Vaccines and pregnancy: past, present, and future

Acceptance of Routine Vaccines in Pregnancy during the COVID-19 Pandemic

OBJECTIVE

 This study aimed to evaluate the rates of vaccination against infectious diseases (Tetanus, Diphtheria, and Pertussis [Tdap] and influenza) in pregnancy during the coronavirus disease 2019 (COVID-19) pandemic compared to contemporary historical controls.

STUDY DESIGN

 This was a retrospective cohort study comparing rates of Tdap and influenza vaccination in pregnant people who received care at NYU Langone Health and delivered from September 1, 2020, to January 31, 2021 ("COVID cohort") to the same period the prior year ("2019 cohort"). Demographic information, trimester of initiation of prenatal care, insurance status, and medical comorbidities were evaluated. Outcomes were analyzed using chi-square, Fisher's exact test, and multivariable logistic regression, with significance of p < 0.05.

RESULTS

 In total, 1,713 pregnant people were included. Compared to historical controls, the COVID cohort differed in age, race, timing of initiation of prenatal care, insurance status, and medical comorbidities. After adjusting for these covariates, pregnant people were significantly more likely to accept influenza vaccine in the COVID cohort (adjusted odds ratio [aOR] 1.7, 95% confidence interval [CI] 1.27-2.29) and had similar Tdap acceptance (aOR 1.5, 95% CI 0.99-2.17). However, this trend was not observed for the entire obstetric population; public insurance status and medical comorbidities were associated with lower vaccine rates during the pandemic. For those who had public insurance, rates of influenza vaccination decreased from 83% in 2019 to 40% during COVID (aOR 0.16, 95% CI 0.10-0.24) and for Tdap rates decreased from 93 to 54% (aOR 0.13, 95% CI 0.08-0.21).

CONCLUSION

 During the COVID-19 pandemic era, pregnant people at large were more likely to accept the influenza vaccine. However, this trend did not apply to Tdap, and high-risk groups with public insurance and medical comorbidities. This study highlights potential disparities in vaccination rates, which need to be accounted for when evaluating national vaccine trends. These data support increased efforts in vaccine counseling for high-risk populations.

KEY POINTS

· Antenatal flu vaccination increased during the pandemic.. · Antenatal Tdap vaccination was unchanged during the pandemic.. · High-risk pregnant patients had decreased vaccine uptake.. · High-risk subgroups were not included in overarching vaccination trends..

Can human papillomavirus vaccination during pregnancy result in miscarriage and stillbirth? A meta-analysis and systematic review

INTRODUCTION

Contradictory results regarding the safety of human papillomavirus (HPV) vaccination during pregnancy have been obtained, which has cast doubt on the use of this method. This review and meta-analysis were conducted to evaluate the safety of HPV vaccination during pregnancy.

METHODS

Complying with the inclusion and exclusion criteria, we searched Web of Science, Scopus, Medline, EMBASE, PubMed and Google Scholar databases for articles published in the past decade using the following keywords: 'papilloma human virus', 'HPV vaccine', 'pregnancy' and 'safety and prevention'. The minimum report quality of the articles was 16 based on the STROBE checklist.

RESULTS

Seven articles were included in the study, three of which were included in the meta-analysis, and the rest were reviewed systematically. The results of the meta-analysis showed that vaccination against HPV during pregnancy or around this period does not increase the risk of miscarriage (RR=2.01; 95% CI: 0.66-6.13) and stillbirth (RR=2.02: 95% CI: 0.65-6.27). No significant difference between miscarriage and stillbirth was observed in women vaccinated against HPV versus those not vaccinated.

CONCLUSIONS

The study of 1380424 individuals showed that HPV vaccination during pregnancy is better postponed until after this period. However, no significant evidence was found to indicate that vaccination was dangerous and unsafe during pregnancy. Further studies are needed to draw a more definitive conclusion.

Safety and protective capability of an inactivated SARS-CoV-2 vaccine on pregnancy, lactation and the growth of offspring in hACE2 mice

The mass inoculation of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine to induce herd immunity is one of the most effective measures to fight COVID-19. The vaccination of pregnant women cannot only avoid or reduce the probability of infectious diseases, but also offers the most effective and direct protection for neonates by means of passive immunization. However, there is no randomized clinical data to ascertain whether the inactivated vaccination of pregnant women or women of childbearing age can affect conception and the fetus. We found that human angiotensin-converting enzyme 2 (hACE2) mice that were vaccinated with two doses of CoronaVac (an inactivated SARS-CoV-2 vaccine) before and during pregnancy exhibited normal weight changes and reproductive performance indices; the physical development of their offspring was also normal. Following intranasal inoculation with SARS-CoV-2, pregnant mice in the immunization group all survived; reproductive performance indices and the physical development of offspring were all normal. In contrast, mice in the non-immunization group all died before delivery. Analyses showed that inoculation of CoronaVac was safe and did not exert any significant effects on pregnancy, lactation, or the growth of offspring in hACE2 mice. Vaccination effectively protected the pregnant mice against SARS-CoV-2 infection and had no adverse effects on the growth and development of the offspring, thus suggesting that inoculation with an inactivated SARS-CoV-2 vaccine may be an effective strategy to prevent infection in pregnant women.

Functional and structural modifications of influenza antibodies during pregnancy

Pregnancy represents a unique tolerogenic immune state which may alter susceptibility to infection and vaccine response. Here, we characterized humoral immunity to seasonal influenza vaccine strains in pregnant and non-pregnant women. Although serological responses to influenza remained largely intact during late pregnancy, distinct modifications were observed. Pregnant women had reduced hemagglutinin subtype-1 (H1)- IgG, IgG1, IgG2, and IgG3, hemagglutination inhibition, and group 1 and 2 stem IgG titers. Intriguingly, H1-specific avidity and FcγR1 binding increased, and influenza antibodies had distinct Fc and Fab glycans characterized by increased di-galactosylation and di-sialylation. H1-specific Fc-functionality (i.e. monocyte phagocytosis and complement deposition) was moderately reduced in pregnancy. Multivariate antibody analysis revealed two distinct populations (pregnant vs. non-pregnant) segregated by H1 FcγR1 binding, H1-IgG levels, and Fab and Fc glycosylation. Our results demonstrated a structural and functional modulation of influenza humoral immunity during pregnancy that was antigen-specific and consistent with reduced inflammation and efficient placental transport.

Attitude for vaccination prophylaxis among pregnant women: a cross-sectional study

Pregnant women and newborns are considered a subgroup of population at increased risk for several infectious diseases, some of which are vaccine-preventable. Anti-diphtheria-tetanus-pertussis vaccine (dTpa) and influenza vaccine are recommended for pregnant women. We carried out a study to evaluate the knowledge of new mothers toward the main vaccine-preventable diseases and to assess their compliance with recommended vaccinations. Using the Hospital Discharge Forms (SDO), the list of women who gave birth in 2018 was generated. Women were interviewed by a questionnaire administered by telephone. The study sample consisted of 145 subjects, with an average age of 35.0 ± 5.9 years (range = 18.0–47.0). 5/145 (3.4%; 95% CI = 1.1–7.9%) subjects were advised during pregnancy to have the flu shot; only 1/145 (0.7%; 95% CI = 0.5–71.6%) reported the flu vaccine during the last pregnancy. 94/145 (64.8%; 95% CI = 57.2–73.2%) respondents declared that they had carried out the TORCH panel exams before pregnancy; of these 18/94 (19.2%; 95% C = 11.8–28.6%) were susceptible for rubella. Of these subjects, for 7/18 (38.9%; 95% CI = 17.3–64.3%) rubella vaccination was offered and 5/7 (71.4%; 95% CI = 29.0–96.3%) decided to carry out the vaccination. Only 1/145 (0.7%; 95% CI = 0.0–3.8%) of the interviewed woman underwent anti-dTap vaccination. Greater efforts must be made by public health institutions to raise awareness and improve vaccination compliance in this population.

The Current Evidence Regarding COVID-19 and Pregnancy: Where Are We Now and Where Should We Head to Next?

Despite the volume of publications dedicated to unraveling the biological characteristics and clinical manifestations of SARS-CoV-2, available data on pregnant patients are limited. In the current review of literature, we present an overview on the developmental course, complications, and adverse effects of COVID-19 on pregnancy. A comprehensive review of the literature was performed in PubMed/Medline, Embase, and Cochrane Central databases up to June 2021. This article collectively presents what has been so far reported on the identified critical aspects, namely complications during pregnancy, delivery challenges, neonatal health care, potential routes of viral transmission, including vertical transmission or breastfeeding, along with the risks involved in the vaccination strategy during pregnancy. Despite the fact that we are still largely navigating uncharted territory, the observed publication explosion in the field is unprecedented. The overwhelming need for data is undoubtable, and this serves as the driver for the plethora of publications witnessed. Nonetheless, the quality of data sourced is variable. In the midst of the frenzy for reporting on SARS-CoV-2 data, monitoring this informational overload is where we should head to next, considering that poor quality research may in fact hamper our attempts to prevail against this unparalleled pandemic outbreak.

COVID-19 vaccination in pregnant and lactating diabetic women

AIM

To discuss available information on the opportunity for pregnant women affected by diabetes/obesity to receive COVID-19 vaccine.

DATA SYNTHESIS

Pregnant women with SARS-CoV-2 (COVID-19) infection are at high risk for severe acute respiratory syndrome and adverse outcomes. Pregnant women with severe COVID-19 present increased rates of preterm delivery (<37 gestational weeks), cesarean delivery and neonatal admissions to the intensive care unit. Comorbidity such as diabetes (pregestational or gestational) or obesity further increased maternal and fetal complications. It is known that diabetic or obese patients with COVID-19 present an unfavorable course and a worse prognosis, with a direct association between worse outcome and suboptimal glycol-metabolic control or body mass index (BMI) levels. Critical COVID-19 infection prevention is important for both mother and fetus. Vaccination during pregnancy is a common practice. Vaccines against COVID-19 are distributed across the world with some population considered to have a priority. Since pregnant women are excluded from clinical trials very little information are available on safety and efficacy of COVD-19 vaccines during pregnancy. However, it is well known the concept of passive immunization of the newborn obtained with transplacental passage of protective antibodies into the fetal/neonatal circulation after maternal infection or vaccination. Moreover, it has been reported that COVID-19 vaccine-induced IgG pass to the neonates through breastmilk. Therefore, maternal vaccination can protect mother, fetus and baby.

CONCLUSIONS

After an individual risk/benefit evaluation pregnant and lactating women should be counselled to receive COVID-19 vaccines.

Factors associated with births protected against neonatal tetanus in Africa: Evidences from Demographic and health surveys of five African countries

INTRODUCTION

Maternal and neonatal tetanus remains a global public health problem affecting mainly the poorest and most marginalized subpopulations. In spite of the problem, studies conducted on the associated factors of births protected against neonatal tetanus are scarce in Africa. Therefore, this study aimed to identify both individual and community-level factors associated with births protected against neonatal tetanus in the region.

METHODS

The most recent Demographic and Health Survey datasets of five African countries (Ethiopia, Burundi, Comoros, Zimbabwe and Zambia) were used to investigate the associated factors of births protected from neonatal tetanus. STATA Version 14 statistical software was used for the analysis. The data were weighted before doing any statistical analysis and deviance was used for model comparison. Multilevel binary logistic regression was used to identify the associated factors of births protected against neonatal tetanus. Finally, the adjusted odds ratio (AOR) with its 95% confidence interval (CI) was calculated for each potential factors included in the multivariable multilevel logistic regression model.

RESULTS

A total weighted sample of 30897 reproductive age women who had a birth within 5 years preceding the survey were included in the analysis. Those women with age of 20-34 (AOR = 1.32, 95%CI: 1.18-1.48) and 35-49 years (AOR = 1.26, 95% CI: 1.10-1.44), high community level of women education (AOR = 1.13, 95%CI: 1.04-1.23), being from poorer(AOR = 1.23, 95% CI: 1.14-1.33), middle (AOR = 1.31, 95%CI: 1.21-1.43), richer (AOR = 1.21, 95%CI: 1.11-1.32) and richest households (AOR = 1.59, 95%CI: 1.44-1.74), having antenatal care follow up (AOR = 9.62, 95% CI: 8.79-10.54), not perceiving distance to health facility as a big problem (AOR = 1.18, 95% CI: (1.11-1.25) had higher odds of having births protected against neonatal tetanus.

CONCLUSION

Both individual and community level factors were found to be associated with births protected against neonatal tetanus in Africa. This suggests that a variety of factors are affecting births protected against neonatal tetanus in the region. Hence, the impact of these factors should be recognized while developing strategies to reduce neonatal tetanus in the region.

Methodologic approaches in studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women: A scoping review

OBJECTIVE

This scoping review mapped studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women.

INTRODUCTION

In the US, two vaccines are recommended for all pregnant women to prevent illness in the infant: inactivated influenza vaccine (recommended since 2004), and the combined tetanus-diphtheria-acellular pertussis (Tdap) vaccine (recommended since 2013). This scoping review maps the studies conducted to date that address questions about pediatric safety and effectiveness of vaccines administered during pregnancy and provides a knowledge base for evaluating the use of RWD to study this issue.

METHODS

The scoping review was conducted following a published protocol. Methods included an electronic search of PubMed and Embase, screening of titles and abstracts by two reviewers, and double extraction of data for summary and synthesis. Studies that reported on pregnant women and the effectiveness or safety outcomes in their infants were included.

RESULTS

Forty-eight studies met the inclusion criteria of the scoping review protocol using RWD to assess safety or effectiveness of influenza or pertussis vaccinations administered to pregnant women with respect to pregnancy, infant or child outcomes. Detailed information about data sources, linkage of maternal and infant data, and operational definitions for gestational age were largely absent from the majority of studies raising concerns about reproducibility and validity of study findings.

CONCLUSIONS

A body of literature is available from which to plan and design future studies of vaccination in pregnant women using RWD. This is of intense importance as new vaccines, such as those for COVID-19, become available to the general population via approval or authorization without inclusion of pregnant women in the clinical trials.

Methodologic approaches in studies using real-world data to measure pediatric safety and effectiveness of vaccines administered to pregnant women: a scoping review protocol

OBJECTIVE

This scoping review aims to map studies using real-world data (RWD) to measure pediatric safety and effectiveness of vaccines administered to pregnant women.

INTRODUCTION

In the United States, two vaccines are recommended for all pregnant women to prevent illness in the infant: inactivated influenza vaccine (recommended since 2004) and the combined tetanus-diphtheria-acellular pertussis (Tdap) vaccine (recommended since 2013). Because of the ethical constraints in conducting randomized clinical trials to measure the effects on the infant, there is great interest in using electronic health care data or administrative claims data to study the effects of maternal immunization on the infant's health, and it is anticipated that such studies may be submitted to support regulatory decision-making. This scoping review will map the studies conducted to date that address these questions and provide a context for considering the regulatory issues that may arise in the future.

INCLUSION CRITERIA

Studies that report on pregnant women receiving immunization and the effectiveness or safety outcomes in their infants will be included. Study participants may be from any population or country, of any reproductive age, and with any health status. Studies will be included if they use real-world data (from electronic health records, administrative claims, pharmacy benefit records, or registries).

METHODS

An electronic search of PubMed and Embase will identify citations for screening. The search will be limited to studies published in English during the preceding 10 years. Two reviewers will screen citations in a two-step process (titles and abstracts, then full-text articles), and two reviewers will extract data for summary and synthesis.

Barriers and Facilitators Associated With Vaccine Acceptance and Uptake Among Pregnant Women in High Income Countries: A Mini-Review

Vaccination during pregnancy is a safe and effective intervention to protect women from potentially severe consequences of influenza and reduce risk of influenza and pertussis in their infants. However, coverage remains variable. In this mini-review we update findings from a 2015 systematic review to describe results from recent studies in high income countries on the uptake of influenza and pertussis vaccination in pregnancy, reasons for vaccine hesitancy and barriers to increasing uptake, from maternal and healthcare provider (HCP) perspectives. Studies reported highly variable uptake (from 0% to 78%). A main facilitator for uptake among pregnant women was receiving a recommendation from their HCP. However, studies showed that HCP awareness of guidelines did not consistently translate into them recommending vaccines to pregnant women. Safety concerns are a well-established barrier to uptake/coverage of maternal immunization; 7%-52% of unvaccinated women gave safety concerns as a reason but these were also present in vaccinated women. Knowledge/awareness gaps among pregnant women and lack of confidence among HCPs to discuss vaccination were both important barriers. Several studies indicated that midwives were more likely to express safety concerns than other HCPs, and less likely to recommend vaccination to pregnant women. Women who perceived the risk of infection to be low were less likely to accept vaccination in several studies, along with women with prior vaccine refusal. Findings highlight the importance of further research to explore context-specific barriers to vaccination in pregnancy, which may include lack of vaccine confidence among pregnant woman and HCPs, and policy and structural factors.

Coronavirus Disease 2019 (COVID-19) Vaccines and Pregnancy: What Obstetricians Need to Know

Obstetricians will need to use the limited available data to guide their pregnant patients regarding benefits and risks of coronavirus disease 2019 (COVID-19) vaccination.

Coronavirus disease 2019 (COVID-19) vaccines have begun to be distributed across the United States and to be offered initially to priority groups including health care personnel and persons living in long-term care facilities. Guidance regarding whether pregnant persons should receive a COVID-19 vaccine is needed. Because pregnant persons were excluded from the initial phase 3 clinical trials of COVID-19 vaccines, limited data are available on their efficacy and safety during pregnancy. After developmental and reproductive toxicology studies are completed, some companies are expected to conduct clinical trials in pregnant persons. Until then, pregnant persons and their obstetricians will need to use available data to weigh the benefits and risks of COVID-19 vaccines. Issues to be considered when counseling pregnant persons include data from animal studies and inadvertently exposed pregnancies during vaccine clinical trials when available, potential risks to pregnancy of vaccine reactogenicity, timing of vaccination during pregnancy, evidence for safety of other vaccines during pregnancy, risk of COVID-19 complications due to pregnancy and the pregnant person's underlying conditions, and risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential for risk mitigation. The Centers for Disease Control and Prevention, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine have each issued guidance supportive of offering COVID-19 vaccine to pregnant persons. As additional information from clinical trials and from data collected on vaccinated pregnant persons becomes available, it will be critical for obstetricians to keep up to date with this information.

Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

Updates on Vaccine Safety and Post-Licensure Surveillance for Adverse Events Following Immunization in South Korea, 2005-2017

PURPOSE

Vaccine hesitancy is among the top ten threats to global health, and access to precise data on adverse events following immunization (AEFIs) is imperative to alleviate public concerns surrounding vaccines. This study aimed to present the overall trends of AEFIs reported in South Korea.

MATERIALS AND METHODS

We evaluated the trends of AEFIs using the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System database between January 2005 and December 2017. AEFIs were classified into five categories to evaluate associations between vaccines and AEFIs through a case-non-case study: neurologic reactions, general systemic reactions, local reactions, allergic reactions, and others.

RESULTS

Among 54378 reported adverse events (AEs) associated with all vaccines approved in South Korea, more than half (56.7%) occurred following influenza vaccination, followed by the pneumococcal (11.6%) and Bacillus Calmette-Guérin (BCG) vaccines (5.0%). After immunization with most vaccines, general systemic reactions were most common, followed by local and neurologic reactions. Adjusted reporting odds ratios were calculated for all neurologic, general, local, and allergic reactions: of all vaccines, rotavirus [neurologic 2.43, 95% confidence interval (CI), 2.25-2.62], BCG (general; 2.20, 95% CI, 1.91-2.53), BCG (local; 3.15, 95% CI, 2.69-3.68), and Japanese encephalitis (allergic 2.38, 95% CI, 1.98-2.87) vaccines showed the highest values.

CONCLUSION

The majority of reported AEFIs were non-serious and mostly general systemic reactions. Sufficient knowledge on the AEFIs would secure public confidence on the safety of vaccines, thereby reducing public health burden from vaccine-preventable diseases.

Pregnancy outcomes after a mass vaccination campaign with an oral cholera vaccine: a systematic review and meta-analysis

BACKGROUND

Cholera has harmful effects on the fetus but safety data on the oral cholera vaccine in pregnant women are controversial.

OBJECTIVES

We conducted the first meta-analysis of studies in pregnant women comparing the effect of oral cholera vaccination on pregnancy outcomes with unvaccinated women. Outcomes of interest were adverse pregnancy outcome, miscarriage, stillbirth, preterm delivery, low birthweight, abortion and malformation.

SEARCH STRATEGY

The search was run in MEDLINE/PubMed, SCOPUS and Embase databases from inception up to December 2019.

SELECTION CRITERIA

Inclusion criteria were: (1) studies that investigated the association between oral cholera vaccines and adverse pregnancy outcomes; (2) studies that reported outcomes with appropriate estimates; and (3) studies that contained an unvaccinated control group.

DATA COLLECTION AND ANALYSIS

A random-effects model (DerSimonian and Laird) was run to evaluate the overall treatment effect (relative risk, RR). The PRISMA statement was followed in reporting this meta-analysis.

MAIN RESULTS

Five studies included in meta-analysis with 5584 women (2920 exposed and 2664 not exposed). No significant increase in adverse pregnancy outcome (RR 1.03, 95% CI 0.79-1.34), miscarriage (RR 1.15, 95% CI 0.84-1.57) or stillbirth (RR 1.11, 95% CI 0.69-1.80) following cholera vaccine administration was found compared with control group. There was also no association with an increased risk of preterm delivery (RR 0.61, 95% CI 0.35-1.06) low birthweight (RR 0.84, 95% CI 0.56- 1.26), accidental abortion (RR 1.02, 95% CI 0.77-1.35) or malformation (RR 0.70, 95% CI 0.22-2.25).

CONCLUSIONS

This study shows no evidence of an association between oral cholera vaccination and adverse pregnancy outcomes. The findings do not rigorously exclude the possibility that the vaccine protocol may result in some degree of harm.

TWEETABLE ABSTRACT

There is no evidence of an association between oral cholera vaccination and adverse pregnancy outcomes. The findings do not rigorously exclude the possibility that the vaccine protocol may result in some degree of harm.

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

BACKGROUND

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

OBJECTIVES

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

RESULTS

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

CONCLUSIONS

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

Immunogenicity and Safety of 3 Formulations of a Respiratory Syncytial Virus Candidate Vaccine in Nonpregnant Women: A Phase 2, Randomized Trial

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of respiratory tract illness and hospitalization in neonates and infants. RSV vaccination during pregnancy may protect offspring in their first months of life.

METHODS

This randomized, observer-blind, multicenter, phase 2 study evaluated the immunogenicity and safety of an RSV candidate vaccine in healthy nonpregnant women aged 18-45 years. Four hundred participants were randomized (1:1:1:1) to receive a single intramuscular dose of vaccine containing 30 µg, 60 µg, or 120 µg of RSV fusion protein engineered to preferentially maintain a prefusion conformation (RSV-PreF vaccine) or placebo.

RESULTS

Thirty days postvaccination, RSV-A neutralizing antibody geometric mean titers (GMTs) increased 3.75-, 4.42- and 4.36-fold; RSV-B neutralizing antibody GMTs 2.36-, 2.54- and 2.76-fold; and palivizumab competing antibody (PCA) concentrations 11.69-, 14.38- and 14.24-fold compared with baseline levels in the 30 µg, 60 µg, and 120 µg RSV-PreF groups, respectively. Antibody titers and PCA concentrations at day 30 were significantly higher with the 120 µg compared to the 30 µg RSV-PreF vaccine. All RSV-PreF vaccine formulations and the placebo had similar reactogenicity profiles. No serious adverse events were considered to be related to the RSV-PreF vaccine.

CONCLUSIONS

The 3 formulations of the investigational RSV-PreF vaccine were well-tolerated and induced RSV-A and RSV-B neutralizing antibodies and PCAs in healthy, nonpregnant women.

CLINICAL TRIALS REGISTRATION

NCT02956837.

Effects of maternal influenza vaccination on adverse birth outcomes: A systematic review and Bayesian meta-analysis

BACKGROUND

Although pregnant women are a priority group for influenza vaccination, its effect on birth outcomes has long been debated. Numerous observational studies and a few randomized controlled studies have been conducted, with inconsistent results.

OBJECTIVES

To evaluate the association of influenza vaccination in pregnancy with adverse birth outcomes.

DATA SOURCE

The Cochrane Library, PubMed, EMBASE, Web of Science, and Scopus were searched.

STUDY ELIGIBILITY CRITERIA

This analysis included randomized placebo-controlled studies, cohort studies, and case-control studies, in which inactivated influenza vaccination was given during pregnancy and fetal adverse birth outcomes were assessed.

PARTICIPANTS & INTERVENTION

Women who received inactivated influenza vaccine during pregnancy and their offspring.

STUDY APPRAISAL AND SYNTHESIS

Two independent reviewers and a third reviewer collaborated in study selection and data extraction. A Bayesian 3-level random-effects model was utilized to assess the impact of maternal influenza vaccination on birth outcomes, which were presented as odds ratios (ORs) with 95% credible interval (CrIs). Bayesian outcome probabilities (P) of an OR<1 were calculated, and values of at least 90% (0.9) were deemed to indicate a significant result.

RESULTS

Among the 6,249 identified publications, 48 studies were eligible for the meta-analysis, including 2 randomized controlled trials, 41 cohort studies, and 5 case-control studies. The risk of none of the following adverse birth outcomes decreased significantly: preterm birth (OR = 0.945, 95% CrI: 0.736-1.345, P = 73.3%), low birth weight (OR = 0.928, 95% CrI: 0.432-2.112, P = 76.7%), small for gestational age (OR = 0.971, 95% CrI: 0.249-4.217,P = 63.3%), congenital malformation (OR = 1.026, 95% CrI: 0.687-1.600, P = 38.0%), and fetal death (OR = 0.942, 95% CrI: 0.560-1.954, P = 61.6%). Summary estimates including only cohort studies showed significantly decreased risks for preterm birth, small for gestational age and fetal death. However, after adjusting for season at the time of vaccination and countries' income level, only fetal death remained significant.

CONCLUSION

This Bayesian meta-analysis did not find a protective effect of maternal influenza vaccination against adverse birth outcomes, as reported in previous studies. In fact, our results showed evidence of null associations between maternal influenza vaccination and adverse birth outcomes.

Safety, equity and monitoring: a review of the gaps in maternal vaccination strategies for Aboriginal and Torres Strait Islander women

Influenza and pertussis infections are disproportionately higher among Aboriginal and Torres Strait Islander women and their infants compared to other Australians. These infections are potentially preventable through vaccination in pregnancy; however, there is a lack of systematic monitoring and therefore knowledge of vaccine uptake, safety and effectiveness in Australia, and specifically among Aboriginal and Torres Strait Islander women. The limited data available suggest there is a lower uptake of maternal vaccination among Aboriginal and Torres Strait Islander women compared to non-Aboriginal and Torres Strait Islander women, and this review seeks to explore potential reasons and the knowledge gaps in this regard. Other key gaps include the equitable access to quality antenatal care for Aboriginal and Torres Strait Islander women; and pregnancy loss <20 weeks gestation. Furthermore, our review highlights the importance of addressing these gaps in maternal vaccination strategies in partnership with Aboriginal and Torres Strait Islander peoples.

Why Should We Advocate Maternal Immunization?

Maternal vaccination provides a method for protecting the pregnant woman, fetus and neonate during a period when there is increased susceptibility to infectious diseases. A dynamic state of immune tolerance during pregnancy and the need to develop adaptive memory to a new foreign antigen-rich environment lead to windows of vulnerability to infection for the mother and neonate, respectively. Passive transfer of humoral immunity through the placenta and breast milk from the mother can bridge the gap in immunity for the neonate. Studies on boosting this natural process of antibody transfer have led to the recommendation for administering inactivated influenza, diphtheria, tetanus toxoid and acellular pertussis vaccines during pregnancy. Several new maternal vaccine candidates are on the horizon.

Factors influencing refusing of flu vaccination among pregnant women in Italy: Healthcare workers' role

BACKGROUND

Pregnant women are at increased risk of influenza complications. Influenza vaccine provides them a substantial protection.

OBJECTIVE

The aim of this study was to investigate determinants associated with non-adherence to influenza vaccine recommendations in pregnant women in Italy.

METHODS

A cross-sectional study has been carried out among pregnant women attending their follow-up visit in some mother and child services in a Region of Italy from October 2016 to January 2017. The study protocol was approved by the local research Ethics. A self-administered close-ended questionnaire has been administered to the pregnant women. Differences in background, socio-demographic characteristics, knowledge and attitudes towards flu vaccine were tested in vaccinated and unvaccinated women. Multivariate analysis was performed to control for confounding factors.

RESULTS

Three hundred and sixty-six women answered the survey (97% response rate) and 96.1% (348) declared of being unvaccinated against influenza during the 2016-2017 influenza season. Frequent reasons for refusing vaccination were drugs objection and concerns about vaccines' effects. According to the refusal attitude, influenza knowledge was low in the group. Moreover, analysis showed that low adherence to vaccination is associated to lacking promotion of vaccination to pregnant women carried out by healthcare workers (P < 0.005).

CONCLUSIONS

Healthcare workers have a key role in assisting women during the gestational period, so their active involvement in vaccination promotion is essential. It is necessary to improve health care workers' knowledge about vaccine relevance in protecting pregnancy and their communication skills to properly inform pregnant women.

A Functionally Different Immune Phenotype in Cattle Is Associated With Higher Mastitis Incidence

A novel vaccine against bovine viral diarrhea (BVD) induced pathogenic antibody production in 5-10% of BVD-vaccinated cows. Transfer of these antibodies via colostrum caused Bovine neonatal pancytopenia (BNP) in calves, with a lethality rate of 90%. The exact immunological mechanisms behind the onset of BNP are not fully understood to date. To gain further insight into these mechanisms, we analyzed the immune proteome from alloreactive antibody producers (BNP cows) and non-responders. After in vitro stimulation of peripheral blood derived lymphocytes (PBL), we detected distinctly deviant expression levels of several master regulators of immune responses in BNP cells, pointing to a changed immune phenotype with severe dysregulation of immune response in BNP cows. Interestingly, we also found this response pattern in 22% of non-BVD-vaccinated cows, indicating a genetic predisposition of this immune deviant (ID) phenotype in cattle. We additionally analyzed the functional correlation of the ID phenotype with 10 health parameters and 6 diseases in a retrospective study over 38 months. The significantly increased prevalence of mastitis among ID cows emphasizes the clinical relevance of this deviant immune response and its potential impact on the ability to fight infections.

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

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

Practice and attitudes towards immunization among Lebanese obstetricians and gynecologists

We designed our study to evaluate the knowledge and immunization practices among Lebanese obstetricians and gynecologists (OBGYN) for women of different age groups. Anonymous questionnaires were used to assess the knowledge and immunization practices among OBGYN. The survey was conducted at the annual meeting of the Lebanese Society of Obstetrics and Gynecology on November 13-15, 2014. Data collected included demographics, type of practice, academic background and familiarity with vaccine guidelines. Descriptive statistical methods were used to evaluate the responses. The response rate was 54.8% (114/208). Only 62.3% (71/114) recommend vaccination(s) to pregnant women with only 25.9% of those who recommend the Tdap vaccine for pregnant women giving it during the recommended third trimester. In addition, 52.6% are unaware of the CDC/ACIP immunization schedule for women in general. However, 83.0% (93/112) of respondents are willing to integrate vaccination in their practice. Our study highlights several gaps in the knowledge of Lebanese OBGYN regarding vaccination in addition to practices that are not in full accordance with common guidelines. Measures should be taken to spread proper awareness of the proper guidelines among Lebanese practitioners.

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

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

Impact of pregnancy on observed sex disparities among adults hospitalized with laboratory-confirmed influenza, FluSurv-NET, 2010-2012

INTRODUCTION

Previous FluSurv-NET studies found that adult females had a higher incidence of influenza-associated hospitalizations than males. To identify groups of women at higher risk than men, we analyzed data from 14 FluSurv-NET sites that conducted population-based surveillance for laboratory-confirmed influenza-associated hospitalizations among residents of 78 US counties.

METHODS

We analyzed 6292 laboratory-confirmed, geocodable (96%) adult cases collected by FluSurv-NET during the 2010-12 influenza seasons. We used 2010 US Census and 2008-2012 American Community Survey data to calculate overall age-adjusted and age group-specific female:male incidence rate ratios (IRR) by race/ethnicity and census tract-level poverty. We used national 2010 pregnancy rates to estimate denominators for pregnant women aged 18-49. We calculated male:female IRRs excluding them and IRRs for pregnant:non-pregnant women.

RESULTS

Overall, 55% of laboratory-confirmed influenza cases were female. Female:male IRRs were highest for females aged 18-49 of high neighborhood poverty (IRR 1.50, 95% CI 1.30-1.74) and of Hispanic ethnicity (IRR 1.70, 95% CI 1.34-2.17). These differences disappeared after excluding pregnant women. Overall, 26% of 1083 hospitalized females aged 18-49 were pregnant. Pregnant adult females were more likely to have influenza-associated hospitalizations than their non-pregnant counterparts (relative risk [RR] 5.86, 95% CI 5.12-6.71), but vaccination levels were similar (25.5% vs 27.8%).

CONCLUSIONS

Overall rates of influenza-associated hospitalization were not significantly different for men and women after excluding pregnant women. Among women aged 18-49, pregnancy increased the risk of influenza-associated hospitalization sixfold but did not increase the likelihood of vaccination. Improving vaccination rates in pregnant women should be an influenza vaccination priority.

Forecasting Epidemiological Consequences of Maternal Immunization

BACKGROUND

 The increase in the incidence of whooping cough (pertussis) in many countries with high vaccination coverage is alarming. Maternal pertussis immunization has been proposed as an effective means of protecting newborns during the interval between birth and the first routine dose. However, there are concerns regarding potential interference between maternal antibodies and the immune response elicited by the routine schedule, with possible long-term population-level effects.

METHODS

 We formulated a transmission model comprising both primary routine and maternal immunization. This model was examined to evaluate the long-term epidemiological effects of routine and maternal immunization, together with consequences of potential immune interference scenarios.

RESULTS

 Overall, our model demonstrates that maternal immunization is an effective strategy in reducing the incidence of pertussis in neonates prior to the onset of the primary schedule. However, if maternal antibodies lead to blunting, incidence increases among older age groups. For instance, our model predicts that with 60% routine and maternal immunization coverage and 30% blunting, the incidence among neonates (0-2 months) is reduced by 43%. Under the same scenario, we observe a 20% increase in incidence among children aged 5-10 years. However, the downstream increase in the older age groups occurs with a delay of approximately a decade or more.

CONCLUSIONS

 Maternal immunization has clear positive effects on infant burden of disease, lowering mean infant incidence. However, if maternally derived antibodies adversely affect the immunogenicity of the routine schedule, we predict eventual population-level repercussions that may lead to an overall increase in incidence in older age groups.

Assessing the Evidence for Maternal Pertussis Immunization: A Report From the Bill & Melinda Gates Foundation Symposium on Pertussis Infant Disease Burden in Low- and Lower-Middle-Income Countries

Implementation of effective interventions has halved maternal and child mortality over the past 2 decades, but less progress has been made in reducing neonatal mortality. Almost 45% of under-5 global mortality now occurs in infants <1 month of age, with approximately 86% of neonatal deaths occurring in low- and lower-middle-income countries (LMICs). As an estimated 23% of neonatal deaths globally are due to infectious causes, maternal immunization (MI) is one intervention that may reduce mortality in the first few months of life, when direct protection often relies on passively transmitted maternal antibodies. Despite all countries including pertussis-containing vaccines in their routine childhood immunization schedules, supported through the Expanded Programme on Immunization, pertussis continues to circulate globally. Although based on limited robust epidemiologic data, current estimates derived from modeling implicate pertussis in 1% of under-5 mortality, with infants too young to be vaccinated at highest risk of death. Pertussis MI programs have proven effective in reducing infant pertussis mortality in high-income countries using tetanus-diphtheria-acellular pertussis (Tdap) vaccines in their maternal and infant programs; however, these vaccines are cost-prohibitive for routine use in LMICs. The reach of antenatal care programs to deliver maternal pertussis vaccines, particularly with respect to infants at greatest risk of pertussis, needs to be further evaluated. Recognizing that decisions on the potential impact of pertussis MI in LMICs need, as a first step, robust contemporary mortality data for early infant pertussis, a symposium of global key experts was held. The symposium reviewed current evidence and identified knowledge gaps with respect to the infant pertussis disease burden in LMICs, and discussed proposed strategies to assess the potential impact of pertussis MI.

The risks of using allogeneic cell lines for vaccine production: the example of Bovine Neonatal Pancytopenia

INTRODUCTION

Bovine neonatal pancytopenia (BNP) is a hemorrhagic disease that emerged in calves across Europe in 2007. Its occurrence is attributed to immunization of the calf's mother with a vaccine produced using an allogeneic cell line. Vaccine-induced alloantibodies specific for major-histocompatibility class I antigens are transferred from the mother to the calf via colostrum, leading to profound depletion of peripheral blood and bone marrow cells that is often fatal. Areas covered: Pubmed and Web of Science were used to search for literature relevant to BNP and the use of allogeneic vaccine cell lines. Following a review of the pathology and pathogenesis of this novel condition, we discuss potential risks associated with the use of allogeneic vaccine cell lines. Expert commentary: Although BNP is associated with a specific vaccine, it highlights safety concerns common to all vaccines produced using allogeneic cell lines. Measures to prevent similar vaccine-induced alloimmune-mediated adverse events in the future are discussed.

Knowledge and attitude of pregnant women toward flu vaccination: a cross-sectional survey

OBJECTIVE

The study was conducted to explore the knowledge of pregnant women about influenza, influenza vaccine during pregnancy and the attitudes regarding immunization.

METHODS

A questionnaire based on the model proposed by Yudin in 2009 was translated, adapted and administered to 309 pregnant women in the third trimester of pregnancy between October 1 and December 1, 2013 at San Giovanni Calibita Fatebenefratelli hospital of Rome (Italy).

RESULTS

Most of the interviewed women (68.9%) answered that influenza is highly contagious, 34.6% of them believed that pregnant women have the same risk of complications as non-pregnant women. Only 5.8% were aware that the vaccine is recommended for women in the second and third trimester of pregnancy and only 14.2% of women answered that the vaccine is safe during pregnancy. Only 3/309 women reported recommendation and offer of vaccination during current pregnancy, but none of them was vaccinated.

CONCLUSIONS

Overall, knowledge regarding influenza, implications during pregnancy and influenza vaccine was poor among pregnant women. In Italy, the National Vaccine Prevention Plan 2012-2014 recommends influenza vaccine during pregnancy, but only 18/309 were aware of this recommendation. These results suggest that in order to increase influenza vaccine acceptance it is necessary to improve pregnant women knowledge about influenza and to offer education to healthcare providers.

Occupational Health Update: Focus on Preventing the Acquisition of Infections with Pre-exposure Prophylaxis and Postexposure Prophylaxis

Health care personnel are commonly exposed to infectious agents via sharp injuries (eg, human immunodeficiency virus, hepatitis B virus, and hepatitis C virus), direct patient care (eg, pertussis and meningococcus), and the contaminated environment (eg, Clostridium difficile). An effective occupational program is a key aspect of preventing acquisition of an infection by offering the following: (1) education of health care personnel regarding proper handling of sharps, early identification and isolation of potentially infectious patients, and hand hygiene; (2) assuring immunity to vaccine-preventable diseases; and, (3) immediate availability of a medical evaluation after a nonprotected exposure to an infectious disease.

Dismantling the Taboo against Vaccines in Pregnancy

Vaccinating pregnant women in order to protect them, the fetus, and the child has become universal in no way at all. Prejudice in health professionals add to fears of women and their families. Both these feelings are not supported by even the smallest scientific data. Harmlessness for the mother and the child has been observed for seasonal, pandemic, or quadrivalent influenza, mono, combined polysaccharide or conjugated meningococcal or pneumococcal, tetanus toxoid, acellular pertussis, human papillomavirus, cholera, hepatitis A, Japanese encephalitis, rabies, anthrax, smallpox, yellow fever, mumps, measles and rubella combined, typhoid fever, inactivated or attenuated polio vaccines, and Bacillus Calmétte Guerin vaccines. Instead, the beneficial effects of influenza vaccine for the mother and the child as well as of pertussis vaccine for the child have been demonstrated. Obstetrician-gynecologists, general practitioners, and midwives must incorporate vaccination into their standard clinical care. Strong communication strategies effective at reducing parental vaccine hesitancy and approval of regulatory agencies for use of vaccines during pregnancy are needed. It must be clear that the lack of pre-licensure studies in pregnant women and, consequently, the lack of a statement about the use of the vaccine in pregnant women does not preclude its use in pregnancy.

Influenza Vaccination During Pregnancy: Influenza Seasons 2002-2012, Vaccine Safety Datalink

INTRODUCTION

Pregnant women are at risk for influenza-related complications and have been recommended for vaccination by the Advisory Committee on Immunization Practices (ACIP) since 1990. Annual rates of influenza coverage of pregnant women have been consistently low. The Vaccine Safety Datalink was used to assess influenza vaccine coverage over 10 consecutive years (2002-2012); assess patterns related to changes in ACIP recommendations; identify predictors of vaccination; and compare the results with those published by national U.S. surveys.

METHODS

Retrospective cohort study of 721,898 pregnancies conducted in 2014. Coverage rates were assessed for all pregnancies and for live births only. Multivariate regression analysis identified predictors associated with vaccination.

RESULTS

Coverage increased from 8.8% to 50.9% in 2002-2012. Seasonal coverage rates increased slowly following the 2004 ACIP influenza vaccine recommendation (to remove the first trimester restriction), but spiked significantly during the 2009 H1N1 influenza pandemic. Significant predictors of vaccination during pregnancy included older age; vaccination in a previous season; high-risk conditions in addition to pregnancy; pregnancy during either the 2004-2005 or 2009-2010 seasons; entering the influenza season after the first trimester of pregnancy; and a pregnancy with longer overlap with the influenza season (p<0.001 for each).

CONCLUSIONS

Influenza vaccination coverage among pregnant women increased between the 2002-2003 and 2011-2012 seasons, although it was still below the developmental Healthy People 2020 goal of 80%. The 2004 ACIP language change positively impacted first-trimester vaccination uptake. Vaccine Safety Datalink data estimates were consistent with U.S. estimates.

Pregnancy boosts vaccine-induced Bovine Neonatal Pancytopenia-associated alloantibodies

Although maternal vaccination is generally considered to be safe, the occurrence of Bovine Neonatal Pancytopenia (BNP) in cattle shows that maternal vaccination may pose a risk to the offspring. Pregsure BVD-induced maternal alloantibodies cause BNP in newborn calves. The occurrence of BNP years after last Pregsure BVD vaccination indicates that alloantibody levels may remain high in dams. Since pregnancy induces alloantibodies we hypothesized that pregnancy boosts the vaccine-induced alloantibody response. Alloantibody levels in Pregsure BVD-vaccinated dams increased from conception towards the end of gestation and declined after parturition. In parallel, BVDV-antibody levels remained constant, indicating that there is specific boosting of alloantibodies. Since the rise in alloantibodies coincides with pregnancy and other alloantigen sources were excluded, we concluded that fetal alloantigens expressed during pregnancy boost the alloimmune response in the dam. These results help explain why BNP cases occur even years after Pregsure BVD has been taken off the market.

Meeting the Challenges of Immunizing Adults

The overall burden of illness from diseases for which vaccines are available disproportionately falls on adults. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccine recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Vaccine use among U.S. adults is low. Although receipt of a provider (physician or other vaccinating healthcare provider) recommendation is a key predictor of vaccination, more often consumers report not receiving vaccine recommendations at healthcare provider visits. Although providers support the benefits of vaccination, they also report several barriers to vaccinating adults, including the cost of providing vaccination services, inadequate or inconsistent payment for vaccines and vaccine administration, and acute medical care taking precedence over preventive services. Despite these challenges, a number of strategies have been demonstrated to substantially improve adult vaccine coverage, including patient and provider reminders and standing orders for vaccination. Providers are encouraged to incorporate routine assessment of their adult patients' vaccination needs during all clinical encounters to ensure patients receive recommendations for needed vaccines and are either offered needed vaccines or referred for vaccination.

Enhancing Vaccine Safety Capacity Globally: A Lifecycle Perspective

Major vaccine safety controversies have arisen in several countries beginning in the last decades of 20th century. Such periodic vaccine safety controversies are unlikely to go away in the near future as more national immunization programs mature with near elimination of target vaccine-preventable diseases that result in relative greater prominence of adverse events following immunizations, both true reactions and temporally coincidental events. There are several ways in which vaccine safety capacity can be improved to potentially mitigate the impact of future vaccine safety controversies. This paper aims to take a "lifecycle" approach, examining some potential pre- and post-licensure opportunities to improve vaccine safety, in both developed (specifically U.S. and Europe) and low- and middle-income countries.

Enhancing vaccine safety capacity globally: A lifecycle perspective

Major vaccine safety controversies have arisen in several countries beginning in the last decades of 20th century. Such periodic vaccine safety controversies are unlikely to go away in the near future as more national immunization programs mature with near elimination of target vaccine-preventable diseases that result in relative greater prominence of adverse events following immunizations, both true reactions and temporally coincidental events. There are several ways in which vaccine safety capacity can be improved to potentially mitigate the impact of future vaccine safety controversies. This paper aims to take a "lifecycle" approach, examining some potential pre- and post-licensure opportunities to improve vaccine safety, in both developed (specifically U.S. and Europe) and low- and middle-income countries.

Group B Streptococcus vaccine: state of the art

Group B Streptococcus (GBS) is cause of neonatal invasive diseases as well as of severe infections in the elderly and immune-compromised patients. Despite significant advances in the prevention and treatment of neonatal disease, sepsis and meningitis caused by GBS still represent a significant public health care concern globally and additional prevention and therapeutic strategies against infection are highly desirable. The introduction of national recommended guidelines in several countries to screen pregnant women for GBS carriage and the use of antibiotics during delivery significantly reduced disease occurring within the first hours of life (early-onset disease), but it has had no effect on the late-onset diseases occurring after the first week and is not feasible in most countries. Availability of an effective vaccine against GBS would provide an effective means of controlling GBS disease. This review provides an overview of the burden of invasive disease caused by GBS in infants and adults, and highlights the strategies for the development of an effective vaccine against GBS infections.

Group B streptococcal infections in the newborn infant and the potential value of maternal vaccination

Group B Streptococcus (GBS) is a leading cause of neonatal bacterial infections in developed countries. Early-onset disease (EOD) occurs at day 0-6 and late-onset disease occurs at day 7-89. Currently, the prevention of EOD relies upon intrapartum antibiotic prophylaxis (IAP) given to women who are GBS positive at prenatal screening or women with risk factors for EOD. Although successfully implemented, IAP has not fully eradicated EOD, and incidence rates of late-onset disease remain unchanged. Furthermore, antibiotic resistance may result from widespread antibiotic use. New prophylactic strategies are therefore of critical importance. A vaccine active against GBS, administered during pregnancy and combined with targeted IAP, could overcome these problems and reduce the mortality and morbidity associated with invasive diseases.

Pregnancy and severe influenza infection in the 2013-2014 influenza season

OBJECTIVE

To describe the epidemiologic and clinical characteristics of critically ill pregnant and postpartum women with influenza infection reported in the 2013-2014 season.

METHODS

The California Department of Public Health conducts surveillance for patients with laboratory-confirmed influenza who die or require hospitalization in intensive care units. For this case series, we reviewed data on pregnant and postpartum (6 weeks or less from delivery) women reported in the 2013-2014 influenza season.

RESULTS

From September 29, 2013, through May 17, 2014, 17 pregnant women with severe influenza were reported. The median age was 29 years (range 17-44 years). Sixteen (94%) were in the second or third trimester. Fifteen (88%) patients were hospitalized, nine (53%) required mechanical ventilation, five (29%) required emergent cesarean delivery, and four (24%) died. Of 14 patients with available information, only two (14%) received influenza vaccination during pregnancy. Seven patients who tested positive by polymerase chain reaction also had rapid influenza diagnostic testing performed; only one (14%) had a positive rapid influenza diagnostic test results. Fifteen patients received antiviral treatment; four (27%) began treatment within 48 hours of symptom onset. One additional patient was 36 days postpartum and required intensive care unit admission and mechanical ventilation for influenza-associated acute respiratory distress syndrome.

CONCLUSION

Influenza remains a significant cause of morbidity and mortality in pregnant and postpartum women; in our series, a majority were not vaccinated. During the influenza season, pregnant women with suspected influenza should receive prompt empiric antiviral therapy, regardless of rapid influenza diagnostic test results or vaccination status.

LEVEL OF EVIDENCE

III.

Influenza vaccination during pregnancy: a systematic review of fetal death, spontaneous abortion, and congenital malformation safety outcomes

BACKGROUND

Pregnant women are considered the most important risk group for influenza vaccination. Despite this, the potential risk of harm from the vaccine on the fetus is a key factor in low uptake of the vaccine. This systematic review aimed to synthesize the best available evidence on the safety of influenza vaccination during pregnancy on fetal development.

METHODS AND FINDINGS

A search of the literature was undertaken from the inception of each database up to March 2014. Both observational and clinical trials were considered. Fetal outcomes were present in 19 observational studies, and 14 of those were primarily investigating the monovalent influenza A (H1N1) 2009 vaccine. There was significant methodological and clinical heterogeneity of the included studies and a narrative summary and tabling of results was performed. Fetal death outcomes for women in later pregnancy ranged from OR 0.34 to 2.95 with 95% confidence intervals crossing or below the null value. Spontaneous abortion less than 24 weeks ranged from HR 0.45 to OR 1.23, with 95% confidence intervals crossing or below the null value. Congenital malformations for women vaccinated during their first trimester ranged from OR 0.67 to 2.18 and imprecise confidence intervals crossed the null value. Included in this review were some high quality studies, although overall the studies have a high risk of selection and confounding bias.

CONCLUSIONS

Results do not indicate that maternal influenza vaccination is associated with an increased risk of fetal death, spontaneous abortion, or congenital malformations. Statistical imprecision and clinical and methodological heterogeneity of the observational studies mean it is not possible to totally exclude adverse effects. Further studies investigating women vaccinated during their first trimester should be the highest priority to allow for more precise estimates, especially for spontaneous abortion, and congenital abnormality outcomes.