Vaccines in pregnancy

Current recommendations for vaccines for patients planning pregnancy: a committee opinion

Encounters for infertility care are opportunities to assess and update immunization status. Individuals of reproductive age are often unaware of their need for immunization, their immunization status, and the potentially severe consequences of preventable disease on pregnancy outcome. The purpose of this American Society for Reproductive Medicine (ASRM) Practice Committee document is to summarize current recommendations regarding vaccinations for individuals of reproductive age. This document replaces the ASRM Practice Committee document titled "Vaccination guidelines for female infertility patients," last published in 2018 (Fertil Steril 2018;110:838-41).

Vaccine safety surveillance in Kenya using GAIA standards: A feasibility assessment of existing national and subnational research and program systems

BACKGROUND

Active surveillance systems for monitoring vaccine safety among pregnant women address some of the limitations of a current passive surveillance approach utilized in low- and middle-income countries (LMIC). However, few active surveillance systems in LMIC exist. Our study assessed the feasibility of utilizing three existing data collection systems in Kenya for active surveillance of maternal immunization and to assess the applicability of Global Alignment of Immunization Safety Assessment in pregnancy (GAIA) case definitions that were initially developed for clinical trials within these systems.

METHODS

We assessed applicability of GAIA case definition for maternal Tetanus Toxoid exposure, stillbirth, low birth weight, small for gestational age, Neonatal Invasive Blood Stream Infection (NIBSI), prematurity and neonatal death in two routine web-based health information systems (Kenya EMR and DHIS-2), and a web-based population-based pregnancy research platform (ANCOV1) in Kenya.

RESULTS

All three HIS were capable of reporting selected outcomes to varying degrees of GAIA certainty. The ANCOV platform was the most robust in collecting and collating clinical data for effective maternal pharmacovigilance. The utilization of facility- and district-aggregated data limits the usefulness of DHIS-2 in pharmacovigilance as currently operationalized. While the Kenya EMR contained individual level data and meets the key considerations for effective pharmacovigilance, it was used primarily for HIV care and treatment records in a small proportion of health facilities and would require additional resources to expand to all antenatal care facilities and to link maternal and infant records.

DISCUSSION

Population-based research studies may offer a responsive short-term option for implementing maternal vaccine pharmacovigilance in LMICs. However, the foundation exists for long-term capacity building within the national health electronic data systems to provide this critical service as well as ensure participation of the country in international studies on maternal vaccine safety.

Safety of COVID-19 vaccines in pregnancy: a Canadian National Vaccine Safety (CANVAS) network cohort study

Background

Pregnant individuals have been receiving COVID-19 vaccines following pre-authorisation clinical trials in non-pregnant people. This study aimed to determine the frequency and nature of significant health events among pregnant females after COVID-19 vaccination, compared with unvaccinated pregnant controls and vaccinated non-pregnant individuals.

Methods

We did an observational cohort study, set in seven Canadian provinces and territories including Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Yukon, and Prince Edward Island. Eligibility criteria for vaccinated individuals were a first dose of a COVID-19 vaccine within the previous 7 days; an active email address and telephone number; ability to communicate in English or French; and residence in the aforementioned provinces or territories. Study participants were pregnant and non-pregnant females aged 15–49 years. Individuals were able to participate as controls if they were unvaccinated and fulfilled the other criteria. Data were collected primarily by self-reported survey after both vaccine doses, with telephone follow-up for those reporting any medically attended event. Participants reported significant health events (new or worsening of a health event sufficient to cause work or school absenteeism, medical consultation, or prevent daily activities) occurring within 7 days of vaccination or within the past 7 days for unvaccinated individuals. We employed multivariable logistic regression to examine significant health events associated with mRNA vaccines, adjusting for age group, previous SARS-CoV-2 infection, and trimester, as appropriate.

Findings

As of Nov 4, 2021, 191 360 women aged 15–49 years with known pregnancy status had completed the first vaccine dose survey and 94 937 had completed the second dose survey. 180 388 received one dose and 94 262 received a second dose of an mRNA vaccine, with 5597 pregnant participants receiving dose one and 3108 receiving dose two, and 174 765 non-pregnant participants receiving dose one and 91 131 receiving dose two. Of 6179 included unvaccinated control participants, 339 were pregnant and 5840 were not pregnant. Overall, 226 (4·0%) of 5597 vaccinated pregnant females reported a significant health event after dose one of an mRNA vaccine, and 227 (7·3%) of 3108 after dose two, compared with 11 (3·2%) of 339 pregnant unvaccinated females. Pregnant vaccinated females had an increased odds of a significant health event within 7 days of the vaccine after dose two of mRNA-1273 (adjusted odds ratio [aOR] 4·4 [95% CI 2·4–8·3]) compared with pregnant unvaccinated controls within the past 7 days, but not after dose one of mRNA-1273 or any dose of BNT162b2. Pregnant vaccinated females had decreased odds of a significant health event compared with non-pregnant vaccinated females after both dose one (aOR 0·63 [95% CI 0·55–0·72]) and dose two (aOR 0·62 [0·54–0·71]) of any mRNA vaccination. There were no significant differences in any analyses when restricted to events which led to medical attention.

Interpretation

COVID-19 mRNA vaccines have a good safety profile in pregnancy. These data can be used to appropriately inform pregnant people regarding reactogenicity of COVID-19 vaccines during pregnancy, and should be considered alongside effectiveness and immunogenicity data to make appropriate recommendations about best use of COVID-19 vaccines in pregnancy.

Funding

Canadian Institutes of Health Research, Public Health Agency of Canada.

Investigating trends in those who experience menstrual bleeding changes after SARS-CoV-2 vaccination

Early in 2021, many people began sharing that they experienced unexpected menstrual bleeding after SARS-CoV-2 inoculation. We investigated this emerging phenomenon of changed menstrual bleeding patterns among a convenience sample of currently and formerly menstruating people using a web-based survey. In this sample, 42% of people with regular menstrual cycles bled more heavily than usual, while 44% reported no change after being vaccinated. Among respondents who typically do not menstruate, 71% of people on long-acting reversible contraceptives, 39% of people on gender-affirming hormones, and 66% of postmenopausal people reported breakthrough bleeding. We found that increased/breakthrough bleeding was significantly associated with age, systemic vaccine side effects (fever and/or fatigue), history of pregnancy or birth, and ethnicity. Generally, changes to menstrual bleeding are not uncommon or dangerous, yet attention to these experiences is necessary to build trust in medicine.

Vaccine implementation factors affecting maternal tetanus immunization in low- and middle-income countries: Results of the Maternal Immunization and Antenatal Care Situational Analysis (MIACSA) project

Objectives

To examine the characteristics of existing maternal tetanus immunization programmes for pregnant women in low- and middle-income countries (LMICs) and to identify and understand the challenges, barriers and facilitators associated with maternal vaccine service delivery that may impact the introduction and implementation of new maternal vaccines in the future.

Design

A mixed methods, cross sectional study with four data collection phases including a desk review, online survey, telephone and face-to-face interviews and in country visits.

Setting

LMICs.

Results

The majority of countries (84/95; 88%) had a maternal tetanus immunization policy. Countries with high protection at birth (PAB) were more likely to report tetanus toxoid-containing vaccine (TTCV) coverage targets > 90%. Less than half the countries included in this study had a TTCV coverage target of > 90%. Procurement and distribution of TTCV was nearly always the responsibility of the Expanded Programme on Immunization (EPI), however planning and management of maternal immunization was often shared between EPI and Maternal, Newborn and Child Health (MNCH) programmes. Receipt of TTCV at the same time as the antenatal care visit correlated with high PAB. Most countries (81/95; 85%) had an immunization safety surveillance system in place although only 11% could differentiate an adverse event following immunization (AEFI) in pregnant and non-pregnant women.

Conclusions

Recommendations arising from the MIACSA project to strengthen existing services currently delivering maternal tetanus immunization in LMICs include establishing and maintaining vaccination targets, clearly defining responsibilities and fostering collaborations between EPI and MNCH, investing in strengthening the health workforce, improving the design and use of existing record keeping for immunization, adjusting current AEFI reporting to differentiate pregnant women and endeavoring to integrate the provision of TTCV within ANC services where appropriate.

Diagnosis and Therapy Before Assisted Reproductive Treatments. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Register Number 015-085, February 2019) - Part 1, Basic Assessment of the Woman

Introduction Supporting and counselling couples with fertility issues prior to starting ART is a multidisciplinary diagnostic and therapeutic challenge. The first German/Austrian/Swiss interdisciplinary S2k guideline on "Diagnosis and Therapy Before Assisted Reproductive Treatments (ART)" was published in February 2019. This guideline was developed in the context of the guidelines program of the German Society of Gynecology and Obstetrics (DGGG) in cooperation with the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Aims One third of the causes of involuntary childlessness are still unclear, even if the woman or man have numerous possible risk factors. Because the topic is still very much taboo, couples may be socially isolated and often only present quite late to a fertility center. At present, there is no standard treatment concept, as currently no standard multidisciplinary procedures exist for the diagnostic workup and treatment of infertility. The aim of this guideline is to provide physicians with evidence-based recommendations for counselling, diagnostic workup and treatment. Methods This S2k guideline was developed on behalf of the Guidelines Commission of the DGGG by representative members from different professional medical organizations and societies using a structured consensus process. Recommendations The first part of this guideline focuses on the basic assessment of affected women, including standard anatomical and endocrinological diagnostic procedures and examinations into any potential infections. Other areas addressed in this guideline are the immunological workup with an evaluation of the patient's vaccination status, an evaluation of psychological factors, and the collection of data relating to other relevant factors affecting infertility. The second part will focus on explanations of diagnostic procedures compiled in collaboration with specialists from other medical specialties such as andrologists, human geneticists and oncologists.

Maternal immunization

Pregnant women, neonates, and infants are at higher risk for severe infections due to vaccine-preventable diseases. Very young infants rarely respond well to vaccination due to poor immunogenicity and interference from maternal antibody. Maternal immunization protects the mother and fetus from disease and protects the infant through transplacental antibody transfer through the first 6 months of life. Currently, immunizations routinely recommended during pregnancy include inactivated influenza, tetanus toxoid, and acellular pertussis vaccines. Promising maternal vaccine candidates in development include a group B streptococcus vaccine and a respiratory syncytial virus vaccine. Birth Defects Research 109:379-386, 2017. © 2017 Wiley Periodicals, Inc.

No. 357-Immunization in Pregnancy

OBJECTIVE

To review the evidence and provide recommendations on immunization in pregnancy.

OUTCOMES

Outcomes evaluated include effectiveness of immunization and risks and benefits for mother and fetus.

EVIDENCE

The Medline and Cochrane databases were searched for articles published up to January 2017 on the topic of immunization in pregnancy.

VALUES

The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the SOGC under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should result in more appropriate immunization of pregnant and breastfeeding women, decreased risk of contraindicated immunization, and better disease prevention.

RECOMMENDATIONS

Parasitic Infections in Pregnancy Decrease Placental Transfer of Antipneumococcus Antibodies

Many factors can influence maternal placental antibody transfer to the fetus, which confers important immune protection to the newborn infant. However, little is known about the effect of maternal parasitic infection on placental antibody transfer. To investigate this, we selected from a parent study of 576 pregnant Kenyan women four groups of women with term deliveries (≥37 weeks), including uninfected women (n = 30) and women with solo infections with malaria (n = 30), hookworm (n = 30), or schistosomiasis (n = 10). Maternal plasma at delivery and infant cord blood were tested via multiplex fluorescent bead assay for IgG against 10 pneumococcal serotypes (PnPs 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, and 23F), diphtheria toxoid, and Haemophilus influenzae type B. Infants born to mothers with prenatal malaria, hookworm, or Schistosoma haematobium infections were associated with a significantly reduced ratio of maternal to infant cord blood antibody concentration for Streptococcus pneumoniae serotypes 1, 4, 5, 6B, 7F, 9V, and 18C compared to infants of uninfected mothers. Anti-diphtheria toxoid and anti-H. influenzae type B IgG ratios were not significantly different among infection groups. Prenatal parasitic infections decrease the transfer of maternal IgG antibodies to infants for several serotypes of S. pneumoniae.

Effectiveness of maternal influenza immunization in young infants in Japan

BACKGROUND

Infants with influenza, particularly those younger than 1 year of age, are at high risk of developing a severe case or of dying. Recently, owing to the spread of pandemic influenza A (H1N1) 2009, the Advisory Committee on Immunization Practices recommended maternal immunization to reduce the risk of influenza infection in pregnant women and infants. Such reporting is rare in Japan. The aim of this study was therefore to investigate the effect on the newborn of influenza vaccination of pregnant women in Japan.

METHODS

The study included 200 infants who were born to healthy mothers at Kobayashi Ladies Clinic during influenza season from November 2010 to April 2011. The incidence of fever and laboratory-confirmed influenza was assessed in the infants for the 6 months after their birth.

RESULTS

Of the 200 infants, four were excluded from this study due to loss to follow up. The 106 infants in the group whose mothers received the influenza vaccine (vaccinated group) before parturition were compared with the 90 infants in the group whose mothers did not receive the influenza vaccine (non-vaccinated group). Fever was noted in 36 infants (34.0%) in the vaccinated group and in 47 infants (52.2%) in the non-vaccinated group (P < 0.007), and the incidence of influenza was 0 (0%) and 5 (5.6%), respectively (P = 0.019). The incidence of fever and influenza among infants was significantly lower in the vaccinated group compared with the non-vaccinated group.

CONCLUSIONS

Maternal influenza immunization should be actively recommended in Japan to protect newborns from influenza viruses.

A global survey of adverse event following immunization surveillance systems for pregnant women and their infants

Strengthening antenatal care as a platform for maternal immunization is a priority of the World Health Organization (WHO). Systematic surveillance for adverse events following immunization (AEFI) in pregnancy is needed to identify vaccine safety events. We sought to identify active and passive AEFI surveillance systems for pregnant women and infants. Representatives from all National Pharmacovigilance Centers and a convenience sample of vaccine safety experts were invited to complete a 14-item online survey in English, French or Spanish. The survey captured maternal immunization policies, and active and passive AEFI surveillance systems for pregnant women and infants in respondents' countries. The analysis was descriptive. We received responses from 51/185 (28%) invited persons from 47/148 (32%) countries representing all WHO regions, and low, middle and high-income countries. Thirty countries had national immunization policies targeting pregnant women. Eleven countries had active surveillance systems to detect serious AEFI in pregnant women and/or their infants, including six low and middle-income countries (LMIC). Thirty-nine countries had passive surveillance systems, including 23 LMIC. These active and passive surveillance programs cover approximately 8% and 56% of the worldwide annual birth cohort, respectively. Data from one active and four passive systems have been published. We identified 50 active and passive AEFI surveillance systems for pregnant women and infants, but few have published their findings. AEFI surveillance appears to be feasible in low and high resource settings. Further expansion of AEFI surveillance for pregnant women and sharing of vaccine safety information will provide additional evidence in support of maternal immunization policies.

Knowledge, attitudes and beliefs related to seasonal influenza vaccine among pregnant women in Thailand

BACKGROUND

In 2009, Thailand recommended pregnant women be prioritized for influenza vaccination. Vaccine uptake among Thai pregnant women is lower than other high-risk groups.

METHODS

During December 2012-April 2013, we conducted a cross-sectional survey of a convenience sample of Thai pregnant women aged ≥ 15 years attending antenatal clinics at public hospitals in 8 of 77 provinces. A self-administered questionnaire covered knowledge, attitudes, and beliefs related to influenza vaccination using the Health Belief Model. We examined factors associated with willingness to be vaccinated using log-binomial regression models.

RESULTS

The survey was completed by 1031 (96%) of 1072 pregnant women approached. A total of 627 (61%) women had heard about influenza vaccine and were included in the analysis, of whom 262 (42%) were willing to be vaccinated, 155 (25%) had received a healthcare provider recommendation for influenza vaccination and 25 (4%) had received the influenza vaccine during the current pregnancy. In unadjusted models, high levels of perceptions of susceptibility (prevalence ratio [PR] 1.5, 95% CI 1.2-2.0), high levels of belief in the benefits of vaccination (PR 2.3, 95% CI 1.7-3.1), moderate (PR 1.7, 95% CI 1.2-2.3) and high (PR 3.4, 95% CI 2.6-4.5) levels of encouragement by others to be vaccinated (i.e., cues to action) were positively associated with willingness to be vaccinated. Moderate (PR 0.5, 95% CI 0.4-0.7) and high levels of (PR 0.5, 95% CI 0.4-0.8) perceived barriers were negatively associated with willingness to be vaccinated. In the final adjusted model, only moderate (PR 1.5, 95% CI 1.1-2.0) and high levels of cues to action (PR 2.7, 95% CI 2.0-3.6) were statistically associated with willingness to be vaccinated.

CONCLUSION

Cues to action were associated with willingness to be vaccinated and can be used to inform communication strategies during the vaccine campaign to increase influenza vaccination among Thai pregnant women.

Recent developments in the understanding and use of anthrax vaccine adsorbed: achieving more with less

Anthrax Vaccine Adsorbed (AVA, BioThrax™) is the only Food and Drug Administration (FDA) approved vaccine for the prevention of anthrax in humans. Recent improvements in pre-exposure prophylaxis (PrEP) use of AVA include intramuscular (IM) administration and simplification of the priming series to three doses over 6 months. Administration IM markedly reduced the frequency, severity and duration of injection site reactions. Refinement of animal models for inhalation anthrax, identification of immune correlates of protection and cross-species modeling have created opportunities for reductions in the PrEP booster schedule and were pivotal in FDA approval of a post-exposure prophylaxis (PEP) indication. Clinical and nonclinical studies of accelerated PEP schedules and divided doses may provide prospects for shortening the PEP antimicrobial treatment period. These data may assist in determining feasibility of expanded coverage in a large-scale emergency when vaccine demand may exceed availability. Enhancements to the AVA formulation may broaden the vaccine's PEP application.

Maternal Influenza Vaccination and Risk for Congenital Malformations: A Systematic Review and Meta-analysis

OBJECTIVE

To systematically summarize the literature on maternal influenza vaccination and the risk for congenital malformations using the methodology of meta-analysis.

DATA SOURCES

PubMed, Scopus, and Embase databases (up to December 2014) as well as ClinicalTrials.gov (May 2015) and references of relevant articles were searched. The search strategy included combinations of the terms "influenza," "vaccin*," "pregnan*," "safe*," "adverse," "congenital," "malformation," "defect," and "anomal*."

METHODS OF STUDY SELECTION

Eligible studies examined the association between antepartum or preconceptional maternal immunization with inactivated influenza vaccines (seasonal trivalent or monovalent H1N1) and the risk for congenital malformations. Studies with no or inappropriate control group (comparison with population background rates or other vaccine types) were excluded.

TABULATION, INTEGRATION, AND RESULTS

The risk for congenital anomalies after influenza vaccination was examined in 15 studies: 14 cohorts (events per vaccinated compared with unvaccinated: 859/32,774 [2.6%] compared with 7,644/245,314 [3.1%]) and one case-control study (vaccinated per cases compared with controls: 1,351/3,618 [37.3%] compared with 511/1,225 [41.7%]). Eight studies reported on first-trimester immunization (events per vaccinated compared with unvaccinated: 258/4,733 [5.4%] compared with 6,470/196,054 [3.3%]). No association was found between congenital defects and influenza vaccination at any trimester of pregnancy (odds ratio [OR] 0.96, 95% confidence interval 0.86-1.07; 15 studies; I2=36) or at the first trimester (OR 1.03, 0.91-1.18; eight studies; I2=0). When assessing only major malformations, no increased risk was detected after immunization at any trimester (OR 0.99, 0.88-1.11; 12 studies; I2=31.5) or at the first trimester (OR 0.98, 0.83-1.16; seven studies; I2=0). Neither adjuvanted (OR 1.06, 0.95-1.20; five studies; I2=18.8) nor unadjuvanted vaccines (OR 0.89, 0.75-1.04; seven studies; I2=22.6) were associated with an increased risk for congenital defects.

CONCLUSION

This systematic review did not indicate an increased risk for congenital anomalies after maternal influenza immunization adding to the evidence base on the safety of influenza vaccination in pregnancy.

Introduction. Maternal immunization - Promises and concerns

In this issue of Vaccine, the maternal immunization platform as an approach to protect mothers and infants against diverse pathogens is presented. Potential vaccine targets and the safety, science, trial designs, ethical considerations, and international perspectives focusing on low and middle income countries (LMIC) are discussed. This information provides a timely update because maternal immunization is increasingly being considered as an intervention to prevent maternal and/or neonatal disease. Prioritization of vaccine targets for maternal immunization by researchers, public health officials and health care workers needs to begin now.

Designs of two randomized, community-based trials to assess the impact of influenza immunization during pregnancy on respiratory illness among pregnant women and their infants and reproductive outcomes in rural Nepal

Background

Among the most important causes of illness and death in both pregnant women and their newborn infants are respiratory infections including influenza. Pregnant women in North America have a 4 to 5 fold excess rate of hospitalization compared to non-pregnant women. Rates of infant hospitalization associated with influenza are much higher than in their mothers. Fully half of children hospitalized for influenza in the US are in the age group 0–5 months, a group where no vaccine is licensed. Data on influenza are much fewer in low income countries where the risks of serious morbidity and mortality are much higher. A recent trial in Bangladesh suggested that influenza immunization in pregnant women could have important protective effects against influenza in both mothers and their infants. These trials were designed to provide additional evidence about the effect of influenza vaccination in pregnancy in settings where influenza may circulate for up to ten months/year.

Methods/Design

We conducted a consecutive pair of community-based, placebo-controlled, randomized trials of influenza vaccination of pregnant women in a rural district in southern Nepal. Two trials were conducted to insure, as much as possible, the match of circulating strains with those included in the vaccine. Eligible women included all who were or became pregnant over a one year period. Each trial included a one year cohort of pregnant women who were individually randomized to the influenza vaccine available at the time of their enrollment or placebo. Exclusions included a history of allergy to vaccine components, prior influenza vaccine receipt, and for the second trial, participation in the first trial. Morbidity was assessed on a weekly basis for women throughout pregnancy and through 180 days post-partum. Infants were followed weekly through 180 days. Primary outcomes included: 1) incidence of influenza like illness in women, 2) incidence of laboratory confirmed influenza illness in infants, and 3) birthweight among newborn infants.

Discussion

We have presented the design and methods of two randomized trials of influenza immunization of pregnant women.

Trial registration

Clinicaltrials.gov: (NCT01034254).

Immunization in pregnancy

OBJECTIVE

To review the evidence and provide recommendations on immunization in pregnancy.

OUTCOMES

Outcomes evaluated include effectiveness of immunization, risks and benefits for mother and fetus.

EVIDENCE

The Medline and Cochrane databases were searched for articles published up to June 2008 on the topic of immunization in pregnancy.

VALUES

The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should result in more appropriate immunization of pregnant and breastfeeding women, decreased risk of contraindicated immunization, and better disease prevention.

RECOMMENDATIONS

The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1). (1) All women of childbearing age should be evaluated for the possibility of pregnancy before immunization. (III-A). (2) Health care providers should obtain a relevant immunization history from all women accessing prenatal care. (III-A). (3) In general, live and/or live-attenuated virus vaccines should not be administered during pregnancy, as there is a, largely theoretical, risk to the fetus. (II-3B). (4) Women who have inadvertently received immunization with live or live-attenuated vaccines during pregnancy should not be counselled to terminate the pregnancy because of a teratogenic risk. (II-2A). (5) Non-pregnant women immunized with a live or live-attenuated vaccine should be counselled to delay pregnancy for at least four weeks. (III-B). (6) Inactivated viral vaccines, bacterial vaccines, and toxoids can be used safely in pregnancy. (II-1A). (7) Women who are breastfeeding can still be immunized (passive-active immunization, live or killed vaccines). (II-1A) (8) Pregnant women should be offered the influenza vaccine (including H1N1 vaccine, when it is available) when they are pregnant during the influenza season. (II-1A). (9) Pregnant women with suspected or documented H1N1 infection should be treated with oseltamivir (Tamiflu, 75 mg twice daily for 5 days) within 48 hours of onset of symptoms. (III-B).

Maternal immunization

Maternal immunization has the potential to protect the pregnant woman, fetus, and infant from vaccine-preventable diseases. Maternal immunoglobulin G is actively transported across the placenta, providing passive immunity to the neonate and infant prior to the infant's ability to respond to vaccines. Currently inactivated influenza, tetanus toxoid, and acellular pertussis vaccines are recommended during pregnancy. Several other vaccines have been studied in pregnancy and found to be safe and immunogenic and to provide antibody to infants. These include pneumococcus, group B Streptococcus, Haemophilus influenzae type b, and meningococcus vaccines. Other vaccines in development for potential maternal immunization include respiratory syncytial virus, herpes simplex virus, and cytomegalovirus vaccines.

Vaccinations given during pregnancy, 2002-2009: a descriptive study

BACKGROUND

A number of studies have described influenza vaccination coverage during pregnancy but few publications have described rates of other vaccinations.

PURPOSE

To describe vaccination rates during pregnancy in the Vaccine Safety Datalink (VSD), with particular focus on vaccinations contraindicated during pregnancy.

METHODS

Pregnancies ending in 2002 through 2009 and vaccinations administered during these pregnancies were identified in the VSD. Vaccination rates per 1000 pregnancies during the study period were calculated by vaccine type, recommendation category, pregnancy year, maternal age, and trimester. Analyses were conducted in 2012-2013.

RESULTS

In the VSD, 669,695 pregnancies and 141,389 vaccinations were identified. Trivalent inactivated influenza (TIV) was the most commonly administered vaccination (174.1 doses per 1000 pregnancies) and was most often administered during the 2nd and 3rd trimesters. The most common vaccines in the "consider if indicated" category were tetanus-diphtheria (6.1 per 1000) and hepatitis B (3.7 per 1000). Contraindicated vaccination was infrequent, and the majority of these were measles-mumps-rubella (MMR) (1.2 per 1000); varicella (1.0 per 1000); and live-attenuated influenza vaccine (LAIV) (0.3 per 1000). Both "consider if indicated" and contraindicated vaccines were more frequently administered during early pregnancy.

CONCLUSIONS

TIV was the most commonly administered vaccine. With the exception of TIV, other vaccines were most frequently administered during early pregnancy and among younger women, suggesting that vaccination may occur when the woman and/or provider are unaware of the pregnancy. Contraindicated vaccines were infrequently administered during pregnancy; however, given that some women received contraindicated vaccines later in pregnancy, clearer recommendations and improved provider education may be needed.

HFcRn-mediated transplacental immunoglobulin G transport: protection of and threat to the human fetus and newborn

In human newborns, endogenous levels of plasma immunoglobulin G (IgG) begin to rise slowly after birth following exposure to the environment. For immunoprotection during fetal and early neonatal life, maternal IgG is provided by transplacental transport. While cellular immunoprotective IgG effects are mainly triggered by FcγRI, -RII and -RIII, transplacental IgG transfer is mediated by the MHC class I-like neonatal Fc-receptor, hFcRn. This compact review explains the mechanism of hFcRn-mediated IgG transcytosis across the placental barrier - syncytiotrophoblast and fetal endothelial cells. Restrictions of this IgG transport are summarized. These include IgG subclass discrimination and limited IgG transport before the third trimester that can cause insufficient protection from infections of preterm (≤ 35 th week) delivered babies. As hFcRn does not discriminate beneficial from hazardous IgGs, maternal auto- and alloimmune as well as therapeutic antibodies can reach the fetus. The consequences including severe diseases of the newborn are summarized in this article.

Vaccination guidelines for female infertility patients: a committee opinion

Encounters for infertility care are opportunities to assess and update immunization status. Women of reproductive age are often unaware of their need for immunization, their own immunization status, and the potentially serious consequences of preventable disease on pregnancy outcome. The purpose of this ASRM Practice Committee document is to summarize current recommendations regarding vaccinations for women of reproductive age. This document replaces the ASRM Practice Committee document of the same name last published in Fertil Steril 2008;90:S169-71.

Influenza immunization in pregnancy: overcoming patient and health care provider barriers

Seasonal influenza imparts disproportionate morbidity and death to pregnant women. Immunization against influenza is the most effective intervention to mitigate the burden of influenza disease during pregnancy; nevertheless, immunization rates remain suboptimal in this patient population. Therefore, there is a clear need for strategies to optimize influenza vaccination among pregnant women. We reviewed potential patient and health care provider barriers to influenza immunization and propose effective strategies for overcoming them.

Safety of hepatitis B, pneumococcal polysaccharide and meningococcal polysaccharide vaccines in pregnancy: a systematic review

Immunization during pregnancy has the potential to protect the mother and the newborn from preventable diseases. Current recommendations suggest that inactivated vaccines might be considered during pregnancy when the benefits outweigh the risks. In this review, we aimed to evaluate the safety of hepatitis B (HB) vaccine, pneumococcal polysaccharide vaccine (PPSV) and meningococcal polysaccharide vaccine (MPSV) administration during pregnancy by systematically reviewing the available evidence in PubMed and Scopus databases, as well as postmarketing surveillance data (including the Vaccine Adverse Event Reporting System [VAERS] database). A total of 18 studies were eligible for inclusion in the review. Six studies provided data on HB vaccine, six on PPSV and three on MPSV; three additional studies compared PPSV with MPSV. Additionally, 91 reports on vaccinations of pregnant women were identified from postmarketing surveillance data (88 on HB vaccine, 2 on PPSV, 1 on MPSV). The most common complaints were local reactions, including tenderness and swelling. Overall, immunization during pregnancy did not seem to be associated with a teratogenic effect on the fetus, preterm labour or spontaneous abortion. However, the lack of randomized, placebo-controlled trials, or even large cohort studies, in addition to the inherent limitations of the reviewed observational studies with small statistical power, precluded safe conclusions. Large, prospective, population-based cohort studies are needed to elucidate this issue.

Risk perceptions, worry, or distrust: what drives pregnant women's decisions to accept the H1N1 vaccine?

To determine how risk perceptions, worry, and distrust relate to pregnant women's intentions to accept the H1N1 vaccine. Cross-sectional survey of 173 pregnant women recruited from two OB/GYN practices at an urban academic medical center. Survey items were adapted from validated measures of risk, worry, and health care distrust. Vaccination intention was analyzed as a dichotomous variable. Analyses were with student's t tests, chi squared tests, and logistic regression. Study participants were, on average, 25.6 years old with parity=2.8. 55% of respondents were Black; 32% completed a high school diploma or less; and half were publically or un- insured. 63% of the respondents reported that they "definitely" or "probably" would accept the H1N1 vaccine. Intention to receive the H1N1 vaccine did not vary by sociodemographic factors nor by source of health information. In univariate analysis, intention was related to higher risk perceptions about probability of and susceptibility to H1N1 influenza (57.9 vs. 31.8%, P=.001 and 67.0 vs. 45.3%, P=.005, respectively), worry about getting H1N1 influenza (48.1 vs. 15.6%, P=<.001), and less distrust in the health care system (mean score 1.07 vs. 1.51, P<.001). In multivariable analysis, only worry about getting H1N1 was related to vaccination intention (OR=3.43, P=.04). Worry about acquiring disease was a stronger predictor of vaccine intention than risk perceptions, distrust, or worry about vaccine safety. With growing numbers of vaccines being offered during pregnancy and immediately postpartum, these results have important implications for future vaccination intervention, education, and messaging efforts in urban settings.

IgG placental transfer in healthy and pathological pregnancies

Placental transfer of maternal IgG antibodies to the fetus is an important mechanism that provides protection to the infant while his/her humoral response is inefficient. IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells. There is evidence that IgG transfer depends on the following: (i) maternal levels of total IgG and specific antibodies, (ii) gestational age, (iii) placental integrity, (iv) IgG subclass, and (v) nature of antigen, being more intense for thymus-dependent ones. These features represent the basis for maternal immunization strategies aimed at protecting newborns against neonatal and infantile infectious diseases. In some situations, such as mothers with primary immunodeficiencies, exogenous IgG acquired by intravenous immunoglobulin therapy crosses the placenta in similar patterns to endogenous immunoglobulins and may also protect the offspring from infections in early life. Inversely, harmful autoantibodies may cross the placenta and cause transitory autoimmune disease in the neonate.

Novel pandemic A (H1N1) influenza vaccination among pregnant women: motivators and barriers

We sought to examine motivators and barriers related to monovalent 2009 influenza A (H1N1) vaccination among pregnant women. We conducted a national poll of pregnant women using a random online sample (237) and opt-in supplement (277). In all, 42% of pregnant women reported getting the vaccine. Vaccination was positively associated with attitudinal factors including believing the vaccine is very safe or benefits the baby, and with provider recommendations. Women in racial/ethnic minority groups, women with less education, and women <35 years were less likely to get the vaccine and had differing views and experiences. Despite H1N1 vaccination rates that are higher than past seasonal influenza rates, barriers like safety concerns may persist in a pandemic. Messaging from providers that encourages women to believe the vaccine is very safe and benefits their baby may be compelling. Messaging and outreach during future pandemics may require customization to increase vaccination among high-risk groups.

Maternal immunization to modulate the development of allergic response and pathogen infections

This article reviews recent experimental approaches of preventive strategies regarding allergy and infections by pathogens, particularly in early childhood, by targeting maternal immunomodulation. Basic research is essential to understand maternal vaccination as a strategy to control allergic disease and bacterial and viral infections; thus, providing support for future translational research. The environmental stimuli and host genetic factors, along with maternal influences in early life when immune systems are developing and during postnatal life, are essential for the decision between tolerance induction or allergen sensitization. Maternal immunomodulation strategies should serve as a challenge when attempting to halt the spread of allergy responses and viral infections, until the innate and adaptive arms of the immune system of the neonates are competent.

Vaccination in Pregnancy

Vaccination is one of the most effective strategies employed to prevent morbidity and mortality from infectious diseases. Pregnancy is considered to be a time when women have consistent contact with their healthcare providers and it presents an opportunity for providers to review their immunization status and to advocate for appropriate vaccination antepartum and in the immediate postpartum period. All forms of immunization, with the exception of live viral or live bacterial vaccines are generally considered to be safe for administration during pregnancy. It is important that healthcare providers counsel pregnant women about the benefits of receiving the vaccines that are recommended during pregnancy as well as the potential risks to the developing fetus. It is imperative that obstetricians and primary care providers are aware of and implement the vaccination guidelines for women, both during pregnancy and in the postpartum period.

Influenza vaccine given to pregnant women reduces hospitalization due to influenza in their infants

BACKGROUND

Infants aged <12 months are at high risk of hospitalization for influenza. Influenza vaccine is recommended for pregnant women and for most children; however, no vaccine is approved for infants aged <6 months. Effective approaches are needed to protect this vulnerable population. Vaccination of women during pregnancy may protect the infant through transfer of antibodies from the mother. Few studies have examined the effectiveness of this strategy, and those studies produced mixed results.

METHODS

In a matched case-control study, case patients were infants aged <12 months admitted to a large urban hospital in the northeastern United States because of laboratory-confirmed influenza from 2000 to 2009. For each case, we enrolled 1 or 2 control subjects who were infants who tested negative for influenza and matched cases by date of birth and date of hospitalization (within 4 weeks). Vaccine effectiveness was calculated on the basis of matched odds ratios and was adjusted for confounding.

RESULTS

The mothers of 2 (2.2%) of 91 case subjects and 31 (19.9%) of 156 control subjects aged <6 months, and 1 (4.6%) of 22 case subjects and 2 (5.6%) of 36 control subjects aged ≥6 months, had received influenza vaccine during pregnancy. The effectiveness of influenza vaccine given to mothers during pregnancy in preventing hospitalization among their infants, adjusted for potential confounders, was 91.5% (95% confidence interval [CI], 61.7%-98.1%; P = .001) for infants aged <6 months. The unadjusted effectiveness was 90.7% (95% CI, 59.9%-97.8%; P = .001).

CONCLUSIONS

Influenza vaccine given to pregnant women is 91.5% effective in preventing hospitalization of their infants for influenza in the first 6 months of life.

Is routine influenza immunization warranted in early pregnancy?

Routine influenza immunization is recommended for select groups because of their higher risk of serious influenza outcomes. Based on that benefit-risk framework, we assessed whether routine administration of trivalent inactivated influenza vaccine (TIV) is warranted in pregnancy, beginning in 1st trimester. Higher maternal mortality due to influenza was extensively described during the 1918 and 1957 pandemics, but epidemiologic evidence thereafter is limited to case reports and a single ecologic analysis during a single season. Significantly elevated rates of hospitalization have been reported with seasonal influenza beginning in 1st trimester among women with select comorbidities and during the 2nd half of normal pregnancy. TIV protection against serious outcomes in pregnant women has not yet been shown. Although harm has also not been shown, sample size to date is insufficient to assert TIV safety in 1st trimester. Benefit-risk analysis suggests influenza immunization may be warranted at any stage of pregnancy during certain pandemics and annually among women with select comorbidities. TIV may also be warranted to protect women against influenza-related hospitalization during the 2nd half of normal pregnancy. Evidence is otherwise insufficient to recommend routine TIV as the standard of practice for all healthy women beginning in early pregnancy.

Vaccination guidelines for female infertility patients

Encounters for infertility care are opportunities to assess and update immunization status. Women of reproductive age are often unaware of their need for immunization, their own immunization status, and the potentially serious consequences of preventable disease on pregnancy outcome. The purpose of this ASRM Practice Committee document is to summarize current recommendations regarding vaccinations for women of reproductive age.

Pre-travel vaccination and medical prophylaxis in the pregnant traveler

BACKGROUND

Practitioners are often fearful of giving vaccinations and prophylactic medications to pregnant travelers. And yet pregnancy is often a time of heightened danger from travel-related infections and illnesses.

METHOD

Literature search and communication with researchers.

RESULTS

With a few exceptions, there is little systematic research regarding the use of prophylactic medications and vaccines during pregnancy. Case reports and small studies do, however, indicate an increased risk in pregnancy from many of the preventable illnesses, and there is some data to support the use of preventive measures.

CONCLUSIONS

The authors present some non-medical interventions that may be used to limit exposure to a number of disease processes. They then review the available information regarding the safety and efficacy of routine and travel-related vaccines as well as prophylactic medications for malaria, diarrhea, motion sickness and altitude sickness. When there are no obstetrical or medical contraindications, travel-related illness can usually be safely prevented during pregnancy in much the same ways as in the non-pregnant state.

Birth defects among infants born to women who received anthrax vaccine in pregnancy

In response to bioterrorism threats, anthrax vaccine has been used by the US military and considered for civilian use. Concerns exist about the potential for adverse reproductive health effects among vaccine recipients. This retrospective cohort evaluated birth defects, in relation to maternal anthrax vaccination, among all infants born to US military service women between 1998 and 2004. Department of Defense databases defined maternal vaccination and infant diagnoses; multivariable regression models described potential associations between anthrax vaccination and birth defects in liveborn infants. Among 115,169 infants born to military women during this period, 37,140 were born to women ever vaccinated against anthrax, and 3,465 were born to women vaccinated in the first trimester of pregnancy. Birth defects were slightly more common in first trimester-exposed infants (odds ratio = 1.18, 95% confidence interval: 0.997, 1.41) when compared with infants of women vaccinated outside of the first trimester, but this association was statistically significant only when alternative referent groups were used. Although the small observed association may be unlikely to represent a causal relation between vaccination in early pregnancy and birth defects, this information should be considered when making decisions about administering anthrax vaccine to pregnant women.

A cross-sectional study of maternity care providers' and women's knowledge, attitudes, and behaviours towards influenza vaccination during pregnancy

BACKGROUND

Pregnant women are at increased risk of influenza-related complications, but research to examine barriers to maternal influenza vaccination has been limited and no studies have assessed the barriers to vaccinating pregnant women in Canada.

OBJECTIVES

The objectives of the study were to assess (1) how the knowledge, attitudes, and beliefs of Canadian maternity care providers influence their discussion and recommendation patterns, and (2) how the knowledge, attitudes, and beliefs of Canadian women, along with care providers' recommendations, influence their acceptance of influenza vaccine during pregnancy.

METHODS

Two cross-sectional surveys, one of maternity care providers and one of postpartum women, were carried out between December 1, 2003, and March 31, 2004.

RESULTS

Multivariate logistic analysis demonstrated that high levels of provider knowledge about maternal vaccination (OR = 2.64; 95% CI 1.56-4.46), positive attitudes towards influenza vaccination (OR = 2.29; 95% CI 1.43-3.68), and increased age (OR = 1.03; 95% CI 1.02-1.06) were associated with recommending influenza vaccine to pregnant women. Similarly, women who had higher levels of knowledge about maternal vaccination (OR = 3.46; 95% CI 1.31-9.17), positive attitudes towards influenza vaccination (OR = 4.69; 95% CI 1.63-13.5), and a recommendation from their maternity care provider (OR = 32.3; 95% CI 10.4-100) were more likely to be vaccinated during pregnancy. One of the most striking provider barriers identified was uncertainty about who bears responsibility for discussion, recommendation, and vaccination.

CONCLUSION

Maternity care provider recommendation was found to be an important element in increasing influenza vaccination rates during pregnancy. Clarity about responsibility for providing vaccine is needed.

Normal establishment of virus-specific memory CD8 T cell pool following primary infection during pregnancy

Suppression of cell-mediated immunity has been proposed as a mechanism that promotes maternal tolerance of the fetus but also contributes to increased occurrence and severity of certain infections during pregnancy. Despite decades of research examining the effect of pregnancy on Ag-specific T cell responses, many questions remain. In particular, quantitative examination of memory CD8 T cell generation following infection during pregnancy remains largely unknown. To examine this issue, we evaluated the generation of protective immunity following infection during pregnancy with a nonpersistent strain of lymphocytic choriomeningitis virus (LCMV) in mice. The CD8 T cell response to LCMV occurred normally in pregnant mice compared with the nonpregnant cohort with rapid viral clearance in all tissues tested except for the placenta. Despite significant infiltration of CD8 T cells to the maternal-fetal interface, virus persisted in the placenta until delivery. Live pups were not infected and generated normal primary immune responses when challenged as adults. Memory CD8 T cell development in mice that were pregnant during primary infection was normal with regards to the proliferative capacity, number of Ag-specific cells, cytokine production upon re-stimulation, and the ability to protect from re-infection. These data suggest that virus-specific adaptive memory is normally generated in mice during pregnancy.

The case for maternal vaccination against pertussis

Despite high vaccine coverage, the incidence of pertussis is increasing in a number of countries. Particularly alarming is the increase of pertussis in infants too young to be (fully) vaccinated, because the highest morbidity and mortality is observed in this category. Maternal vaccination offers the possibility to protect infants from birth until immunity is induced by active vaccination, and has been shown to be effective and safe for tetanus over long periods of time. Maternal vaccination studies with whole-cell pertussis vaccines have not shown serious adverse effects in mother and child. In one study, protection of newborn babies was found. Additional support for the efficacy of maternal vaccination comes from studies showing that transfer of antibodies confers protection against pertussis. Maternal vaccination might be an effective way to decrease morbidity and mortality caused by pertussis in newborn babies.

Vaccination guidelines for female infertility patients

Encounters for infertility care are opportunities to assess and update immunization status. Women of reproductive age are often unaware of their need for immunization, their own immunization status, and the potentially serious consequences of preventable disease on pregnancy outcome. The purpose of this ASRM Practice Committee document is to summarize current recommendations regarding vaccinations for women of reproductive age.

The pregnant traveller

Counselling pregnant women seeking advice about travel should begin with a frank, in-depth discussion about their contemplated trip. While most travel during pregnancy is relatively safe, some women should be urged not to go on their planned trip, or to change their itineraries. But some women are not receptive to such advice. Much of today's popular culture preaches that pregnancy is a normal phase of life, not a health issue, and that restrictions placed on women during pregnancy by the medical profession are largely unnecessary. The women must truly and totally understand potential risks and realise that medical science does not have all the answers, especially as far as risks to the foetus are concerned. The women should be aware that travel may remove them from access to medical care, require immunisations and prophylactic medications, involve long hours sitting in aircraft, necessitate dietary restrictions at the destination, and expose them to extremes of climate, to mention just a few.

Influenza Vaccination During Pregnancy: Opinions and Practices of Obstetricians in an Urban Community

BACKGROUND

Influenza vaccination is recommended for all women who will be pregnant during the influenza season; however, little is known about the attitudes of physicians regarding vaccination of pregnant women.

METHODS

We conducted a survey of all the fellows of the American College of Obstetricians and Gynecologists (ACOG) who live and practice in Nashville, Tennessee, focusing on physician knowledge, practices, and opinions regarding influenza vaccination of pregnant

RESULTS

Thirty-seven of 58 (64%) eligible physicians participated. Obstetrician opinion on the earliest influenza vaccine administration for healthy pregnant women was 62% during the second trimester, 32% during the first trimester, and 6% felt that the vaccine should not be given during pregnancy. All physicians responded that pregnant women with an underlying high risk condition should be vaccinated.

CONCLUSION

Practicing obstetricians differ in their preferences regarding the timing of influenza vaccine administration in pregnant women. Obstetrician and patient opinion and practice should be studied and considered in developing vaccine guidelines and vaccine implementation strategies.

A new animal model of Bordetella pertussis infection and immunity

Bordetella pertussis is a strictly human pathogen. Experimental infection of other animals can occur with large inoculating doses; rat, mice and primate models have been used to study pathogenesis and immunity. Recently, it was shown that newborn piglets are susceptible to B. pertussis. Lung pathophysiology of infected piglets was similar to that of human infants that develop bronchopneumonia. Piglets and infants are anatomically similar and maternal antibodies are transferred and secreted by a similar mechanism. This model could be valuable for studying the roles of passively and actively acquired immunity against B. pertussis.