Effects of influenza on pregnant women and infants

Knowledge, attitudes, and perceptions of influenza vaccine among pregnant women in Minhang District, Shanghai

This study aimed to assess the attitudes and willingness of pregnant women to receive the influenza vaccine and the factors influencing their decisions. A sample survey was conducted among pregnant women receiving prenatal care at various medical institutions in Minhang District, Shanghai, from March to June 2023. The survey included inquiries about demographic information, knowledge, and perception of influenza disease and influenza vaccine. Logistic regression models and chi-square tests were used to analyze the data. 6.9% (78/1125) of participants considered receiving the influenza vaccine during pregnancy. Participants with graduate education or above (OR = 4.632, 95%CI: 1.046-20.517), non-office workers (OR = 2.784, 95%CI: 1.560-4.970), and participants whose spouses were not office workers (OR = 0.518, 95% CI: 0.294-0.913) were significantly associated with high intent to vaccinate. Participants with superior knowledge (>30 points) exhibited greater willingness (p < .001). Participants who viewed post-influenza symptoms as mild had a significantly lower willingness to vaccinate during pregnancy (2.3%), compared to those who disagreed (p = .015). Conversely, those recognizing a heightened risk of hospitalization due to respiratory diseases in pregnant women post-influenza were significantly more inclined to vaccinate during pregnancy (8.8%) (p = .007). Participants recognizing benefits uniformly expressed willingness to receive the influenza vaccine during pregnancy (p < .001), while those perceiving barriers uniformly rejected vaccination (p < .001). Higher education, non-office worker status, and having an office worker spouse correlate with greater willingness to receive the influenza vaccine during pregnancy. Enhanced knowledge and accurate perceptions of influenza and its vaccine influenced willingness. Accumulating knowledge about influenza and its vaccine fosters accurate perceptions. Notably, overall willingness to vaccinate during pregnancy remains low, likely due to safety concerns, and lack of accurate perceptions. Targeted health education, improved communication between healthcare providers and pregnant women, and campaigns highlighting vaccine benefits for mothers and children are essential.

A novel scale for assessing the risk of low birthweight: Birthweight questionnaire

BACKGROUND

The birthweight of a newborn is critical to their health, development, and well-being. Previous studies that used maternal characteristics to predict birthweight did not employ a harmonised scale to assess the risk of low birthweight (LBW).

OBJECTIVE

The goal of this study was to develop a new instrument that uses items on a uniform scale to assess the risk of an LBW in a pregnant woman.

METHODS

Item response theory was employed to evaluate a similar existing scale, and some weaknesses were identified.

RESULTS

Based on the observed weaknesses of the existing scale, a new uniform scale was developed, which is a 3-point Likert scale consisting of seven items.

CONCLUSION

The scale, termed birthweight questionnaire, is a valuable tool for collecting data that could assist in assessing the risk of an LBW at every stage of pregnancy.

Vaccination: Adherence and Hesitancy among Pregnant Women for COVID-19, Pertussis, and Influenza Vaccines

In the realm of antenatal care, vaccinations serve as a cornerstone, crucial for safeguarding the health of both the mother and the fetus, while also extending protection to the newborn against communicable diseases. Nevertheless, vaccine adherence among pregnant women remains very low. The aim of our study was to evaluate the uptake of vaccines (influence, pertussis, and COVID-19) among women during pregnancy and to understand pregnant women's knowledge of vaccines and the diseases they protect against. The purpose was to investigate the reasons why pregnant women chose not to be vaccinated and to develop effective strategies for informing them about the importance of vaccination for both maternal and fetal safety. A prospective observational study was conducted in the Department of Obstetrics and Gynaecology, "Ospedale Santa Maria della Misericordia" in Udine, from 1 December 2021 to 30 June 2022. During this period, a self-completed paper questionnaire was administered to women at the end of pregnancy or during the puerperium. A total of 161 questionnaires were collected. Higher educational level was found to be significantly associated with influenza vaccination uptake (p = 0.037, OR = 2.18, 95% CI 1.05-4.51). Similarly, for pertussis vaccination, adherence was mainly associated with higher educational level (p = 0.014, OR = 2.83, 95% CI 1.24-6.47), but also with Italian nationality (p = 0.003, OR = 3.36, 95% CI 1.56-8.43) and pregnancy attended by a midwife or private gynecologist (p = 0.028, OR = 0.39, 95% CI 0.17-0.90). Regarding the COVID-19 vaccine, the only factor positively influencing uptake was Italian nationality (p = 0.044, OR = 2.66, 95% CI 1.03-6.91). Women's fear that vaccines would endanger the fetus appeared to be the most important reason for refusing vaccinations. Simultaneously, patients also exhibited a desire to receive more information about maternal vaccination, particularly from their general physician or gynecologist. For this reason, it is imperative to enhance maternal vaccination counselling, making it a routine step in prenatal care from the first antenatal visit until the postpartum period.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Interventional study to improve pertussis and influenza vaccination uptake in pregnant women

OBJECTIVES

Pertussis and influenza are endemic infections and associated with relevant morbidity and mortality in newborns and young infants. The Swiss Federal Office of Public Health has recommended influenza vaccination since 2011 and pertussis vaccination in pregnancy (ViP) since 2013 and expanded to repetition in each pregnancy since 2017. ViP is safe and effective in preventing severe diseases, but implementation is a challenge. We hypothesized that the proportion of women receiving ViP is persistently low despite existing national recommendations. Our primary objective was to compare the proportion of pertussis and influenza vaccine recommendations for and its acceptance by pregnant women before and after an information campaign tailored to obstetricians. Secondly, we aimed to identify reasons for missing or declining ViP.

STUDY DESIGN

We conducted a prospective, single-center, single-arm implementation study in the maternity ward at the University Women's Hospital Basel. We performed standardized interviews with women hospitalized for postpartum care before (October to December 2019, Phase 1, n = 262) and after an information campaign (October to December 2020, Phase 2, n = 233) and compared categorical variables using chi-squared or Fisher's exact test and continuous variables using Whitney Mann U test.

RESULTS

We found no significant differences in the proportion of recommendation for pertussis ViP (80 % vs. 84 %, p = 0.25) and implementation (76 % vs. 78 %, p = 0.63) between Phase 1 and 2. Main reasons for missing or declining vaccinations were lack of recommendation (62.8 %) and safety concerns regarding the unborn child (17.7 %). In contrast, the proportion of recommendation for influenza ViP (45 % vs. 63 %, p < 0.001) and implementation (29 % vs. 43 %, p < 0.001) increased significantly.

CONCLUSION

Proactive recommendations by obstetricians play a key role in the implementation of ViP but is still insufficient in our setting. We believe that future efforts should aim to explore possible hurdles that impede recommendations by obstetricians for ViP. The focus should be on the needs and experiences of obstetricians in private practice, but also other health care professionals involved in care of pregnant women. Local campaigns do not seem effective enough, therefore national campaigns with new strategies are desirable.

Viral infections in pregnancy and impact on offspring neurodevelopment: mechanisms and lessons learned

Pregnant individuals with viral illness may experience significant morbidity and have higher rates of pregnancy and neonatal complications. With the growing number of viral infections and new viral pandemics, it is important to examine the effects of infection during pregnancy on both the gestational parent and the offspring. Febrile illness and inflammation during pregnancy are correlated with risk for autism, attention deficit/hyperactivity disorder, and developmental delay in the offspring in human and animal models. Historical viral epidemics had limited follow-up of the offspring of affected pregnancies. Infants exposed to seasonal influenza and the 2009 H1N1 influenza virus experienced increased risks of congenital malformations and neuropsychiatric conditions. Zika virus exposure in utero can lead to a spectrum of abnormalities, ranging from severe microcephaly to neurodevelopmental delays which may appear later in childhood and in the absence of Zika-related birth defects. Vertical infection with severe acute respiratory syndrome coronavirus-2 has occurred rarely, but there appears to be a risk for developmental delays in the infants with antenatal exposure. Determining how illness from infection during pregnancy and specific viral pathogens can affect pregnancy and neurodevelopmental outcomes of offspring can better prepare the community to care for these children as they grow. IMPACT: Viral infections have impacted pregnant people and their offspring throughout history. Antenatal exposure to maternal fever and inflammation may increase risk of developmental and neurobehavioral disorders in infants and children. The recent SARS-CoV-2 pandemic stresses the importance of longitudinal studies to follow pregnancies and offspring neurodevelopment.

An Observational Study on the Pharmacokinetics of Oseltamivir in Lactating Influenza Patients

Influenza infection may lead to serious complications in the postpartum period, therefore, oseltamivir treatment in these patients and their breastfed infants is of great importance. However, the pharmacokinetics of oseltamivir in postpartum lactating women with acute influenza infection, and the consequent infant exposure to oseltamivir are still unknown, and these data would help in assessing risk and the need for dose adjustment in breastfed infants. Six lactating women with influenza-like symptoms, at a standard dose of 75 mg oral oseltamivir twice daily for 5 days, were recruited in this phase IV clinical study during the 2011/2012 H1N1 pandemic seasons. Breast milk/colostrum and venous blood samples were taken at multiple timepoints, maternal urine samples were obtained from total output within the 12-hour observational period following the seventh dose of oseltamivir. Oseltamivir phosphate (OP) reached a maximum 69.5 ± 29.4 ng/mL concentration in breast milk, higher than that found in the plasma, and showed elimination within ~ 8 hours. Oseltamivir carboxylate (active metabolite of OP) showed a lower, nearly steady-state concentration in breast milk during the observational period (maximum plasma concentration (Cmax ) = 38.4 ± 12.9 ng/mL). Based on estimated daily milk consumption of exclusively breastfed infants, their calculated daily exposure is < 0.1% of the infant dose of oseltamivir for treatment of influenza as per marketing authorization. Here, we provide the first maternal breast milk pharmacokinetic data for oral multiple-dose oseltamivir in lactating patients with influenza and showed that its concentration in the breast milk is not sufficient to reach a therapeutic dose for breastfed infants.

Pregnant women's attitudes and behaviours towards antenatal vaccination against Influenza and COVID-19 in the Liverpool City Region, United Kingdom: Cross-sectional survey

Objectives

Influenza poses a serious health risk to pregnant women and their babies. Despite this risk, influenza vaccine uptake in pregnant women in the UK is less than 50%. Little is known about how COVID-19 affects pregnant women, but its management may affect attitudes and behaviours towards vaccination in pregnancy. The study objectives were to establish attitudes and knowledge of pregnant women towards influenza disease and influenza vaccination and to compare these to attitudes and knowledge about COVID-19 and COVID-19 vaccination.

Design

A cross-sectional survey was conducted using an online questionnaire distributed through local advertisement and social media outlets. Information was sought on attitudes and knowledge of influenza and COVID-19 and their respective vaccines.

Participants and setting

Pregnant women residing in Liverpool City Region, UK.

Results

Of the 237 respondents, 73.8% reported receiving an influenza vaccine. Over half (56.5%) perceived themselves to be at risk from influenza, 70.5% believed that if they got influenza, their baby would get ill, and 64.6% believed getting influenza could hurt their baby, 60.3% believed that the influenza vaccine would prevent their baby from getting ill, and 70.8% believed it would protect their baby. Only 32.9% of respondents stated they would receive the COVID-19 vaccine if it were available to them. However, 80.2% stated they would receive a COVID-19 vaccine if they were not pregnant. Most of the women stated that they would accept a vaccine if recommended to them by healthcare professionals.

Conclusions

Acceptance of the influenza and COVID-19 vaccines during pregnancy seems to be more related to the safety of the baby rather than the mother. Women perceived their child to be more at risk than themselves. Information about influenza and COVID-19 vaccine safety as well as healthcare provider recommendations play an important role in vaccine uptake in pregnant women.

Assessing the Presence of IgG Antibodies against Influenza Viruses in Neonates after Maternal Vaccination and Factors That May Affect the Transplacental Transfer

Special populations, particularly pregnant women, are uniquely susceptible to infectious diseases due to alterations in their immunological, respiratory, and cardiovascular systems during gestation. Influenza infections during the perinatal period have been associated with more severe maternal and perinatal outcomes, underscoring the critical importance of vaccination data for pregnant women. According to the World Health Organization (WHO), all pregnant women and those of childbearing age should receive the inactivated influenza vaccine, irrespective of their pregnancy stage. This study aimed to elucidate factors influencing neonatal antibody presence following maternal influenza vaccination. Conducted through convenience sampling in Athens, Greece, this study involved 78 pregnant women who received flu vaccinations. The participants completed questionnaires covering demographics, obstetric history, attitudes toward influenza vaccination, and knowledge about the influenza virus and pregnancy vaccination. Blood samples were collected from 83 neonates to assess IgG antibody presence. Five of the surveyed women had twin pregnancies. The statistical analysis employed IBM SPSS-Statistics version 26.0. This study revealed the presence of positive influenza A and B antibodies in neonates following maternal immunization. Furthermore, it identified factors such as the gestational week and timing of vaccination during pregnancy that influenced the transfer of antibodies from mother to fetus. These findings offer valuable insights for healthcare professionals to provide informed recommendations on influenza vaccination during pregnancy and empower expectant mothers to make informed decisions about the benefits of immunization.

Coverage and predictors of influenza and pertussis vaccination during pregnancy: a whole of population-based study

BACKGROUND

Respiratory infections including influenza and pertussis are associated with significant morbidity and mortality in mothers and newborns. Vaccination during pregnancy against influenza and pertussis is recommended for all women but data on uptake in Australia is limited.

METHODS

We conducted a retrospective population-based cohort study in Australia's largest state, New South Wales (NSW), using a Perinatal Data Collection (PDC). Data included demographic, pregnancy, and birth details including pertussis and influenza vaccination during pregnancy for all women giving birth between 01 January 2016 and 31 December 2020. We used descriptive statistics to assess uptake of influenza and pertussis vaccination during pregnancy and Poisson loglinear regression to estimate associations between maternal characteristics and vaccine receipt.

RESULTS

During 2016-2020, there were 477,776 births (mean maternal age 32.25 years). In 176,255 (36.9%) births the mother received both vaccines; 202,922 (42.5%) influenza and 315,620 (66.1%) pertussis vaccine. From 2016 to 2020, reported coverage increased from 26.7% to 58.7% for influenza and 43.1% to 78.8% for pertussis, respectively. After adjustment, characteristics associated with lower likelihood of receiving influenza and pertussis vaccination included: younger age (<30 years), being born in Australia/New Zealand, from lower socio-economic strata, having previous pregnancies, being later to first antenatal care, utilising the public hospital care model, smoking, having chronic hypertension and BMI > 25 kg/m2.

CONCLUSIONS

While reported coverage of both influenza and pertussis vaccine in birthing women in NSW has increased over time, disparities in coverage exist and they highlight areas where evidence-based interventions to improve maternal vaccination could be targeted.

Management of influenza - updated Swedish guidelines for antiviral treatment

Influenza causes seasonal epidemics of respiratory infection in all parts of the world. Manifestations of influenza range from mild upper to severe lower respiratory tract infection. Medical risk groups are defined by factors predisposing for development of severe disease and are recommended annual vaccination as a protective measure. The previous Swedish treatment guidelines for influenza were issued in 2011, and a review of current evidence was deemed relevant. An important reason to revisit the guidelines is the recent approval of a novel drug for influenza treatment, baloxavir. Updated Swedish evidence-based guidelines created by a group of experts from various research areas, for the management of influenza are presented here. The work has been made in collaboration with the Public Health Agency of Sweden and the Swedish Reference Group for AntiViral therapy (RAV). The updated guidelines include guidelines for diagnostics, treatment and prophylaxis in special groups, including management of pregnant women and children with influenza. A new section about infection control has been added. Pharmacological treatment is covered in detail with regards to indication and dosage. Additionally, drug resistance and environmental aspects are discussed.

Vaccine hesitancy and knowledge regarding maternal immunization among reproductive age women in central Italy: a cross sectional study

Background

Vaccination in pregnancy offers protection to the mother and the newborn. In Italy, influenza, pertussis, and COVID-19 vaccinations are recommended in pregnancy, but vaccination coverage is still far from the National Immunization Plan goals. We aimed to assess knowledge and attitude on maternal immunization in two groups of Italian women, in pregnancy and in reproductive age (non pregnant).

Methods

A cross sectional study on Italian childbearing age women gathering information on their knowledge on maternal immunization and attitudes to receiving influenza and pertussis vaccines in pregnancy was carried out at the University of Rome Tor Vergata, between September 2019 and February 2020. Logistic and multinomial regressions were chosen as statistical tests for our analysis.

Results

1,031 women participated in the survey by answering the questionnaire. Out of these, 553 (53.6%) women were pregnant, and 478 (46.4%) were in the reproductive age. 37% (204/553) of pregnant women and 41% (198/476) of non pregnant women are aware of the existence of an immunization plan for pregnant women in Italy. The group with age between 20 and 30, for both pregnant women and women in the reproductive age, has a better knowledge of vaccination in pregnancy. Working status is a variable associated with more awareness about vaccination during pregnancy only for pregnant women (OR = 2.34, p < 0.00001). Educational status, trimester of pregnancy and knowledge on the topic are associated with vaccine hesitancy in our multivariate analysis for pregnant women. In the reproductive age group women who had a previous pregnancy are more likely to be hesitant towards vaccination in pregnancy, on the other hand the one with a higher knowledge and educational status are more likely to get vaccinated.

Conclusions

The study highlights the persistent vaccine hesitancy among Italian women of reproductive age and pregnant women. Despite healthcare providers being identified as a reliable source of information, their recommendations alone are insufficient to overcome vaccine hesitancy. Factors such as employment status, educational level, pregnancy trimester, and knowledge about vaccinations during pregnancy influence vaccine hesitancy. Tailored educational interventions and communication campaigns targeting these areas can help reduce vaccine hesitancy and promote maternal immunization.

Influenza A virus infection during pregnancy causes immunological changes in gut-associated lymphoid tissues of offspring mice

Maternal influenza A virus (IAV) infection during pregnancy can affect offspring immune programming and development. Offspring born from influenza-infected mothers are at increased risk of neurodevelopmental disorders and have impaired respiratory mucosal immunity against pathogens. The gut-associated lymphoid tissue (GALT) represents a large proportion of the immune system in the body and plays an important role in gastrointestinal (GI) homeostasis. This includes immune modulation to antigens derived from food or microbes, gut microbiota composition, and gut-brain axis signaling. Therefore, in this study, we investigated the effect of maternal IAV infection on mucosal immunity of the GI tract in the offspring. There were no major anatomical changes to the gastrointestinal tract of offspring born to influenza-infected dams. In contrast, maternal IAV did affect the mucosal immunity of offspring, showing regional differences in immune cell profiles within distinct GALT. Neutrophils, monocytes/macrophages, CD4+ and CD8+ T cells infiltration was increased in the cecal patch offspring from IAV-infected dams. In the Peyer's patches, only activated CD4+ T cells were increased in IAV offspring. IL-6 gene expression was also elevated in the cecal patch but not in the Peyer's patches of IAV offspring. These findings suggest that maternal IAV infection perturbs homeostatic mucosal immunity in the offspring gastrointestinal tract. This could have profound ramifications on the gut-brain axis and mucosal immunity in the lungs leading to increased susceptibility to respiratory infections and neurological disorders in the offspring later in life.NEW & NOTEWORTHY Influenza A virus (IAV) infection during pregnancy is associated with changes in gut-associated lymphoid tissue (GALT) in the offspring in a region-dependent manner. Neutrophils and monocytes/macrophages were elevated in the cecal patch of offspring from infected dams. This increase in innate immune cell infiltration was not observed in the Peyer's patches. T cells were also elevated in the cecal patch but not in the Peyer's patches.

A colloidal gold test strip based on catalytic hairpin assembly for the clinical detection of influenza a virus nucleic acid

Influenza A epidemics, which occur annually in varying degrees worldwide, is a global challenge to healthcare facilities owing to several limitations of the current detection methods. Therefore, the development of a rapid, convenient, and economical method for the early diagnosis of influenza A will aid clinical treatment and epidemic control. Currently, most of the commonly used clinical rapid tests utilize colloidal gold test strips that detect specific influenza virus antigens but are limited by low sensitivity. Therefore, this study combined catalytic hairpin assembly (CHA) with colloidal gold immunochromatographic assay (GICA) to develop a highly sensitive and visual CHA-GICA test strip. Clinical sample analysis revealed that the sensitivity of the assay was 81.8% and 74% under optimal (35 °C) and room temperature (25 °C) conditions, respectively. In conclusion, this study developed a rapid nucleic acid assay for detecting influenza A virus with high sensitivity and specificity, which can improve the clinical detection of influenza A.

Vaccination against influenza in pregnant women in a maternity hospital in the Czech Republic in the season 2020-2021

OBJECTIVES

Pregnant women are among the priority groups to receive influenza vaccines in the Czech Republic since 2011, data on vaccination coverage are not yet available. The aim of the study was to determine the influenza vaccination coverage (IVC) and provide source data for further activities.

METHODS

A prospective observational study was performed in a large maternity hospital in Prague. The self-completed questionnaire was distributed to 5,475 pregnant women between September 1, 2020 and August 31, 2021. Questions included maternal sociodemographic characteristics, influenza vaccination status and sources of maternal vaccination recommendations during pregnancy.

RESULTS

A total of 4,617 completed questionnaires have been analysed. The median age of study participants (N = 4,592) was 33 years (range: 18-51 years). The majority (69.7%) of women had completed their university education, most women were childless (58.5%) or had one child (32.5%) before the start of the study. Less than 2% of women reported being vaccinated against influenza during their pregnancy (1.5%; 95% CI, 1.1-1.9%). Only 21% of women knew that it's possible to get vaccinated against influenza during pregnancy. Participants considered influenza vaccination in pregnancy as important (3.3%), useful (41.1%) and useless (44.4%). Out of 959 pregnant women who had information about influenza vaccination during pregnancy, only 6.9% were vaccinated, while among those who did not have this information, 0.1% were vaccinated during pregnancy (p < 0.001). The most frequent source of information was Internet, then media and a general practitioner.

CONCLUSIONS

The IVC during pregnancy in our study was extremely low. In order to improve IVC among pregnant women, it is necessary to increase awareness of recommendations and vaccination options among the public and professionals and incorporating vaccination recommendation in routine antenatal practice.

Inequity of antenatal influenza and pertussis vaccine coverage in Australia: the Links2HealthierBubs record linkage cohort study, 2012-2017

BACKGROUND

Pregnancy and early infancy are increased risk periods for severe adverse effects of respiratory infections. Aboriginal and/or Torres Strait Islander (respectfully referred to as First Nations) women and children in Australia bear a disproportionately higher burden of respiratory diseases compared to non-Indigenous women and infants. Influenza vaccines and whooping cough (pertussis) vaccines are recommended and free in every Australian pregnancy to combat these infections. We aimed to assess the equity of influenza and/or pertussis vaccination in pregnancy for three priority groups in Australia: First Nations women; women from culturally and linguistically diverse (CALD) backgrounds; and women living in remote areas or socio-economic disadvantage.

METHODS

We conducted individual record linkage of Perinatal Data Collections with immunisation registers/databases between 2012 and 2017. Analysis included generalised linear mixed model, log-binomial regression with a random intercept for the unique maternal identifier to account for clustering, presented as prevalence ratios (PR) and 95% compatibility intervals (95%CI).

RESULTS

There were 445,590 individual women in the final cohort. Compared with other Australian women (n = 322,848), First Nations women (n = 29,181) were less likely to have received both recommended antenatal vaccines (PR 0.69, 95% CI 0.67-0.71) whereas women from CALD backgrounds (n = 93,561) were more likely to have (PR 1.16, 95% CI 1.10-1.13). Women living in remote areas were less likely to have received both vaccines (PR 0.75, 95% CI 0.72-0.78), and women living in the highest areas of advantage were more likely to have received both vaccines (PR 1.44, 95% CI 1.40-1.48).

CONCLUSIONS

Compared to other groups, First Nations Australian families, those living in remote areas and/or families from lower socio-economic backgrounds did not receive recommended vaccinations during pregnancy that are the benchmark of equitable healthcare. Addressing these barriers must remain a core priority for Australian health care systems and vaccine providers. An extension of this cohort is necessary to reassess these study findings.

The association between maternal influenza vaccination during pregnancy and adverse birth outcomes in the United States: Pregnancy risk Assessment Monitoring System (PRAMS)

OBJECTIVE

Influenza vaccination during pregnancy is highly recommended. We examined the association between maternal influenza vaccination and adverse birth outcomes.

METHODS

This cross-sectional study used data from the Pregnancy Risk Assessment Monitoring System (PRAMS) during 2012-2017. The primary exposure was the receipt of influenza vaccination during pregnancy. Low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA) were the primary outcomes. We conducted multivariable logistic regression models to estimate the adjusted odds ratios (AOR) and 95% confidence intervals (CI). Covariates used to adjust confounding included maternal age, marital status, education, race and ethnicity, insurance status before pregnancy, and smoking status. For a subgroup in 2012-2015, we analyzed the association between influenza vaccination in each trimester and adverse birth outcomes.

RESULTS

During 2012-2017, compared with unvaccinated women, women vaccinated during pregnancy had a lower risk of LBW and PTB. During 2012-2015, maternal influenza vaccination in the 1st and 3rd trimesters was associated with a reduced risk of LBW and PTB, and vaccination in the 3rd trimester had a greater protective effect than in the 1st trimester. Influenza vaccination was not associated with SGA regardless of trimester.

CONCLUSIONS

Our findings suggest that influenza vaccination during pregnancy is a safe and effective way to protect newborns.

Effect of COVID-19 on antenatal care: experiences of medical professionals in the Netherlands

BACKGROUND

COVID-19 has greatly affected the delivery of all health care services globally. Antenatal care is one area of care that has been impacted, despite the fact that attending antenatal check-ups is essential for pregnant women and cannot be postponed. Little is known about how exactly ANC provision has changed in the Netherlands, or how the changes have impacted midwives and gynaecologists providing those services.

METHODS

This study used a qualitative research design to investigate changes in individual and national practice following the onset of the COVID-19 pandemic. The study involved a document analysis of protocols and guidelines for ANC provision to evaluate how those changed following the onset of the COVID-19 pandemic and semi-structured interviews with ANC care providers (i.e., gynaecologists and midwives).

RESULTS

Guidance was issued by multiple organizations, during the pandemic, on how to approach the risk of infection in pregnant women, recommending several changes to ANC to protect both pregnant women and ANC providers. Both midwives and gynaecologists reported changes in their practice. With less face-to-face consultations happening, digital technologies became critical in the care of pregnant women. Shorter and fewer visits were reported, with midwifery practices adjusting their guidelines further than hospitals. Challenges, with high workloads and lack of personal protective equipment were discussed.

CONCLUSIONS

The COVID-19 pandemic has had an immense impact on the health care system. This impact has had both negative and positive effects on the provision of ANC in the Netherlands. It is important to learn from the current COVID-19 pandemic and adapt ANC, as well as health care systems as a whole, to be better prepared for future health crises and ensure continuous provision of good quality care.

Surveillance Systems for Monitoring Vaccination Coverage with Vaccines Recommended for Pregnant Women, United States

Pregnant women* and their infants are at increased risk for serious influenza, pertussis, and COVID-19-related complications, including preterm birth, low-birth weight, and maternal and fetal death. The advisory committee on immunization practices recommends pregnant women receive tetanus-toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy, and influenza and COVID-19 vaccines before or during pregnancy. Vaccination coverage estimates and factors associated with maternal vaccination are measured by various surveillance systems. The objective of this report is to provide a detailed overview of the following surveillance systems that can be used to assess coverage of vaccines recommended for pregnant women: Internet panel survey, National Health Interview Survey, National Immunization Survey-Adult COVID Module, Behavioral Risk Factor Surveillance System, Pregnancy Risk Assessment Monitoring System, Vaccine Safety Datalink, and MarketScan. Influenza, Tdap, and COVID-19 vaccination coverage estimates vary by data source, and select estimates are presented. Each surveillance system differs in the population of pregnant women, time period, geographic area for which estimates can be obtained, how vaccination status is determined, and data collected regarding vaccine-related knowledge, attitudes, behaviors, and barriers. Thus, multiple systems are useful for a more complete understanding of maternal vaccination. Ongoing surveillance from the various systems to obtain vaccination coverage and information regarding disparities and barriers related to vaccination are needed to guide program and policy improvements.

Timing and temporal trends of influenza and pertussis vaccinations during pregnancy in three Australian jurisdictions: The Links2HealthierBubs population-based linked cohort study, 2012-2017

BACKGROUND

Antenatal inactivated influenza (IIV) and pertussis-containing vaccines (dTpa) offer protection against severe respiratory infections for pregnant women and infants <6 months of age. Both vaccines are recommended in pregnancy; however, little is known about temporal or jurisdictional trends and predictors of uptake.

AIMS

To identify gaps and predictors of IIV and/or dTpa vaccinations in Australian pregnancies from 2012 to 2017.

MATERIALS AND METHODS

We conducted a probabilistically linked, multi-jurisdictional population-based cohort study, drawing from perinatal data collections and immunisation databases. We used a generalised linear mixed model with a random effect term to account for clustering of multiple pregnancies within mothers, to calculate vaccination uptake, and identify predictors of uptake by maternal demographic, pregnancy, and health characteristics.

RESULTS

Of 591 868 unique pregnancies, IIV uptake was 15%, dTpa 27% and 12% received both vaccines. Pertussis vaccinations in First Nations pregnancies were 20% lower than non-Indigenous pregnancies; dTpa was strongly associated with IIV uptake (risk ratio (RR): 8.60, 95% CI 8.48-8.73). This trend was temporally and jurisdictionally consistent. First Nations women were more likely to have had IIV in pregnancy before the introduction of dTpa in the pregnancy program: (RR: 1.48, 95% CI 1.40-1.57), but less likely after dTpa implementation (RR: 0.78, 95% CI 0.76-0.80).

CONCLUSIONS

Inequity in vaccine uptake between First Nations and non-Indigenous pregnancies, and dismal rates of vaccination in pregnancy overall need urgent review, particularly before the next influenza pandemic or pertussis outbreak. If antenatal dTpa is driving IIV uptake, changes in antenatal healthcare practices are needed to ensure vaccines are offered equitably and optimally to protect against infection.

Hospital Admissions from the Emergency Department and Subsequent Critical Care Interventions for Influenza during Pregnancy

OBJECTIVE

The objectives of this study were to determine (1) whether obstetrical patients were more likely to be admitted from the emergency department (ED) for influenza compared with nonpregnant women, and (2) require critical care interventions once admitted.

STUDY DESIGN

Using data from the 2006 to 2011 Nationwide Emergency Department Sample, ED encounters for influenza for women aged 15 to 54 years without underlying chronic medical conditions were identified. Women were categorized as pregnant or nonpregnant using billing codes. Multivariable log linear models were fit to evaluate the relative risk of admission from the ED and the risk of intensive care unit (ICU)-level interventions including mechanical ventilation and central monitoring with pregnancy status as the exposure of interest. Measures of association were described with adjusted risk ratios (aRRs) with 95% confidence intervals (CIs).

RESULTS

We identified 15.9 million ED encounters for influenza of which 4% occurred among pregnant women. Pregnant patients with influenza were nearly three times as likely to be admitted as nonpregnant patients (aRR = 2.99, 95% CI: 2.94, 3.05). Once admitted, obstetric patients were at 72% higher risk of ICU-level interventions (aRR = 1.72, 95% CI: 1.61, 1.84). Of pregnant women admitted from the ED, 9.3% required ICU-level interventions such as mechanical ventilation or central monitoring. Older patients and those with Medicare were also at high risk of admission and ICU-level interventions (p < 0.01).

CONCLUSION

Pregnancy confers three times the risk of admission from the ED for influenza and pregnant women are significantly more likely to require ICU-level medical interventions compared with women of similar age. These findings confirm the significant disease burden from influenza in the obstetric population and the public health importance of reducing infection risk.

KEY POINTS

· Pregnancy confers three times the risk of admission from the ED for influenza.. · Pregnant women admitted with influenza are significantly more likely to require ICU-level care.. · Influenza represents a significant disease burden in the obstetric population.

Mild and asymptomatic influenza B virus infection among unvaccinated pregnant persons: Implication for effectiveness of non-pharmaceutical intervention and vaccination to prevent influenza

BACKGROUND

We estimated symptomatic and asymptomatic influenza infection frequency in community-dwelling unvaccinated pregnant persons to inform risk communication.

METHODS

We collected residue sera from multiple antenatal-care blood draws during October 2016-April 2017. We determined influenza infection as seroconversion with ≥ 4-fold rise in antibody titers between any two serum samples by improved hemagglutinin-inhibition assay including ether-treated B antigens. The serology data were linked to the results of nuclei acid testing (rRT-PCR) based on acute respiratory illness (ARI) surveillance.

RESULTS

Among all participants, 43 %(602/1384) demonstrated serology and/or rRT-PCR evidenced infection, and 44 %(265/602) of all infections were asymptomatic. ARI-associated rRT-PCR testing identified only 10 %(61/602) of total infections. Only 1 %(5/420) of the B Victoria cases reported ARI and had a rRT-PCR positive result, compared with 33 %(54/165) of the H3N2 cases. Among influenza ARI cases with multiple serum samples, 19 %(11/58) had seroconversion to a different subtype prior to the illness.

CONCLUSIONS

The incidence of influenza B infection in unvaccinated pregnant persons is under-estimated substantially. Non-pharmaceutical intervention may have suboptimal effectiveness in preventing influenza B transmission due to the less clinical manifestation compared to influenza A. The findings support maternal influenza vaccination to protect pregnant persons and reduce consequent household transmission.

Maternal and Neonatal Outcomes of COVID-19 Infection in Pregnancy

BACKGROUND

Limited data is available on the full spectrum of maternal COVID-19 infection in terms of pregnancy outcomes. The present study aimed to compare the maternal and neonatal outcomes of COVID-19 in infected and non-infected pregnant women.

METHODS

A dual-site retrospective cohort study was conducted in two tertiary hospitals in Isfahan, Iran. The sample included 104 infected and 210 non-infected hospitalized pregnant women. Odds ratios (OR) were estimated using multivariate logistic regression.

RESULTS

There were significant differences between COVID-19-infected and non-infected pregnant women regarding preterm labor (PTL) (odds ratio [OR]: 11.34, 95% confidence interval [CI]: 1.19-48.54, P=0.035); hospitalization days (OR: 7.21, 95% CI: 4.05-12.85, P≤0.001); cesarean section (CS) (OR: 4.76, 95% CI: 1.78-12.45, P=0.002); neonatal admission to neonatal intensive care unit (NICU) (OR: 1.28, 95% CI: 1.12-1.67, P=0.004); and neonatal respiratory distress (OR: 2.37, 95% CI: 1.02- 5.47, P=0.044). No significant association was found between COVID-19 infection and abortion (OR: 0.06, 95% CI: 0.01-1.45, P=0.084); stillbirth (OR: 1.84, 95% CI: 0.05-39.68, P=0.743); Apgar score (1 minute) (OR: 0.91, 95% CI: 0.74-1.13, P=0.382); Apgar score (5 minutes) (OR: 0.97, 95% CI: 0.81-1.18, P=0.765); and low birth weight (LBW) (OR: 4.76, 95% CI: 1.78-12.45, P=0.002).

CONCLUSION

PTL, CS, neonatal admission in NICU, neonatal respiratory distress, and hospitalization days were significantly higher in pregnant women with COVID-19 compared to those without infection.

Respiratory viruses: their importance and lessons learned from COVID-19

Respiratory virus infection can cause severe illnesses capable of inducing acute respiratory failure that can progress rapidly to acute respiratory distress syndrome (ARDS). ARDS is related to poor outcomes, especially in individuals with a higher risk of infection, such as the elderly and those with comorbidities, i.e. obesity, asthma, diabetes mellitus and chronic respiratory or cardiovascular disease. Despite this, effective antiviral treatments available for severe viral lung infections are scarce. The coronavirus disease 2019 (COVID-19) pandemic demonstrated that there is also a need to understand the role of airborne transmission of respiratory viruses. Robust evidence supporting this exists, but better comprehension could help implement adequate measures to mitigate respiratory viral infections. In severe viral lung infections, early diagnosis, risk stratification and prognosis are essential in managing patients. Biomarkers can provide reliable, timely and accessible information possibly helpful for clinicians in managing severe lung viral infections. Although respiratory viruses highly impact global health, more research is needed to improve care and prognosis of severe lung viral infections. In this review, we discuss the epidemiology, diagnosis, clinical characteristics, management and prognosis of patients with severe infections due to respiratory viruses.

Influenza Virus Infection during Pregnancy as a Trigger of Acute and Chronic Complications

Influenza A virus (IAV) infection during pregnancy disrupts maternal and fetal health through biological mechanisms, which are to date poorly characterised. During pregnancy, the viral clearance mechanisms from the lung are sub-optimal and involve hyperactive innate and adaptive immune responses that generate wide-spread inflammation. Pregnancy-related adaptations of the immune and the cardiovascular systems appear to result in delayed recovery post-viral infection, which in turn promotes a prolonged inflammatory phenotype, increasing disease severity, and causing maternal and fetal health problems. This has immediate and long-term consequences for the mother and fetus, with complications including acute cardiopulmonary distress syndrome in the mother that lead to perinatal complications such as intrauterine growth restriction (IUGR), and birth defects; cleft lip, cleft palate, neural tube defects and congenital heart defects. In addition, an increased risk of long-term neurological disorders including schizophrenia in the offspring is reported. In this review we discuss the pathophysiology of IAV infection during pregnancy and its striking similarity to other well-established complications of pregnancy such as preeclampsia. We discuss general features of vascular disease with a focus on vascular inflammation and define the "Vascular Storm" that is triggered by influenza infection during pregnancy, as a pivotal disease mechanism for short and long term cardiovascular complications.

Mapping the maternal vaccination journey and influencing factors for Māori women in Aotearoa New Zealand: a qualitative study

Introduction Uptake of maternal vaccinations (MVs) is suboptimal in Aotearoa New Zealand, particularly for Māori. Aim To describe Māori women's journeys regarding maternal pertussis and influenza vaccinations and explore influences on uptake. Methods Semi-structured interviews were conducted in Waikato, Aotearoa New Zealand, with pregnant or recently pregnant Māori women, and separately with Māori healthcare professionals (HCPs) to understand women's decisions regarding MVs and enablers and barriers to uptake. Results Nine women and nine HCPs were interviewed. Verbal communications from midwives, general practice and pharmacy strongly influenced women's journeys. Women's decisions appeared largely straight-forward, with influences including awareness, knowledge, underlying beliefs and previous MVs. Enablers for MV uptake included HCPs' discussions, pro-vaccination beliefs, and accessibility. Barriers for MV uptake included poverty (and transport), lack of awareness, insufficient knowledge of benefits, late presentation to the midwife and other commitments or challenges in the women's lives affecting prioritisation of the vaccine. Misconceptions, seasonality, and lower HCP emphasis impaired influenza vaccination uptake. Discussion With multiple barriers to accessing MVs, HCPs who see pregnant women are the primary resource to improve awareness, knowledge, and access through kōrero (discussions) with the woman and, where possible, being able to administer the vaccinations. These HCPs need to be well-informed, aware of likely concerns women may have and how to address them, encourage these discussions and preferably be trusted.

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

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

Placental Vascular and Inflammatory Findings from Pregnancies Diagnosed with Coronavirus Disease 2019: A Systematic Review and Meta-analysis

We aimed to perform a meta-analysis of the literature concerning histopathologic findings in the placentas of women with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection during pregnancy. Searches for articles in English included PubMed, Web of Science, Google Scholar, and reference lists (up to April 2021). Studies presenting data on placental histopathology according to the Amsterdam Consensus Group criteria in SARS-CoV-2 positive and negative pregnancies were identified. Lesions were categorized into: maternal and fetal vascular malperfusion (MVM and FVM, respectively), acute placental inflammation with maternal and fetal inflammatory response (MIR and FIR, respectively), chronic inflammatory lesions (CILs), and increased perivillous fibrin deposition (PVFD). A total of 15 studies reporting on 19,025 placentas, n = 699 of which were derived from women who were identified as being infected with SARS-CoV-2 and 18,326 as SARS-CoV-2-negative controls, were eligible for analysis. No significant difference in incidence of MVM (odds ratio [OR]: 1.18, 95% confidence interval [CI]: 0.73-1.90), FVM (OR: 1.23, 95% CI: 0.63-2.42), MIR (OR: 0.66, 95% CI: 0.29-1.52) or FIR (OR: 0.85, 95% CI: 0.44-1.63), and CILs (OR: 0.97, 95% CI: 0.55-1.72) was found between placentae from gravida identified as being SARS-CoV-2 infected. However, placenta from gravida identified as being infected with SARS-CoV-2 were associated with significantly increased occurrence of PVFD (OR: 2.77, 95% CI: 1.06-7.27). After subgroup analyses based on clinical severity of COVID-19 infection, no significant difference was observed in terms of reported placental pathology between symptomatic or asymptomatic SARS-CoV-2 gravidae placenta. Current evidence based on the available literature suggests that the only pathologic finding in the placentae of women who are pregnant identified as having been infected with SARS-CoV-2 was an increased prevalence of PVFD. KEY POINTS: · No association between SARS-CoV-2 and maternal or fetal placental malperfusion.. · No association between SARS-CoV-2 and maternal or fetal inflammatory response.. · SARS-CoV-2 is associated with increased perivillous fibrin deposition in placenta..

Examining the impact of trimester of diagnosis on COVID-19 disease progression in pregnancy

BACKGROUND

COVID-19 infection is associated with increased morbidity in pregnancy and adverse maternal and neonatal outcomes. Little is currently known about how the timing of infection during pregnancy affects these outcomes.

OBJECTIVE

This study aimed to evaluate the effect of trimester of COVID-19 infection on disease progression and severity in pregnant patients.

STUDY DESIGN

This was a prospective cohort study of pregnant patients diagnosed with COVID-19 infection who delivered at a single urban hospital. Universal testing for SARS-CoV-2 was performed at hospital admission and for symptomatic patients in inpatient, emergency department, and outpatient settings. Disease severity was defined as asymptomatic, mild, moderate, severe, or critical on the basis of National Institutes of Health criteria. We evaluated disease progression from asymptomatic to symptomatic infection and from asymptomatic or mild infection to moderate, severe, or critical illness, and stratified by trimester of COVID-19 diagnosis. Primary outcomes included progression of COVID-19 disease severity and a composite obstetrical outcome, which included delivery at <37 weeks, preeclampsia with severe features, abruption, excess blood loss at delivery (>500 mL for vaginal or >1000 mL for cesarean delivery), and stillbirth.

RESULTS

From March 18, 2020 to September 30, 2021, 1326 pregnant patients were diagnosed with COVID-19 and delivered at our institution, including 103 (8%) first-, 355 (27%) second-, and 868 (65%) third-trimester patients. First-trimester patients were older and had more medical comorbidities; 86% of patients in all trimesters were Hispanic. Among patients admitted within 14 days of a positive test, 3 of 18 (17%) first-trimester, 20 of 47 (43%) second-trimester, and 34 of 574 (6%) third-trimester patients were admitted for the indication of COVID-19 illness. Across all trimesters, 1195 (90%) of 1326 COVID-19 infections were asymptomatic or mild, and 45 (10%) of 436 initially asymptomatic patients developed symptoms. Of patients with asymptomatic or mild symptoms at diagnosis, 4 (4%) of 93 first-, 18 (5%) of 337 second-, and 49 (6%) of 836 third-trimester patients developed moderate, severe, or critical illness (P=.80). There was no significant difference in composite obstetrical outcome with respect to trimester of COVID-19 diagnosis (24% first-trimester, 28% second-trimester, 28% third-trimester patients; P=.69).

CONCLUSION

Moderate, severe, or critical illness develops in almost 10% of pregnant patients. The frequency of COVID-19 disease progression in pregnancy does not differ by trimester of diagnosis.

The influence of COVID-19 pandemic on intrauterine fetal demise and possible vertical transmission of SARS-CoV-2

OBJECTIVE

The impact of COVID-19 on intrauterine fetal demise (IUFD) and vertical transmission of the SARS-CoV-2 from the mother to the fetus are crucial issues of the COVID-19 pandemic. In the current study, we aimed to detect the pandemic's influence on the IUFD and evaluate the vertical transmission of the SARS-CoV-2 through analysis of placental tissues collected from PCR positive women with IUFD above 20 weeks of gestation.

MATERIALS AND METHODS

The pregnant women above 20 weeks of gestation and had a fetus intrauterine demised during pandemic were included in the study. The pregnant women screened for COVID-19. Vertical transmission searched from placental tissues of COVID-19 positive women by RT-PCR tests for the presence of SARS-CoV-2 RNA. The number of IUFD before the pandemic and during the pandemic compared to assess the influence of the COVID-19 pandemic on the IUFD ratio.

RESULTS

Among 138 pregnant women with IUFD, 100 of them could screen for COVID-19 status. RT-PCR test results of 6 of the screened pregnant women were positive for SARS-CoV-2. Placental tissues of these six women were analyzed, and one test result was positive for SARS-CoV-2 RNA. The IUFD ratio was significantly increased during the pandemic.

CONCLUSION

It is clear that COVID-19 increases the IUFD ratio. Previous data for vertical transmission of SARS-CoV-2 during the second trimester is limited. We present the third case of literature that has positive placental results for SARS-CoV-2 RNA in the second trimester of pregnancy.

Multi-decade national cohort identifies adverse pregnancy and birth outcomes associated with acute respiratory illness hospitalisations during the influenza season

BACKGROUND

Despite the World Health Organization (WHO) recommendation that pregnant women be prioritised for seasonal influenza vaccination, coverage in the Western Pacific Region remains low. Our goal was to provide additional data for the Western Pacific Region about the value of maternal influenza vaccination to pregnant women and their families.

METHODS

We conducted a 16-year retrospective cohort to evaluate risks associated with influenza-associated maternal acute respiratory infection (ARI) in New Zealand. ARI hospitalisations during the May to September influenza season were identified using select ICD-10-AM primary and secondary discharge codes from chapter J00-J99 (diseases of the respiratory system). Cox proportional hazards models were used to calculate crude and adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

We identified 822,391 pregnancies among New Zealand residents between 2003 and 2018; 5095 (0.6%) had ≥1 associated ARI hospitalisation during the influenza season; these pregnancies were at greater risk of preterm birth (aHR 1.50, 95% CI 1.39-1.61) and low birthweight (aHR 1.64, 95% CI 1.51-1.79) than pregnancies without such hospitalisations. We did not find an association between maternal ARI hospitalisation and fetal death (aHR 0.96, 95% CI 0.69-1.34) during the influenza season. Maternal influenza vaccination was associated with reduced risk of preterm birth (aHR 0.79, 95% CI 0.77-0.82), low birthweight (aHR 0.87, 95% CI 0.83-0.90) and fetal death (aHR 0.50%, 95% CI 0.44-0.57).

CONCLUSION

In this population-based cohort, being hospitalised for an ARI during the influenza season while pregnant was a risk factor for delivering a preterm or a low birthweight infant and vaccination reduced this risk.

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

OBJECTIVE

To evaluate the association of community-level social vulnerability with COVID-19 vaccine hesitancy and vaccination among pregnant and postpartum individuals.

METHODS

Prospective cohort study assessing COVID-19 vaccine hesitancy among pregnant and postpartum individuals. We performed a baseline survey on COVID-19 vaccine hesitancy from 03/22/21 to 04/02/21, and a follow-up survey on COVD-19 vaccination status 3- to 6-months later. The primary exposure was the Centers for Disease Control and Prevention SVI (Social Vulnerability Index), measured in quartiles. Higher SVI quartiles indicated greater community-level social vulnerability with the lowest quartile (quartile 1) as the referent group. The primary outcome was COVID-19 vaccine hesitancy on the baseline survey (uncertainty or refusal of the vaccine), and the secondary outcome was self-report of not being vaccinated (unvaccinated) for COVID-19 on the follow-up survey.

RESULTS

Of 456 assessed individuals, 46% reported COVID-19 vaccine hesitancy on the baseline survey; and of 290 individuals (290/456, 64%) who completed the follow-up survey, 48% (140/290) were unvaccinated. The frequency of baseline vaccine hesitancy ranged from 25% in quartile 1 (low SVI) to 68% in quartile 4 (high SVI), and being unvaccinated at follow-up ranged from 29% in quartile 1 to 77% in quartile 4. As social vulnerability increased, the risk of COVID-19 vaccine hesitancy at baseline increased (quartile 2 aRR (adjusted relative risk): 1.46; 95% CI:0.98 to 2.19; quartile 3 aRR: 1.86; 95% CI:1.28 to 2.71; and quartile 4 aRR: 2.24; 95% CI:1.56 to 3.21), as did the risk of being unvaccinated at follow-up (quartile 2 aRR: 1.00; 95% CI:0.66 to 1.51; quartile 3 aRR: 1.68; 95% CI:1.17 to 2.41; and quartile 4 aRR: 1.82; 95% CI:1.30 to 2.56).

CONCLUSIONS

Pregnant and postpartum individuals living in an area with higher community-level social vulnerability were more likely to report COVID-19 vaccine hesitancy and subsequently to be unvaccinated at follow-up.

At the crux of maternal immune activation: Viruses, microglia, microbes, and IL-17A

Inflammation during prenatal development can be detrimental to neurodevelopmental processes, increasing the risk of neuropsychiatric disorders. Prenatal exposure to maternal viral infection during pregnancy is a leading environmental risk factor for manifestation of these disorders. Preclinical animal models of maternal immune activation (MIA), established to investigate this link, have revealed common immune and microbial signaling pathways that link mother and fetus and set the tone for prenatal neurodevelopment. In particular, maternal intestinal T helper 17 cells, educated by endogenous microbes, appear to be key drivers of effector IL-17A signals capable of reaching the fetal brain and causing neuropathologies. Fetal microglial cells are particularly sensitive to maternally derived inflammatory and microbial signals, and they shift their functional phenotype in response to MIA. Resulting cortical malformations and miswired interneuron circuits cause aberrant offspring behaviors that recapitulate core symptoms of human neurodevelopmental disorders. Still, the popular use of "sterile" immunostimulants to initiate MIA has limited translation to the clinic, as these stimulants fail to capture biologically relevant innate and adaptive inflammatory sequelae induced by live pathogen infection. Thus, there is a need for more translatable MIA models, with a focus on relevant pathogens like seasonal influenza viruses.

Maternal and neonatal immune response to SARS-CoV-2, IgG transplacental transfer and cytokine profile

SARS-CoV-2 infected pregnant women are at increased risk of severe COVID-19 than non-pregnant women and have a higher risk of adverse pregnancy outcomes like intrauterine/fetal distress and preterm birth. However, little is known about the impact of SARS-CoV-2 infection on maternal and neonatal immunological profiles. In this study, we investigated the inflammatory and humoral responses to SARS-CoV-2 in maternal and cord blood paired samples. Thirty-six pregnant women were recruited at delivery at Hospital Sant Joan de Déu, Barcelona, Spain, between April-August 2020, before having COVID-19 available vaccines. Maternal and pregnancy variables, as well as perinatal outcomes, were recorded in questionnaires. Nasopharyngeal swabs and maternal and cord blood samples were collected for SARS-CoV-2 detection by rRT-PCR and serology, respectively. We measured IgM, IgG and IgA levels to 6 SARS-CoV-2 antigens (spike [S], S1, S2, receptor-binding domain [RBD], nucleocapsid [N] full-length and C-terminus), IgG to N from 4 human coronaviruses (OC43, HKU1, 229E and NL63), and the concentrations of 30 cytokines, chemokines and growth factors by Luminex. Mothers were classified as infected or non-infected based on the rRT-PCR and serology results. Sixty-four % of pregnant women were infected with SARS-CoV-2 (positive by rRT-PCR during the third trimester and/or serology just after delivery). None of the newborns tested positive for rRT-PCR. SARS-CoV-2 infected mothers had increased levels of virus-specific antibodies and several cytokines. Those with symptoms had higher cytokine levels. IFN-α was increased in cord blood from infected mothers, and in cord blood of symptomatic mothers, EGF, FGF, IL-17 and IL-15 were increased, whereas RANTES was decreased. Maternal IgG and cytokine levels showed positive correlations with their counterparts in cord blood. rRT-PCR positive mothers showed lower transfer of SARS-CoV-2-specific IgGs, with a stronger effect when infection was closer to delivery. SARS-CoV-2 infected mothers carrying a male fetus had higher antibody levels and higher EGF, IL-15 and IL-7 concentrations. Our results show that SARS-CoV-2 infection during the third trimester of pregnancy induces a robust antibody and cytokine response at delivery and causes a significant reduction of the SARS-CoV-2-specific IgGs transplacental transfer, with a stronger negative effect when the infection is closer to delivery.

Outcomes in Pregnant Persons Immunized with a Cell-Based Quadrivalent Inactivated Influenza Vaccine: A Prospective Observational Cohort Study

Objective: To evaluate pregnancy and infant outcomes among persons immunized with a cell-based quadrivalent inactivated influenza vaccine (IIV4c) during routine pregnancy care. Design: Prospective observational cohort. Setting: US-based obstetrics/gynecology clinics. Population: Pregnant persons. This US-based, prospective observational cohort study evaluated the safety of quadrivalent inactivated influenza vaccine (IIV4c; Flucelvax® Quad) in pregnant persons immunized over 3 influenza seasons between 2017 and 2020. Pregnant persons were immunized with IIV4c as part of routine care, after which their health care provides HCPs with all observational data to a single coordinating center. Follow-up data were collected at the end of the second trimester and/or at the time of pregnancy outcome. A scientific advisory committee reviewed the data. Prevalence point estimates were reported with 95% confidence intervals (CIs). Pregnancy outcomes included: live birth, stillbirth, spontaneous abortion, elective termination, and maternal death. Infant outcomes included: preterm birth (<37 weeks gestational age), low birth weight (<2500 g), or major congenital malformations (MCMs). Of the 665 evaluable participants, 659 (99.1%) had a live birth. No stillbirths (0% [95% CI 0.0−0.6]), 4 spontaneous abortions (1.9% [0.5−4.8]), and 1 elective termination (0.5% [0.0−2.6]) were reported. Among 673 infants, 9.2% (upper 95% CI 11.5%) were born prematurely, 5.8% (upper 95% CI 7.6%) had low birth weight, and 1.9% (upper 95% CI 3.1%) were reported to have an MCM. No maternal deaths were reported. Of the 2 infants who died shortly after birth, one was adjudicated as not related to the vaccine; the other’s cause could not be determined due to maternal loss to follow-up. The prevalence of adverse pregnancy outcomes or preterm birth, low birth weight, or MCMs in newborns was similar in persons vaccinated with IIV4c compared to the rates observed in US surveillance systems. The safety profile of IIV4c in pregnant persons is consistent with previously studied influenza vaccines.

A Prospective Cohort Study on Pregnancy Outcomes of Persons Immunized with a Seasonal Quadrivalent Inactivated Influenza Vaccine during Pregnancy

This US-based, prospective observational cohort study evaluated the safety of a quadrivalent inactivated influenza vaccine (IIV4; Afluria Quadrivalent) in pregnant persons immunized over four influenza seasons between 2017 and 2021. Pregnancy outcomes included live birth, stillbirth, spontaneous abortion, and elective termination. Infant events of interest were major congenital malformations (MCMs), preterm birth (<37 weeks gestational age), and low birth weight (LBW). Data were descriptive; prevalence point estimates were reported with 95% confidence intervals (CI). A total of 483 pregnant persons were given IIV4 and evaluated; 477 (98.8%) reported a live birth, and there were 2 stillbirths, 4 spontaneous abortions, and no elective terminations or maternal deaths. The prevalence rates of infant events were as follows: preterm birth, 7.2% (upper 95% CI, 9.6%); LBW, 5.4% (upper 95% CI, 7.4%); and MCMs, 0.8% (upper 95% CI, 1.9%). Point estimates and upper 95% CIs of the observed prevalence rates were lower than or similar to background prevalence in the general US population. Our findings suggest no evidence of a safety concern with vaccinating this group at high risk of influenza complications and are consistent with published data from databases and surveillance systems that monitor the safety of influenza vaccines in pregnant persons.

Decreased Passive Immunity to Respiratory Viruses through Human Milk during the COVID-19 Pandemic

Infants may develop severe viral respiratory tract infections because their immune system is still developing in the first months after birth. Human milk provides passive humoral immunity during the first months of life. During the COVID-19 pandemic, circulation of common respiratory viruses was virtually absent due to the preventative measures resulting in reduced maternal exposure. Therefore, we hypothesized that this might result in lower antibody levels in human milk during the pandemic and, subsequently, decreased protection of infants against viral respiratory tract infections. We assessed antibody levels against respiratory syncytial virus (RSV), Influenza virus, and several seasonal coronaviruses in different periods of the COVID-19 pandemic in serum and human milk using a Luminex assay. IgG levels against RSV, Influenza, HCoV-OC43, HCoV-HKU1, and HCoV-NL63 in human milk were reduced with a factor of 1.7 (P < 0.001), 2.2 (P < 0.01), 2.6 (P < 0.05), 1.4 (P < 0.01), and 2.1 (P < 0.001), respectively, since the introduction of the COVID-19 restrictions. Furthermore, we observed that human milk of mothers that experienced COVID-19 contained increased levels of IgG and IgA binding to other respiratory viruses. Passive immunity via human milk against common respiratory viruses was reduced during the COVID-19 pandemic, which may have consequences for the protection of breastfed infants against respiratory infections. IMPORTANCE Passive immunity derived from antibodies in human milk is important for protecting young infants against invading viruses. During the COVID-19 pandemic, circulation of common respiratory viruses was virtually absent due to preventative measures. In this study, we observed a decrease in human milk antibody levels against common respiratory viruses several months into the COVID-19 pandemic. This waning of antibody levels might partially explain the previously observed surge of hospitalizations of infants, mostly due to RSV, when preventative hygiene measures were lifted. Knowledge of the association between preventative measures, antibody levels in human milk and subsequent passive immunity in infants might help predict infant hospital admissions and thereby enables anticipation to prevent capacity issues. Additionally, it is important in the consideration for strategies for future lockdowns to best prevent possible consequences for vulnerable infants.

Pregnant women and infants against the infection risk of COVID-19: a review of prenatal and postnatal symptoms, clinical diagnosis, adverse maternal and neonatal outcomes, and available treatments

BACKGROUND

The establishment of a risk-appropriate care approach for pregnant women and newborn infants under the COVID-19 pneumonia is vital to prevent the main pregnancy complications.

OBJECTIVES AND DESIGN

This study reviewed the vertical transmission (VT) potential of COVID-19 pneumonia in pregnant women. Key-related symptoms and adverse clinical outcomes for mothers and infants before and after childbirth were summarized. Some practical therapies and preventive health solutions were also proposed.

RESULTS

There was a high susceptibility in pregnant women to COVID-19 infection, especially in the third trimester of pregnancy. The most common symptoms in 22-40-year-old patients infected with COVID-19 were fever (87.6%), cough (52.3%), dyspnea (27.6%), fatigue (22.4%), sore throat (13.5%), malaise (9.4%), and diarrhea (3.4%), respectively. The viral infection led to an increase in preterm labor and cesarean delivery without any intrauterine infection and severe neonatal asphyxia. No infection in the newborn infants was reported despite a high risk of the VT phenomenon. The most important therapies were the reception of antiviral and antibiotic drugs, oxygenation therapy, psychological interventions, and food supplements with health-promoting effects. The best proposed medical strategies to control the COVID-19 infection were bi-monthly screening and following-up the mothers' and fetuses' health, not using the potent broad-spectrum antibiotics and corticosteroids, providing the delivery room with negative pressure for emergency cesarean section, and the immediate isolation of newborns after childbirth without direct breastfeeding.

CONCLUSION

Babies with respiratory problems may be born to some mothers with COVID-19, who have weak immune systems. Thus, the virus transmission cycle should be disrupted to prevent adverse maternal and fetal outcomes by integrating individual health guidelines, efficient medical care therapies, and hospital preventive practices.

Obstetric Provider Attitudes and Office Practices for Maternal Influenza and Tdap Vaccination

Background: Although maternal vaccination with influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines improve health outcomes for pregnant individuals and infants, maternal vaccination rates are low. This study assessed obstetric providers' attitudes and practices related to influenza and Tdap vaccination in four large health systems in New York (NY) and California (CA). Methods: We conducted a cross-sectional survey of all obstetric providers within four health systems (two in NY, two in CA) to evaluate provider attitudes and office systems used for Tdap and influenza vaccination. The survey assessed perceptions of influenza and Tdap vaccination based on the Health Belief Model, and assessed office systems (reminders, prompts, standing orders, and patient education) and communication with pregnant patients related to influenza and Tdap vaccines. Results: We had 112 responses (52% response rate) for analyses. Respondents strongly supported vaccination during pregnancy but viewed influenza disease as less of a concern for newborns than for pregnant individuals (40% vs. 67% considered influenza disease to be very significant, p < 0.001). Only 84% agreed that giving influenza vaccine in the first trimester is very safe. Patient vaccine refusal was the most commonly named barrier for both influenza and Tdap vaccination. Providers frequently used office system prompts, but did not frequently use standing orders, patient educational materials, vaccine champions, and feedback on vaccination rates. Conclusions: While most providers consider influenza and Tdap vaccination important during pregnancy, there is room for improvement in focusing on the importance of maternal vaccination to the health of the infant, and increasing the use of office systems to improve vaccination during pregnancy.

Obstetric risk in pregnancy interacts with hair cortisone levels to reduce gestational length

Background

Maternal psychological stress has been linked to preterm birth. However, the differential contribution of psychological stress versus stress hormones is not clear. Studies focus primarily on perceived stress and cortisol, with few assessing its inter-convertible hormone cortisone. Furthermore, little is known about the potential moderating roles of obstetric risk and fetal sex in the relationship between maternal stress and gestational length. This gap in knowledge is particularly evident for rural women who typically experience chronic multiple stressors during pregnancy. We explored the relationship of hormonal and psychological stress to gestational length and the effects of obstetric risks and fetal sex on this relationship among Kenyan pregnant women.

Methods

The sample included 130 women recruited between 22 to 28 weeks gestation. They completed a clinical and sociodemographic questionnaire together with the Perceived Stress Scale and provided a hair sample for cortisol and cortisone assay. Women underwent an ultrasound to assess weeks of gestation. At delivery, their pregnancy-related health problems were identified using information extracted from medical records to compile each woman's number of pregnancy risks on the Obstetric Medical Risk Index (OMRI).

Results

Perceived stress and hair cortisol were not significant predictors of gestational length. However, a greater number of obstetric risks on the OMRI was associated with shorter gestational length. This effect was further explained by the interaction between obstetric risk and hair cortisone (B = 0.709, p = 0.02). Hair cortisone levels of mothers who had a shorter gestation were significantly higher in mothers with 2 or more risks on the OMRI but not among mothers with only one or no risks (t = 2.39, p = 0.02). Fetal sex had no relationship to gestational length and also had no moderating effect on the relationship between any stress-related metric and gestational length.

Conclusion

Cortisone levels may increase in anticipation of shorter gestation as a compensatory response to increased obstetric risk. Elevated cortisone may be a more sensitive marker of risk for early delivery than cortisol or psychological stress, with salience for both the male and female fetus.

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

BACKGROUND

Maternal vaccinations for influenza and pertussis are recommended in New Zealand to protect mothers and their infant from infection. However, maternal immunisation coverage in New Zealand is suboptimal. Furthermore, there is unacceptable inequitable maternal immunisation rates across the country with Māori and Pacific women having significantly lower maternal immunisation rates than those of other New Zealanders.

METHODS

This research set out to explore what pregnant/recently pregnant Māori and Pacific women knew about immunisation during pregnancy and what factors influenced their decision to be vaccinated. A semi-structured interview guide was developed with questions focusing on knowledge of pertussis and influenza vaccination during pregnancy and decision-making. Māori and Pacific women aged over 16 years were purposively sampled and interviewed in Dunedin and Gisborne, New Zealand between May and August 2021. Interviews were analysed following a directed qualitative content approach. Data were arranged into coding nodes based on the study aims (deductive analysis) informed by previous literature and within these participant experiences were inductively coded into themes and subthemes.

RESULTS

Not all women were aware of maternal vaccine recommendations or they diseases they protected against. Many underestimated how dangerous influenza and pertussis could be and some were more concerned about potential harms of the vaccine. Furthermore, understanding potential harms of infection and protection provided by vaccination did not necessarily mean women would choose to be vaccinated. Those who decided to vaccinate felt well-informed, had vaccination recommended by their healthcare provider, and did so to protect their and their infant's health. Those who decided against vaccination were concerned about safety of the vaccines, lacked the information they needed, were not offered the vaccine, or did not consider vaccination a priority.

CONCLUSIONS

There is a lack of understanding about vaccine benefits and risks of vaccine-preventable diseases which can result in the reinforcement of negative influences such as the fear of side effects. Furthermore, if vaccine benefits are not understood, inaccessibility of vaccines and the precedence of other life priorities may prevent uptake. Being well-informed and supported to make positive decisions to vaccinate in pregnancy is likely to improve vaccine coverage in Māori and Pacific Island New Zealanders.

Maternal immune protection against infectious diseases

The maternal immune system protects developing offspring against pathogens before birth via transplacental transfer and after birth through secreted milk. This transferred maternal immunity influences each generation's susceptibility to infections and responsiveness to immunization. Thus, boosting immunity in the maternal-neonatal dyad is a potentially valuable public health strategy. Additionally, at critical times during fetal and postnatal development, environmental factors and immune stimuli influence immune development. These "windows of opportunity" offer a chance to identify both risk and protective factors that promote long-term health and limit disease. Here, we review pre- and postpartum maternal immune factors that protect against infectious agents in offspring and how they may shape the infant's immune landscape over time. Additionally, we discuss the influence of maternal immunity on the responsiveness to immunization in early life. Lastly, when maternal factors are insufficient to prevent neonatal infectious diseases, we discuss pre- and postnatal therapeutic strategies for the maternal-neonatal dyad.

Upregulated influenza A viral entry factors and enhanced interferon-alpha response in the nasal epithelium of pregnant rats

Despite the increased severity of influenza A infection in pregnancy, knowledge about the expression of cell entry factors for influenza A virus (IAV) and the innate immune response in the nasal epithelium, the primary portal of viral entry, is limited. Here, we compared the expression of IAV cell entry factors and the status of the innate immune response in the nasal epithelium of pregnant vs. non-pregnant female rats. IAV cell entry factors — sialic acid [SA] α-2,3- and α-2,6-linked glycans for avian and human IAV, respectively — were detected and quantified with lectin-based immunoblotting and flow cytometry. Baseline frequencies of innate immune cell phenotypes in single cell suspensions of the nasal epithelium were studied with flow cytometry. Subsequently, the magnitude of interferon and cytokine responses was studied with ELISA and cytokine arrays after intranasal resiquimod, a Toll-like receptor 7/8 agonist that mimics IAV infection. We noted substantially increased expression of cell entry factors for both avian and human IAV in the nasal epithelium during pregnancy. Assessment of the innate immune state of the nasal epithelium during pregnancy revealed two previously unreported features: (i) increased presence of tissue-resident plasmacytoid dendritic cells, and (ii) markedly enhanced release of interferon-α but not of the other interferons or cytokines 2 h after intranasal resiquimod. Collectively, our findings challenge the conventional notion of pregnancy-induced immunosuppression as a cause for severe influenza A disease and suggest the need for focused studies on viral tropism during pregnancy to better understand the proximate cause for the observed immunopathology.

Association between social vulnerability and influenza and tetanus-diphtheria-acellular pertussis vaccination in pregnant and postpartum individuals

BACKGROUND

Despite current guidelines recommending universal vaccination, the frequency of vaccination in pregnancy for influenza and tetanus-diphtheria-acellular pertussis remains low.

OBJECTIVE

This study aimed to evaluate the association between community-level social vulnerability and influenza and anticipated tetanus-diphtheria-acellular pertussis vaccinations among pregnant and postpartum individuals.

STUDY DESIGN

We conducted a cross-sectional survey of vaccine hesitancy in the peripartum period among pregnant and postpartum participants enrolled in prenatal care at a single tertiary care center from March 22, 2021, to April 02, 2021. Participant addresses were geocoded using ArcGIS and linked at the census tract level. The primary exposure was community-level social vulnerability as measured by the US Centers for Disease Control and Prevention's Social Vulnerability Index. This index incorporates 15 census variables to produce a composite score and subscores across 4 major thematic domains (socioeconomic status, household composition and disability, minority status and language, and housing type and transportation). The scores range from 0 to 1, with higher values indicating greater social vulnerability. The primary outcomes were self-reported influenza vaccination during the current influenza season and having received or planning to receive the tetanus-diphtheria-acellular pertussis vaccination in pregnancy. We used multivariable logistic regression and adjusted for age, self-reported race and ethnicity, parity, trimester of pregnancy, and chronic comorbid conditions.

RESULTS

Of 456 assessed individuals (95% pregnant individuals and 5% postpartum individuals), the frequency of influenza vaccination was 58% (95% confidence interval, 53-62), and the anticipated tetanus-diphtheria-acellular pertussis vaccination was 72% (95% confidence interval, 68-76). Individuals from communities with a higher Social Vulnerability Index were less likely to report vaccination in pregnancy than those from communities with a lower Social Vulnerability Index. Specifically, for each 0.1-unit increase in the Social Vulnerability Index, the odds of influenza vaccination (adjusted odds ratio, 0.23; 95% confidence interval, 0.11-0.46) and anticipated tetanus-diphtheria-acellular pertussis vaccination (adjusted odds ratio, 0.24; 95% confidence interval, 0.11-0.53) decreased by >70%. By domain, the Social Vulnerability Index subscores of socioeconomic status (influenza adjusted odds ratio, 0.20 [95% confidence interval, 0.10-0.40]; tetanus-diphtheria-acellular pertussis adjusted odds ratio, 0.25 [95% confidence interval, 0.12-0.53]) and housing type and transportation (influenza adjusted odds ratio, 0.41 [95% confidence interval, 0.19-0.84; tetanus-diphtheria-acellular pertussis adjusted odds ratio, 0.39 [95% confidence interval, 0.18-0.87) were inversely associated with a lower odds of influenza and tetanus-diphtheria-acellular pertussis vaccinations.

CONCLUSION

Pregnant and postpartum individuals living in areas with higher social vulnerability were less likely to report influenza and anticipated tetanus-diphtheria-acellular pertussis vaccinations in pregnancy. The Social Vulnerability Index could be used as a tool to improve vaccine equity and address disparities in vaccination in pregnancy.

Pregnant Women's Knowledge of and Attitudes towards Influenza Vaccination during the COVID-19 Pandemic in Poland

Pregnant women are more susceptible to influenza virus infections due to the immunological and physiological changes in the course of pregnancy. Vaccination during pregnancy is a safe and effective method for protecting both the mothers and the infants from influenza and its complications. This study was conducted in order to determine the knowledge and attitudes of Polish pregnant women towards influenza vaccination during the COVID-19 pandemic. A questionnaire-based and self-administered study was carried out fully online and a total of 515 women participated. A total of 52% (n = 268) of surveyed women answered that vaccination against influenza during pregnancy was safe. However, only 21% (n = 108) were vaccinated against influenza during their current pregnancy and 17.5% (n = 90) intended to be vaccinated. The participants indicated many concerns about getting vaccinated during pregnancy, but also many benefits that come with the vaccination. General knowledge about influenza, its complications, and vaccination was quite high in the study group.