infants

ObjectiveInactivated influenza virus vaccines (IIVs) are recommended for all pregnant women in the United States. We conducted a prospective, randomized, double blind study of three licensed seasonal trivalent IIVs (IIV3s) to assess their safety and immunogenicity in pregnant women and determine the level and persistence of passively transferred maternal antibody in infants. Study design139 pregnant women ages 18–39 years and 14–33 weeks’ gestation, and 44 non-pregnant women, were randomized 1:1:1 to receive a single intramuscular dose of one of three licensed IIV3s (Agriflu®, Fluzone®, or Fluarix®) prior to the 2010–2011 influenza season. Reactogenicity, adverse events (AEs) and pregnancy outcomes were documented. Serum samples for hemagglutination inhibition (HAI) and neutralization antibody assays were collected prior to and 28 and 180 days after immunization. Maternal sera and cord blood were collected at the time of delivery and sera were obtained from 44 infants at 6 weeks of age. ResultsPregnant and non-pregnant women experienced similar frequency of injection site (92% and 86%, respectively) and systemic (95% and 87%, respectively) reactions, the majority of which were mild. There were no vaccine-associated maternal or infant serious AEs. Antibody responses to the three vaccine antigens were not different between pregnant and non-pregnant women. The ratios of cord blood (infant) to maternal HAI antibody titers at delivery ranged between 1.1 and 1.7 for each of the vaccine antigens. Influenza antibody concentrations in infants were 70–40% of the birth titer by 6 weeks of age. ConclusionsThe three IIV3s were well tolerated in pregnant women. Antibody responses were comparable in pregnant and non-pregnant women, and after second or third trimester vaccination. Transplacental transfer of maternal antibodies to the infant was efficient. However, antibody titers decline rapidly in the first 6 weeks of life.

Current Perspectives on Maternal Influenza Immunization

Pregnant women and young infants are more likely to experience severe complications associated with influenza infection and are at increased risk of hospitalization. Influenza vaccination during pregnancy produces antibodies which protect the mother against infection, and due to transplacental transfer of maternal antibodies before birth, it also protects the infant in the first few months of life. In many countries, influenza vaccination is recommended during pregnancy to protect mothers and their infants. In fact, influenza vaccine is the most widely used vaccine in pregnancy globally. When administered during pregnancy, the vaccine has been shown to be safe and effective for both mothers and their infants. Despite the health benefits, acceptance of influenza vaccine is low during pregnancy, indicating many women and infants are not protected against influenza. Concerted efforts are needed globally to improve the proportion of women and young infants who receive the health benefits of influenza vaccination.

Immunological and Clinical Benefits of Maternal Immunization Against Pertussis: A Systematic Review.

Infants are vulnerable to pertussis infection particularly before initiation of pertussis vaccination. Maternal pertussis vaccination during pregnancy has been introduced in a number of countries in order to confer on young infants indirect protection from the disease through transplacental transfer of maternal antibodies. We reviewed the evidence on the immunogenicity and efficacy of maternal pertussis vaccination during pregnancy. A systematic search of PubMed/MEDLINE, EMBASE, Scopus, Cochrane Database of Systematic Reviews, ProQuest, and Science Direct was undertaken to identify studies published between January 1995 and December 2018. This review was not specific to any particular pertussis vaccine but included applicable data on available pertussis vaccines administered to pregnant women. The search identified 40 publications for inclusion in this review. Vaccination during pregnancy elicited robust maternal immune responses against all vaccine antigens and resulted in high placental transfer of pertussis antibodies to the infant that persisted well beyond delivery. Vaccination during the second or early third trimesters was considered ideal for antibody quantity and functionality. Although blunting of immune responses to some antigens in the primary immunization series was documented in neonates born to women vaccinated during pregnancy, there was no apparent adverse effect on vaccine efficacy. Multiple studies conducted in diverse settings have confirmed the effectiveness of maternal pertussis vaccination during pregnancy in preventing pertussis in infants prior to receipt of their first primary vaccine dose and beyond. These findings collectively underscore the value of maternal pertussis vaccination during pregnancy in protecting vulnerable infants too young to be vaccinated.Funding Sanofi Pasteur.Plain Language Summary Plain language summary available for this article.

Increasing antepartum Tdap vaccine administration: A quality improvement initiative

The Centers for Disease Control and Prevention (CDC) recommends antepartum Tdap vaccination for women with each pregnancy to protect themselves and their vulnerable infants through transplacental transfer of maternal antibodies. Our aim was to increase the rate of antepartum Tdap vaccine administration by 20%. Obstetricians were surveyed to identify their present approaches and barriers to antepartum Tdap vaccine administration to help guide the development of our intervention. Limited staff training, lack of vaccine on site, and cost were the most commonly identified barriers. Using these survey responses, existing literature, and brainstorming conversations with colleagues, an interdisciplinary workgroup then created a fishbone analysis and developed a 5-step intervention to address these barriers: (1) educate providers and patients on Tdap and pertussis; (2) increase Tdap availability to all pregnant women; (3) remind staff of the established Tdap standing order to facilitate administration; (4) encourage obstetricians to offer Tdap; (5) transfer documentation of Tdap administration from office to hospital. To monitor changes in the process over 15 months of pre- and post-intervention, data were collected from monthly chart audits and a two-phase control chart was created. The main outcome measure was proportion of eligible women who received Tdap during current pregnancy. In the pre-intervention period, 362 of 636 eligible women (56.9%) received Tdap during their current pregnancy; in the post-intervention period, 457 of 708 eligible women (64.5%) received Tdap during their current pregnancy. This absolute difference of 7.6% (64.5% vs. 56.9%, p < 0.01) represents a 13.4% relative increase (64.5%/56.9%) in the proportion of clinically eligible pregnant women who received Tdap. This represents a clinically and statistically significant increase in the rate of antepartum Tdap immunization. More research is needed to further understand obstetric barriers and maternal refusal of antepartum Tdap administration.