Hippo Signaling Pathway Activation during SARS-CoV-2 Infection Contributes to Host Antiviral Response (preprint)

SARS-CoV-2, responsible for the COVID-19 pandemic, causes respiratory failure and damage to multiple organ systems. The emergence of viral variants poses a risk of vaccine failures and prolongation of the pandemic. However, our understanding of the molecular basis of SARS-CoV-2 infection and subsequent COVID-19 pathophysiology is limited. In this study, we have uncovered a critical role for the evolutionarily conserved Hippo signaling pathway in COVID-19 pathogenesis. Given the complexity of COVID-19 associated cell injury and immunopathogenesis processes, we investigated Hippo pathway dynamics in SARS-CoV-2 infection by utilizing COVID-19 lung samples, and human cell models based on pluripotent stem cell-derived cardiomyocytes (PSC-CMs) and human primary lung air-liquid interface (ALI) cultures. SARS-CoV-2 infection caused activation of the Hippo signaling pathway in COVID-19 lung and in vitro cultures. Both parental and Delta variant of concern (VOC) strains induced Hippo pathway. The chemical inhibition and gene knockdown of upstream kinases MST1/2 and LATS1 resulted in significantly enhanced SARS-CoV-2 replication, indicating antiviral roles. Verteporfin a pharmacological inhibitor of the Hippo pathway downstream transactivator, YAP, significantly reduced virus replication. These results delineate a direct antiviral role for Hippo signaling in SARS-CoV-2 infection and the potential for this pathway to be pharmacologically targeted to treat COVID-19.

Out of Season Influenza during a COVID-19 Void in the State of Rio de Janeiro, Brazil: Temperature Matters. (preprint)

An out-of-season opportunistic H3N2 type A influenza epidemic occurred in the state of Rio de Janeiro, Brazil during October-November 2021, in between the Delta and Omicron SARS CoV-2 surges. We assessed the contribution of climate change and influenza immunization coverage in this unique, little publicized phenomenon. State weather patterns during the influenza epidemic were significantly different from the five preceding years, matching typical winter temperatures. There was also a mismatch between influenza vaccine strains used in the winter of 2021 (trivalent vaccine with two type A strains (Victoria/2570/2019 H1N1, Hong Kong/2671/2019 H3N2) and one type B strain (Washington/02/2019, wild-type) and the circulating influenza strain responsible for the epidemic (H3N2 Darwin type A influenza strain). In addition, in 2021 there was poor influenza vaccine coverage with only 56% of adults immunized. Amid the COVID-19 pandemic, we should be prepared for out-of-season outbreaks of other respiratory viruses in periods of COVID-19 remission. The availability of year-round influenza vaccines could help avoid unnecessary morbidity and mortality given that antibodies rapidly wane. Moreover, this would enable unimmunized individuals to have additional opportunity to vaccinate during out of season outbreaks.

Maternal Outcomes and Risk Factors for Severity Among Pregnant Women With COVID-19: A Case Control Study From the COVI-Preg International Registry (preprint)

Background: Recent evidence suggests that pregnant women might be at higher risk of severe disease associated with the emerging pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while exposed fetuses/newborns could suffer from preterm birth, growth restriction and neonatal infections. The magnitude of this increased risk and specific risk factors for severity remains unclear.Methods: We performed a case control study comparing pregnant women with severe coronavirus disease 19 (case) to pregnant women with a milder form (controls) enrolled in COVI-Preg international registry cohort between from March 24 to July 26, 2020. Risk factors for severity, obstetrical, fetal and neonatal outcomes were assessed.Findings: A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented a severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of cesarean sections [70.7% (n=53/75)], preterm deliveries [62.7% (n= 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n=31/75)].Interpretation: Pregnant women, particularly those with associated comorbidities, seem to be at higher risk of severe complications of SARS-CoV-2 infection. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease; complications include cesarean sections, prematurity and neonatal admission to the intensive care unit.Funding Statement: None.Declaration of Interests: The authors declare that they have no conflicts of interest.Ethics Approval Statement: The study was approved by both the Swiss Ethical Board (CER-VD- 2020-00548) and the local ethics boards at each participating center.

Maternal and Obstetrical Outcomes in a Cohort of Pregnant Women Tested for SARS-CoV-2: Interim Results of the COVI-Preg International Registry (preprint)

Background: Pregnant women represent a vulnerable population at higher risk of complications of infectious diseases. Data regarding the consequences of the emerging pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy are scarce. Recent evidence suggests that pregnant women might be at higher risk of severe disease, while exposed fetuses and newborns could suffer from preterm birth, growth restriction and neonatal infections.Methods: We developed an international web registry to allow structured data collection. Pregnant women at any stage during gestation tested for SARS-CoV-2 infection were enrolled. Maternal, obstetrical and neonatal outcomes were recorded.Findings: 1033 pregnant women tested for SARS-CoV-2 were included, among which 926 tested positive and 107 tested negative. Positive pregnant women were at higher risk of severe maternal outcomes compared to negative women [aRR 5.6, 95% CI 1.4-22.7]. Risk factors for severe maternal outcomes among positive women were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. No difference in term of obstetrical and neonatal outcomes were observed between positive and negative women. Positive pregnant women with severe maternal outcomes were at higher risk of cesarean sections [70.7% (n=53/75)], preterm deliveries [62.7% (n= 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n=31/75)]. A positive neonatal SARS-CoV-2 test was observed in 2.9% (n=11/384) of newborns with an available test at birth.Interpretation: Pregnant women, particularly those with associated comorbidities, seem to be at higher risk of severe complications of SARS-CoV-2 infection. Preliminary data regarding obstetrical and neonatal outcomes among women with a mild disease are reassuring.Funding Statement: None.Declaration of Interests: The authors declare that we have no conflicts of interest.Ethics Approval Statement: The study was approved by both the Swiss Ethical Board (CER-VD-2020-00548) and the local ethics boards at each participating center.