1918 Influenza Pandemic: In Utero Exposure in the United States and Long-Term Impact on Hospitalizations

What can we learn from historical pandemics? A systematic review of the literature

What are the insights from historical pandemics for policymaking today? We carry out a systematic review of the literature on the impact of pandemics that occurred since the Industrial Revolution and prior to Covid-19. Our literature searches were conducted between June 2020 and September 2023, with the final review encompassing 169 research papers selected for their relevance to understanding either the demographic or economic impact of pandemics. We include literature from across disciplines to maximise our knowledge base, finding many relevant articles in journals which would not normally be on the radar of social scientists. Our review identifies two gaps in the literature: (1) the need to study pandemics and their effects more collectively rather than looking at them in isolation; and (2) the need for more study of pandemics besides 1918 Spanish Influenza, especially milder pandemic episodes. These gaps are a consequence of academics working in silos, failing to draw on the skills and knowledge offered by other disciplines. Synthesising existing knowledge on pandemics in one place provides a basis upon which to identify the lessons in preparing for future catastrophic disease events.

Barriers to and solutions for representative inclusion across the lifespan and in life course research: The need for structural competency highlighted by the COVID-19 pandemic

Exclusion of special populations (older adults; pregnant women, children, and adolescents; individuals of lower socioeconomic status and/or who live in rural communities; people from racial and ethnic minority groups; individuals from sexual or gender minority groups; and individuals with disabilities) in research is a pervasive problem, despite efforts and policy changes by the National Institutes of Health and other organizations. These populations are adversely impacted by social determinants of health (SDOH) that reduce access and ability to participate in biomedical research. In March 2020, the Northwestern University Clinical and Translational Sciences Institute hosted the "Lifespan and Life Course Research: integrating strategies" "Un-Meeting" to discuss barriers and solutions to underrepresentation of special populations in biomedical research. The COVID-19 pandemic highlighted how exclusion of representative populations in research can increase health inequities. We applied findings of this meeting to perform a literature review of barriers and solutions to recruitment and retention of representative populations in research and to discuss how findings are important to research conducted during the ongoing COVID-19 pandemic. We highlight the role of SDOH, review barriers and solutions to underrepresentation, and discuss the importance of a structural competency framework to improve research participation and retention among special populations.

Dataset on social and psychological effects of COVID-19 pandemic in Turkey

This data was gathered to investigate how individuals' levels of intolerance to distress and instant anxiety are related to some of the behaviors that people can change in response to the COVID-19 pandemic. We present a dataset based on a four-wave survey of the social and psychological effects of the COVID-19 pandemic in Turkey (N = 2,817). Turkey was heavily impacted by the first waves of infections in 2020, and citizens were forced to adapt to governmental measures. So, the dataset provides unique opportunities to investigate the COVID-19 pandemic's role in shaping people's intolerance to distress and instant anxiety. The survey considered personal cleaning behavior, bank/credit card usage, online spending habits, individual security perception, and stockpile behavior. Furthermore, in this data, whether an individual or a household member was officially diagnosed with COVID-19 and socio-demographic indicators were determined. Hence, the resulting dataset can enable various analyses on social, psychological, perceived security, and self-rated health, influencing how individuals' levels of intolerance to distress and instant anxiety.

Social distancing and influenza mortality in 1918 did not increase suicide rates in the United States

Recent research has suggested that the social distancing mandates introduced in the United States during the main waves of the 1918-20 influenza pandemic caused an increase in suicide rates. However, that finding relies on poor-quality, temporally mismatched data and has signs of omitted variable bias. Similarly, a long-standing finding that American suicide rates in 1918-20 were also boosted by the influenza mortality of the time has gone unquestioned in the literature, despite the original research admitting its risk of ecological fallacy. Using higher-powered mortality data, I cast doubt on both findings by analyzing the experiences of the pandemic in 43 of the largest American cities of the time. In line with some populations' experiences of COVID-19, I report tentative evidence that social distancing mandates during the 1918-20 pandemic may have been associated with decreased suicide rates. Larger, cross-national investigations of the effects of historical pandemics and social distancing mandates on mental health and suicide are needed.

The legacy of maternal SARS-CoV-2 infection on the immunology of the neonate

Despite extensive studies into severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the effect of maternal infection on the neonate is unclear. To investigate this, we characterized the immunology of neonates born to mothers with confirmed SARS-CoV-2 infection during pregnancy. Here we show that maternal SARS-CoV-2 infection affects the neonatal immune system. Despite similar proportions of B cells, CD4⁺ T cells and CD8⁺ T cells, increased percentages of natural killer cells, Vδ2⁺ γδ T cells and regulatory T cells were detected in neonates born to mothers with recent or ongoing infection compared with those born to recovered or uninfected mothers. Increased plasma cytokine levels were also evident in neonates and mothers within the recent or ongoing infection group. Cytokine functionality was enhanced in neonates born to SARS-CoV-2-exposed mothers, compared to those born to uninfected mothers. In most neonates, this immune imprinting was nonspecific, suggesting vertical transmission of SARS-CoV-2 is limited, a finding supported by a lack of SARS-CoV-2-specific IgM in neonates despite maternal IgG transfer.

Behavioral responses to the 2015 MERS epidemic in Korea

Understanding behavioral responses to epidemics is important in evaluating the broad health consequences of emerging infectious diseases. Building on the economic epidemiology literature, this study investigates individual behavioral responses to the 2015 Middle East Respiratory Syndrome Coronavirus (MERS-CoV) epidemic in Korea using a panel of individuals in a nationally representative survey. Results show that exposure to the epidemic led to lasting impacts on smoking and drinking behaviors, indicating that emerging infectious disease outbreaks are motivations for behavioral changes and opportunities for public policy interventions. In particular, individuals in the hardest-hit regions or socially connected persons were more likely to change their risky behaviors, suggesting that intensity of exposure and social interactions are potential mechanisms.

Maternal-Fetal Inflammation in the Placenta and the Developmental Origins of Health and Disease

Events in fetal life impact long-term health outcomes. The placenta is the first organ to form and is the site of juxtaposition between the maternal and fetal circulations. Most diseases of pregnancy are caused by, impact, or are reflected in the placenta. The purpose of this review is to describe the main inflammatory processes in the placenta, discuss their immunology, and relate their short- and long-term disease associations. Acute placental inflammation (API), including maternal and fetal inflammatory responses corresponds to the clinical diagnosis of chorioamnionitis and is associated with respiratory and neurodevelopmental diseases. The chronic placental inflammatory pathologies (CPI), include chronic villitis of unknown etiology, chronic deciduitis, chronic chorionitis, eosinophilic T-cell vasculitis, and chronic histiocytic intervillositis. These diseases are less-well studied, but have complex immunology and show mechanistic impacts on the fetal immune system. Overall, much work remains to be done in describing the long-term impacts of placental inflammation on offspring health.