The Effects of In Utero Exposure to Influenza on Birth and Infant Outcomes in the US

Evaluating Factors That Influence Influenza Vaccination Uptake among Pregnant People in a Medically Underserved Area in Washington State

INTRODUCTION

Despite substantial evidence demonstrating the effectiveness of influenza vaccines, only 38.6% of the adult United States population received an influenza vaccine during the 2023-2024 flu season. Vaccination rates are typically lower among U.S. minority groups, and in 2022, pregnant persons from U.S. minority racial and ethnic groups showed a decrease in influenza vaccine coverage.

METHODS

A survey was conducted with residents of Yakima County, Washington, which is home to one of the state's largest percentages of people who identify as Hispanic or Latino/a. The objective was to evaluate the uptake of influenza vaccine among pregnant persons. Surveys were sent to a random sample of 3000 residential mailing addresses. Of the 500 respondents, 244 (52.1%) reported that they had been pregnant, with those identifying as Hispanic or Latino/a constituting 23.8% of this total. Only 62 (26.2%) reported being immunized against influenza during pregnancy. Respondents who were immunized against influenza chose to be vaccinated to protect themselves from the flu (85.5%, n = 53); because a healthcare provider recommended getting vaccinated (85.5%, n = 53); to protect the baby from the flu (82.3%, n = 51); because it was available for free or low cost (62.9%, n = 39); and because vaccination was convenient (54.8%, n = 34). Qualitative evaluation identified that participants who were not vaccinated against influenza during pregnancy believed the vaccination was not needed, was not recommended by a healthcare provider, was difficult to access, they were against vaccination in general, or they were concerned about the safety and ingredients of the vaccine.

CONCLUSION

Barriers to vaccination identified in this study included vaccine distrust, lack of awareness, and concerns about vaccine efficacy and safety. Healthcare providers can help address these concerns by providing education and recommendations about the importance of influenza vaccination during pregnancy.

Maternal COVID-19 Serological Changes-Comparison between Seroconversion Rate in First and Third Trimesters of Pregnancy and Subsequent Obstetric Complications: A Cohort Study

Pregnant women are especially vulnerable to respiratory diseases. We aimed to study seroconversion rates during pregnancy in a cohort of consecutive pregnancies tested in the first and third trimesters and to compare the maternal and obstetric complications in the women who seroconverted in the first trimester and those who did so in the third. This was an observational cohort study carried out at the Hospital Universitario de Torrejón, in Madrid, Spain, during the first peak of the COVID-19 pandemic. All consecutive singleton pregnancies with a viable fetus attending their 11-13-week scan between 1 January and 15 May 2020 were included and seropositive women for SARS-CoV2 were monthly follow up until delivery. Antibodies against SARS-CoV-2 (IgA and IgG) were analyzed on stored serum samples obtained from first- and third-trimester routine antenatal bloods in 470 pregnant women. Antibodies against SARS-CoV-2 were detected in 31 (6.6%) women in the first trimester and in 66 (14.0%) in the third trimester, including 48 (10.2%) that were negative in the first trimester (seroconversion during pregnancy). Although the rate of infection was significantly higher in the third versus the first trimester (p = 0.003), no significant differences in maternal or obstetric complications were observed in women testing positive in the first versus the third trimester.

Vaccination, immunity, and the changing impact of COVID-19 on infant health

In utero exposure to COVID-19 infection may lead to large intergenerational health effects. The impact of infection exposure has likely evolved since the onset of the pandemic as new variants emerge, immunity from prior infection increases, vaccines become available, and vaccine hesitancy persists, such that when infection is experienced is as important as whether it is experienced. We examine the changing impact of COVID-19 infection on preterm birth and the moderating role of vaccination. We offer the first plausibly causal estimate of the impact of maternal COVID-19 infection by using population data with no selectivity, universal information on maternal COVID-19 infection, and linked sibling data. We then assess change in this impact from 2020 to 2023 and evaluate the protective role of COVID-19 vaccination on infant health. We find a substantial adverse effect of prenatal COVID-19 infection on the probability of preterm birth. The impact was large during the first 2 y of the pandemic but had fully disappeared by 2022. The harmful impact of COVID-19 infection disappeared almost a year earlier in zip codes with high vaccination rates, suggesting that vaccines might have prevented thousands of preterm births. The findings highlight the need to monitor the changing consequences of emerging infectious diseases over time and the importance of mitigation strategies to reduce the burden of infection on vulnerable populations.

Seasonal patterns in newborns' health: Quantifying the roles of climate, communicable disease, economic and social factors

Poor health at birth can have long-term consequences for children's development. This paper analyses an important factor associated with health at birth: the time of year that the baby is born, and hence seasonal risks they were exposed to in utero. There are multiple potential explanations for seasonality in newborns' health. Most previous research has examined these in isolation. We therefore do not know which explanations are most important - and hence which policy interventions would most effectively reduce the resulting early-life inequalities. In this paper, I use administrative data to estimate and compare the magnitudes of several seasonal risks, seeking to identify the most important drivers of seasonality in the Northern Territory of Australia, a large territory spanning tropical and arid climates and where newborn health varies dramatically with the seasons. I find that the most important explanations are heat exposure and disease prevalence. Seasonality in food prices and road accessibility have smaller effects on some outcomes. Seasonal fertility patterns, rainfall and humidity do not have statistically significant effects. I conclude that interventions that protect pregnant women from seasonal disease and heat exposure would likely improve newborn health in the Northern Territory, with potential long-term benefits for child development. It is likely that similar impacts would apply in other locations with tropical and arid climates, and that, without action, climate change will accentuate these risks.

The impact of trimester of COVID-19 infection on pregnancy outcomes after recovery

OBJECTIVES

Many physiological adaptations occur during pregnancy. It is not currently known how timing of COVID-19 infection impacts pregnancy. We hypothesize that maternal and neonatal outcomes are different if COVID-19 infection occurs in different trimesters of pregnancy.

METHODS

This retrospective cohort study was conducted from 3/2020 to 6/2022. Pregnant patients with a positive COVID-19 infection more than 10 days before delivery (COVID-recovered) were identified and grouped by trimester of infection. Demographics and maternal, obstetric, and neonatal outcomes were analyzed. ANOVA, Wilcoxon rank-sum test, Pearson's chi-squared test, and Fisher's exact test were used to compare continuous and categorical data.

RESULTS

A total of 298 COVID-recovered pregnant patients were identified. Of those, 48 (16 %) were infected in the 1st trimester, 123 (41 %) in the 2nd, and 127 (43 %) in the 3rd. There were no significant demographic differences between the study groups. Vaccination status was similar. Hospital admission rate and the need for oxygen therapy while infected were significantly higher in patients with 2nd or 3rd trimester infection (18 % & 20 % vs. 2 % and 13 % & 14 % vs. 0 %, respectively). Rates of preterm birth (PTB) and extreme PTB were higher in the 1st trimester infection group. Infants born to mothers infected in the 2nd trimester had more neonatal sepsis workups (22 % vs. 12 % & 7 %). Other outcomes were similar between groups.

CONCLUSIONS

First trimester COVID-recovered patients were more likely to have a preterm birth despite having lower rates of hospital admission and oxygen supplementation while infected than patients who recovered from a 2nd or 3rd trimester infection.

The relationship between COVID-19 vaccination status in pregnancy and birthweight

BACKGROUND

Despite findings that maternal COVID-19 infection in pregnancy is associated with low birthweight (weight of ≤2500 g), previous studies demonstrate no difference in low birthweight risk between COVID-19 vaccinated and unvaccinated pregnant persons. Few studies, however, have examined the association between unvaccinated, incomplete vaccination, and complete vaccination on low birthweight, and they have been limited by small sample sizes and lack of adjustment for covariates.

OBJECTIVE

We sought to address key limitations of prior work and evaluate this association between unvaccinated, incomplete, and complete COVID-19 vaccination status in pregnancy and low birthweight. We predicted a protective association of vaccination on low birthweight that varies by number of doses received.

STUDY DESIGN

We performed a population-based retrospective study using the Vizient clinical database, which included data from 192 hospitals in the United States. Our sample included pregnant persons who delivered between January 2021 and April 2022 at hospitals that reported maternal vaccination data and birthweight at delivery. Pregnant persons were categorized into 3 groups as follows: unvaccinated; incompletely vaccinated (1 dose of Pfizer or Moderna); or completely vaccinated (1 dose of Johnson & Johnson or ≥2 doses of Moderna or Pfizer). Demographics and outcomes were analyzed using standard statistical tests. We performed multivariable logistic regression to account for potential confounders between vaccination status and low birthweight in the original cohort. Propensity score matching was used to reduce bias related to the likelihood of vaccination, and the multivariable logistic regression model was then applied to the propensity score-matched cohort. Stratification analysis was performed for gestational age and race and ethnicity.

RESULTS

Of the 377,995 participants, 31,155 (8.2%) had low birthweight, and these participants were more likely to be unvaccinated than those without low birthweight (98.8% vs 98.5%, P<.001). Incompletely vaccinated pregnant persons were 13% less likely to have low birthweight neonates compared to unvaccinated persons (odds ratio, 0.87; 95% confidence interval, 0.73-1.04), and completely vaccinated persons were 21% less likely to have low birthweight neonates (odds ratio, 0.79; 95% confidence interval, 0.79-0.89). After controlling for maternal age, race or ethnicity, hypertension, pregestational diabetes, lupus, tobacco use, multifetal gestation, obesity, use of assisted reproductive technology, and maternal or neonatal COVID-19 infections in the original cohort, these associations remained significant for only complete vaccination (adjusted odds ratio, 0.80; 95% confidence interval, 0.70-0.91) and not incomplete vaccination (adjusted odds ratio, 0.87; 95% confidence interval, 0.71-1.04). In the propensity score-matched cohort, pregnant persons who were completely vaccinated against COVID-19 were 22% less likely to have low birthweight neonates compared to unvaccinated and incompletely vaccinated individuals (adjusted odds ratio, 0.78; 95% confidence interval, 0.76-0.79).

CONCLUSION

Pregnant persons who were completely vaccinated against COVID-19 were less likely to have low birthweight neonates compared to unvaccinated and incompletely vaccinated individuals. This novel association was observed among a large population after adjusting for confounders of low birthweight and factors influencing the likelihood of receiving the COVID-19 vaccine.

Health of neonates born in the maternity hospital in Bern, Switzerland, 1880-1900 and 1914-1922

The identification of factors impeding normal fetal development and growth is crucial for improving neonatal health. Historical studies are relevant because they show which parameters have influenced neonatal health in the past in order to better understand the present. We studied temporal changes of neonatal health outcomes (birth weight, gestational age, stillbirth rate) and the influence of different cofactors in two time periods. Moreover, we investigated particularly neonatal health in the wake of the 1918/19 influenza pandemic. Data were transcribed from the Bern Maternity Hospital and consists of two time periods: A) The years 1880, 1885, 1890, 1895 and 1900 (N = 1530, births' coverage 20%); B) The years 1914-1922 (N = 6924, births' coverage 40-50%). Linear regression models were used to estimate the effect of birth year on birth weight, and logistic regression models to estimate the effect of birth year and of the exposure to the pandemic on premature birth, stillborn and low birth weight (LBW). Mean birth weight increased only minimally between the two datasets; whereas, in the years 1914-1922, the preterm birth and stillbirth rates were markedly reduced compared with the years 1880-1900. Sex, parity, gestational age and maternal age were significantly associated with birth weight in both time periods. The probability of LBW was significantly increased in 1918 (OR 1.49 (95% CI 1.00-2.23)) and in 1919 (OR 1.55 (95% CI 1.02-2.36)) compared to 1914. Mothers who were heavily exposed to the influenza pandemic during pregnancy had a higher risk of stillbirth (OR 2.27 (95% CI 1.32-3.9)). This study demonstrated that factors influencing neonatal health are multifactorial but similar in both time periods. Moreover, the exposure to the 1918/19 pandemic was less associated with LBW and more associated with an increased risk of stillbirth. If this trend is confirmed by further studies, it could indicate some consistency across pandemics, as similar patterns have recently been shown for COVID-19.

[Prone position in the third trimester of pregnancy during the COVID-19 era: a transdisciplinary approach.]

There is very limited evidence regarding the use of prone position as part of the treatment of severe ARDS in pregnant patients. Currently, recommendations for invasive ventilatory management in this population are very scarce and are based on the extrapolation of conclusions obtained in studies of non-pregnant patients. The available literature asserts that the anatomy and physiology of the pregnant woman undergoes complex adaptive changes that must be considered during invasive ventilatory support and prone position. With prone ventilation, the benefits obtained for the couple far outweigh the eventual risks. Adequate programming of the mechanical ventilator correlates with a clear and simple concept: individualization of support. In any case, the decision on the timing of termination of pregnancy should be based on adequate multidisciplinary clinical judgment and should be supported by strict monitoring of the product.

Pregnancy outcomes after SARS-CoV-2 infection by trimester: A large, population-based cohort study

Objectives

Data regarding women infected with SARS-CoV-2 during early trimesters are scarce. We aimed to assess preterm birth (PTB) and small-for-gestational-age (SGA) rates in a large and unselected cohort by trimester at infection and overall.

Design

A retrospective cohort study including all women with a positive SARS-CoV-2 RT-PCR test during a non-ectopic singleton pregnancy between February 21^st 2020 and July 2^nd 2021 (N = 2753). Each infected woman was matched to a non-infected pregnant woman by age, last menstruation date, sector, and socioeconomic status.

Methods

Logistic regression was conducted to assess the risks of PTB and SGA including an interaction between group and trimester of infection. Multivariable models included underlying diseases, previous abortions and null parity. Subgroup analyses were conducted on symptomatic infected women and matched non-infected women.

Results

A total of 2753 /2789 (98.7%) eligible women that were infected during pregnancy could be matched, among them, 17.4% and 48.4% were infected during the first and third trimesters, respectively. While first and second trimester infections were not associated with PTB (p>0.8), third trimester infections and in particular after 34 weeks of gestation had a greater risk of PTB with adjusted ORs of 2.76 (95% CI 1.63–4.67) and 7.10 (95% CI 2.44–20.61), respectively. PTB risk was further heightened in symptomatic third trimester infections (OR = 4.28, 95% CI 1.94–9.25). SGA risk was comparable between study groups across all trimesters of infection. Pregnancy loss incidence was similar in both groups (adjusted OR = 1.16; 95% CI 0.90–1.50).

Conclusion

SARS-CoV-2 infection was associated with increased risk of PTB only among women infected during late pregnancy, particularly among symptomatic women.

Determinants of Place of Delivery during the COVID-19 Pandemic-Internet Survey in Polish Pregnant Women

Background and Objectives: COVID-19 is a pandemic disease, and its unpredictable outcome makes it particularly dangerous, especially for pregnant women. One of the decisions they have to make is where they will give birth. This study aimed to determine the factors influencing the choice of place of delivery and the impact of the COVID 19 pandemic on these factors. Materials and Methods: The study was conducted on 517 respondents from Poland. The research methods comprised the authors' own survey questionnaire distributed via the Internet from 8 to 23 June 2021. The survey was fully anonymous, voluntary, and addressed to women who gave birth during the pandemic or will give birth shortly. Results: A total of 440 (85.1%) respondents were afraid of SARS-CoV-2 infection. The most frequently indicated factors were fear of complications in the newborn, fear of intrauterine fetal death, and congenital disabilities in a newborn. A total of 74 (14.3%) women considered home delivery. The main factors that discouraged the choice of home birth were the lack of professional medical care 73.1% (N = 378), the lack of anesthesia 23.6% (N = 122), and the presence of indications for caesarean section 23.4% (N = 121). The possibility of mother-child isolation caused the greatest fear about hospital delivery. During the COVID-19 pandemic, pregnant women concerned about SARS-CoV-2 infection were more likely to consider home delivery than those without such fears. The most important factors affecting the choice of the place of delivery included the possibility of a partner's presence, excellent sanitary conditions and optimal distance from the hospital, and the availability of epidural analgesia for delivery. Conclusions: Our study identifies the determinants of place of delivery during the COVID-19 pandemic. The data we obtained can result in the healthcare system considering patients' needs in case of similar crisis in the future.

Comparing pregnancy outcomes between symptomatic and asymptomatic COVID-19 positive unvaccinated women- Multicenter study in Saudi Arabia

Introduction

COVID-19 infection in pregnancy ranges from asymptomatic infection to severe disease. However, the maternal and pregnancy outcomes are primarily favorable. Acute Respiratory Illness (ARI) score is a Visual Triage Checklist for Acute Respiratory symptoms created by the ministry of health of Saudi Arabia ¹² to screen the patient for acute respiratory infection with MERS-CoV. It has been used during the COVID-19 pandemic to identify suspected cases and place patients in isolation precautions if the score is≥ 4.

Method

This study is a cross-sectional study of all pregnant women who tested positive for COVID-19 in four medical centers located in four different cities in Saudi Arabia. The study period was from 1/3/2020 until 31/10/2020. Outcomes investigated were the prevalence of COVID infection in pregnant women at the time of delivery. Rate of asymptomatic disease, different maternal and pregnancy outcomes. Women were divided into symptomatic and asymptomatic groups according to the ARI score. The two groups were compared in maternal, perinatal, and neonatal outcomes. Furthermore, the cohort was divided according to maternal age into two groups: women of advanced maternal age ≥ 35 years and younger. The two groups were compared in maternal, perinatal, and neonatal outcomes

Results

During the study period, 9573 women gave birth at KAMCs, and 402 pregnant women were identified as COVID positive. Out of all COVID-positive women, only 394 women gave birth at KAMCs. The screening for COVID infection differed between the centers, but the testing was the same by the Nasopharyngeal polymerase chain reaction (PCR) swab. In Riyadh, screening was based on ARI scoring at the beginning of the pandemic. Then, it became universal. In Jeddah, the screening was based on ARI scoring. Any woman who scored four or more was labeled as suspected, and she was tested. Finally, in Madinah and Dammam, the screening was universal throughout the study.

The prevalence of COVID-19 infection among women who gave birth at KAMCs was 4.2% (402/9573). (CI 3.8–4.6%). At the time of diagnosis, most women (62%) were asymptomatic. The most common symptoms were cough and shortness of breath. Twenty-two women (5.5%) had Pneumonia, and five women (1.3%) needed admission to Intensive care units (ICU). One woman died due to respiratory failure.

When pregnancy outcomes were compared between symptomatic and asymptomatic women, pregnancy in symptomatic women was more likely to be complicated by Abortion (6 versus 2% p-value 0.00), fetal death (3 versus 1.3%), and cesarean delivery (30.8 versus 22.4%, p-value 0.001). COVID-positive pregnant women of advanced maternal age (AMA) were more likely to be symptomatic, have Abortion (5 versus 1%, p-value 0.01), and have Preterm delivery (17 versus 11% p-value 0.01) than younger women. In addition, neonatal death was more common in AMA COVID-positive women than younger (4 versus 0%), regardless of COVID-related symptoms.

Conclusion

Most of the COVID-infected pregnant women are asymptomatic. Therefore, the ARI scoring system does not help to triage patients. Symptomatic women, especially those older than 35, tend to have a higher maternal and pregnancy complication rate.

Does being infected with SARS-CoV-2 in the first-trimester increase the risk of miscarriage?

Aim of this study is to investigate whether the risk of miscarriage increases in pregnant women who had COVID-19 in first trimester. Our study included 52 patients with SARS-CoV-2 infection detected by RT-PCR and 53 patients with negative RT-PCR test in samples taken with nasopharyngeal swab in the first trimester between March 1 and December 31, 2020. Complete abortion, incomplete abortion, blighted ovum, intrauterine exitus, biochemical pregnancies were accepted as in the miscarriage group (MG). Pregnant women with COVID-19 and control group were compared in terms of demographic data, miscarriage rate and laboratory results. Patients were divided into MG and ongoing pregnancy groups (OPG) and compared in terms of the diagnosed weeks, clinical findings, laboratory results, treatments, and hospitalization. While miscarriage was observed in 15 (28.8%) of pregnant women infected with SARS-CoV-2 in the first trimester, this number was 7 (13.2%) in the control group. While the common symptoms in the MG were cough (60%), fever (53.3%), shortness of breath (53.3%), and fatigue (46.7%) (p<0.05); asymptomatic patients (51.4%) were higher in the OPG (p<0.001). Hospitalized patients were 33.3% in the MG and 8.1% in the OPG (p=0.02). According to the results of our study, the risk of miscarriage increases in pregnant women infected with SARS-CoV-2 (especially in severe infection) in the first trimester.

Effects of Vertical Transmission of Respiratory Viruses to the Offspring

Overt and subclinical maternal infections in pregnancy can have multiple and significant pathological consequences for the developing fetus, leading to acute perinatal complications and/or chronic disease throughout postnatal life. In this context, the current concept of pregnancy as a state of systemic immunosuppression seems oversimplified and outdated. Undoubtedly, in pregnancy the maternal immune system undergoes complex changes to establish and maintain tolerance to the fetus while still protecting from pathogens. In addition to downregulated maternal immunity, hormonal changes, and mechanical adaptation (e.g., restricted lung expansion) make the pregnant woman more susceptible to respiratory pathogens, such as influenza virus, respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Depending on the infectious agent and timing of the infection during gestation, fetal pathology can range from mild to severe, and even fatal. Influenza is associated with a higher risk of morbidity and mortality in pregnant women than in the general population, and, especially during the third trimester of pregnancy, mothers are at increased risk of hospitalization for acute cardiopulmonary illness, while their babies show higher risk of complications such as prematurity, respiratory and neurological illness, congenital anomalies, and admission to neonatal intensive care. RSV exposure in utero is associated with selective immune deficit, remodeling of cholinergic innervation in the developing respiratory tract, and abnormal airway smooth muscle contractility, which may predispose to postnatal airway inflammation and hyperreactivity, as well as development of chronic airway dysfunction in childhood. Although there is still limited evidence supporting the occurrence of vertical transmission of SARS-CoV-2, the high prevalence of prematurity among pregnant women infected by SARS-CoV-2 suggests this virus may alter immune responses at the maternal-fetal interface, affecting both the mother and her fetus. This review aims at summarizing the current evidence about the short- and long-term consequences of intrauterine exposure to influenza, RSV, and SARS-CoV-2 in terms of neonatal and pediatric outcomes.

The effect of maternal SARS-CoV-2 infection timing on birth outcomes: a retrospective multicentre cohort study

BACKGROUND

The impact of maternal SARS-CoV-2 infection remains unclear. In this study, we evaluated the risk of maternal SARS-CoV-2 infection on birth outcomes and how this is modulated by the pregnancy trimester in which the infection occurs. We also developed models to predict gestational age at delivery for people following a SARS-CoV-2 infection during pregnancy.

METHODS

We did a retrospective cohort study of the impact of maternal SARS-CoV-2 infection on birth outcomes. We used clinical data from Providence St Joseph Health electronic health records for pregnant people who delivered in the USA at the Providence, Swedish, or Kadlec sites in Alaska, California, Montana, Oregon, or Washington. The SARS-CoV-2 positive cohort included people who had a positive SARS-CoV-2 PCR-based test during pregnancy, subdivided by trimester of infection. No one in this cohort had been vaccinated for COVID-19 at time of infection. The SARS-CoV-2 negative cohort were people with at least one negative SARS-CoV-2 PCR-based test and no positive tests during pregnancy. Cohorts were matched on common covariates impacting birth outcomes, and univariate and multivariate analysis were done to investigate risk factors and predict outcomes. The primary outcome was gestational age at delivery with annotation of preterm birth classification. We trained multiple supervised learning models on 24 features of the SARS-CoV-2 positive cohort to evaluate performance and feature importance for each model and discuss the impact of SARS-CoV-2 infection on gestational age at delivery.

FINDINGS

Between March 5, 2020, and July 4, 2021, 73 666 pregnant people delivered, 18 335 of whom had at least one SARS-CoV-2 test during pregnancy before Feb 14, 2021. We observed 882 people infected with SARS-CoV-2 during their pregnancy (first trimester n=85; second trimester n=226; and third trimester n=571) and 19 769 people who have never tested positive for SARS-CoV-2 and received at least one negative SARS-CoV-2 test during their pregnancy. SARS-CoV-2 infection indicated an increased risk of preterm delivery (p<0·05) and stillbirth (p<0·05), accounted for primarily by first and second trimester SARS-CoV-2 infections. Gestational age at SARS-CoV-2 infection was correlated with gestational age at delivery (p<0·01) and had the greatest impact on predicting gestational age at delivery. The people in this study had mild or moderate SARS-CoV-2 infections and acute COVID-19 severity was not correlated with gestational age at delivery (p=0·31).

INTERPRETATION

These results suggest that pregnant people would benefit from increased monitoring and enhanced prenatal care after first or second trimester SARS-CoV-2 infection, regardless of acute COVID-19 severity.

FUNDING

US National Institutes of Health.

A M2 protein-based universal influenza vaccine containing Advax-SM adjuvant provides newborn protection via maternal or neonatal immunization

BACKGROUND

Despite newborns being at increased risk of serious influenza infection, influenza vaccines are currently not recommended for use in infants under 6 months of age. We therefore sought to evaluate the protective efficacy in mice of an M2-based influenza vaccine (CapM2e) formulated with Advax-SM adjuvant. Vaccine protection was assessed via both passive maternal immunization and direct neonatal immunization.

METHODS

For maternal transfer studies, female mice were immunized 1 week before and after mating. Blood was collected from both mother and offspring during weaning and pups were challenged when they reached 3 weeks of age with lethal doses of H1N1 and homologous reassortment influenza strain H3N2 with conserved M2. For direct immunization studies, newborns were immunized at 1 and 3 weeks of age and blood was collected prior to challenge at 4 weeks of age.

RESULTS

Maternal immunization with CapM2e + Advax-SM vaccine induced high maternal M2e antibody levels that were passively transferred to their offspring and provided them with protection against both H1N1 and H3N2 influenza strains when challenged at 3 weeks of age. When used for direct immunization of neonatal mice, CapM2e + Advax-SM vaccine similarly induced high serum M2e antibody levels and protected against H1N1 and H3N2 influenza challenges with protection associated with inhibition of virus replication with a significant reduction in lung virus load in immunized pups.

CONCLUSION

CapM2e + Advax-SM vaccine could be useful for protecting newborns against diverse influenza A strains, with opportunities to achieve protection by passive maternal immunization or active neonatal immunization. This data supports further development of this promising M2e-based vaccine candidate.

The Impact of Prenatal Exposure to Ramadan on Child Anthropomorphic Outcomes in Pakistan

OBJECTIVES

This study analyzes the intent-to-treat effect of prenatal exposure to Ramadan (the Islamic month of fasting) on outcomes including stunting and underweight for children under age 5 years in Pakistan born between 2003 and 2018.

METHODS

The study uses observational data from four rounds of the UN-supported Multiple Indicator Cluster Survey (MICS) data collected on 204,186 children under-5 from Punjab, Pakistan in 2007-2008, 2010-2011, 2013-2014, and 2017-2018. Excluding data on outliers and observations with incomplete data, multivariate logistic regression analysis was conducted on the appended cross-sectional data of 179,943 children under-5 to assess the risk of stunting or underweight according to the month of gestation coinciding with Ramadan.

RESULTS

We observe a significant increase in the risk of stunting and underweight associated with exposure to Ramadan following an inverted-U pattern. The peak impact of Ramadan exposure on a child being underweight occurs in the third month of pregnancy, where the probability of being underweight is 20 percent higher as compared to children whose gestation did not coincide with Ramadan. The peak impact of Ramadan exposure on stunting occurs in the fourth month of pregnancy, where the probability of stunting is 22 percent higher as compared to children whose gestation did not coincide with Ramadan. These results vary little by gender. In contrast, exposure to Ramadan in the ninth month of gestation is associated with a reduction in the risk of stunting for boys and underweight for both boys and girls.

CONCLUSIONS FOR PRACTICE

Our analysis indicates that prenatal exposure to Ramadan during the first two trimesters have negative implications for children's growth. The study highlights the critical role of maternal habits during early pregnancy, especially nutritional intake, for the long-term physical development of children.

Pregnancy and COVID-19

There are many unknowns for pregnant women during the coronavirus disease 2019 (COVID-19) pandemic. Clinical experience of pregnancies complicated with infection by other coronaviruses e.g., Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome, has led to pregnant woman being considered potentially vulnerable to severe SARS-CoV-2 infection. Physiological changes during pregnancy have a significant impact on the immune system, respiratory system, cardiovascular function, and coagulation. These may have positive or negative effects on COVID-19 disease progression. The impact of SARS-CoV-2 in pregnancy remains to be determined, and a concerted, global effort is required to determine the effects on implantation, fetal growth and development, labor, and neonatal health. Asymptomatic infection presents a further challenge regarding service provision, prevention, and management. Besides the direct impacts of the disease, a plethora of indirect consequences of the pandemic adversely affect maternal health, including reduced access to reproductive health services, increased mental health strain, and increased socioeconomic deprivation. In this review, we explore the current knowledge of COVID-19 in pregnancy and highlight areas for further research to minimize its impact for women and their children.

Building an interdisciplinary framework to advance conceptual and technical aspects of population-environment research focused on women's and children's health

Great gains have been made in providing researchers geo-spatial data that can be combined with population health data. This development is crucial given concerns over the human health outcomes associated with a changing climate. Merging population and environmental data remains both conceptually and technically challenging because of a large range of temporal and spatial scales. Here we propose a framework that addresses and advances both conceptual and technical aspects of population-environment research. This framework can be useful for considering how any time or space-based environmental occurrence influences population health outcomes and can be used to guide different data aggregation strategies. The primary consideration discussed here is how to properly model the space and time effects of environmental context on individual-level health outcomes, specifically maternal, child and reproductive health outcomes. The influx of geospatial health data and highly detailed environmental data, often at daily scales, provide an opportunity for population-environment researchers to move towards a more theoretically and analytically sound approach for studying environment and health linkages.