Summary: Background: The novel coronavirus (CoV) severe acute respiratory syndrome (SARS)-CoV-2 outbreak started at the end of 2019 in Wuhan, China, and spread over 100 countries. SARS-CoV-2 uses the membrane protein Angiotensin I converting enzyme 2(ACE2) as a cell entry receptor. Indeed, it was reported that the balance of Renin-Angiotensin System (RAS), regulated by both ACE and ACE2, was altered in COVID-19 patients. It is controversial, however, whether commonly used anti-hypertensive drugs Angiotensin I converting enzyme inhibitor (ACEI) and Angiotensin II receptor blocker (ARB) shall be continued in the confirmed COVID-19 patients. This study was designed to investigate any difference in disease severity between COVID-19 patients with hypertension comorbidity. The included COVID-19 patients used ACEI, ARB, calcium channel blockers (CCB), beta blockers (BB), or thiazide to treat preexisting hypertension prior to the hospital were compared to patients who did not take any of those drugs. Methods: In this multicentre retrospective study, clinical data of 511 COVID-19 patients were analyzed. Patients were categorized into six sub-groups of hypertension comorbidity based on treatment using one of anti-hypertension drugs (ACEI, ARB, CCB, BB, thiazide), or none. A meta-analysis was performed to evaluate the use of ACEI and ARB associated with pneumonia using published studies. Findings: Among the elderly (age>65) COVID-19 patients with hypertension comorbidity, the risk of COVID-19-S (severe disease) was significantly decreased in patients who took ARB drugs prior to hospitalization compared to patients who took no drugs (OR=0·343, 95% CI 0·128-0·916, p=0·025). The meta-analysis showed that ARB use has positive effects associated with morbidity and mortality of pneumonia. Interpretation: Elderly (age>65) COVID-19 patients with hypertension comorbidity who are taking ARB anti-hypertension drugs may be less likely to develop severe lung disease compared to patients who take no anti-hypertension drugs. Funding: National Natural Science Foundation of China, Chinese Academy of Medical Sciences Research in context: Evidence before this study: We searched PubMed for articles published up to March 15, 2020 using keywords “2019-nCoV”, “SARS-CoV-2”, “novel coronavirus”, and COVID-19 AND “ARB”, and “angiotensin II receptor blocker” for papers published in both English and Chinese. We found three papers: one from our group, published in Science China Life Science that demonstrated an elevated Angiotensin II level in blood samples from COVID-19 patients; another a perspective article in Chinese recommending ACEI and ARBs as potential remedies for SARS-CoV-2 infections; the third a retrospective study in Chinese identifying no significant difference between ACEI/ARB associated with outcomes in 112 COVID-19 patients with CVD comorbidity. The International society of Hypertension stated on March 16 ^th , 2020: “there are no clinical data in human to show that ACE-inhibitors or ARBs either improve or worsen susceptibility to COVID-19 infection nor do they affect the outcomes of those infected”. Added value of this study: We retrospectively reviewed different types of anti-hypertensive drugs taken by COVID-19 patients with hypertension comorbidity prior to entering the hospital. We discovered that ARB hypertensive drugs were associated with a decreased risk of severe disease in elderly (age>65) COVID-19 patients (OR=0·343, 95% CI 0·128-0·916, p=0·025), the first evidence of ARBs association to COVID-19 infections in human. We conducted a meta-analysis in the literature and found that ARB has positive effects associated with morbidity and mortality of pneumonia. Implications of all the available evidence: ARB drugs are widely used in the population with hypertension. Treatments with ACEI and ARBs should be continuous according to medical guidelines. RCT trials of ARB associated with morbidity and mortality of SARS-CoV-2 infection are recommended in the future.

Influenza A virus (IAV) remains a major global health threat, and host-directed antivirals may help overcome rapid viral mutation and drug resistance. Here, we performed a genome-wide siRNA screen in A549 cells using cell viability as an integrated endpoint to identify host determinants of IAV (PR8/H1N1) infection. Using plate-normalized viability ratios, we identified 2134 genes with >40% viability change after infection (2048 UP and 86 DOWN; two-tailed t-test, n = 3; p < 0.05, FDR < 0.1). MetaCore pathway analysis showed enrichment of programs linked to host response and tissue injury control, including RAS-related signaling and multiple metabolic pathways such as estradiol, ubiquinone/mitochondrial redox, and benzo[a]pyrene/xenobiotic metabolism. DAVID Gene Ontology analysis further highlighted biological processes relevant to infection, including endocytosis, transcription, and translation, consistent with host pathways supporting viral replication. Benchmarking against meta-analyzed RNAi and CRISPR resources revealed that shared hits were enriched for translation, nucleocytoplasmic transport, and ER-Golgi trafficking, supporting external validity, whereas the large unique UP fraction was dominated by hormone metabolism, detoxification, and mitochondrial redox/CoQ pathways, consistent with viability-specific, tolerance-associated host response programs. Integrating the screen with DrugBank identified 174 druggable host genes corresponding to 345 candidate compounds. Together, these findings provide a systematic resource of host factors influencing H1N1 infection, improve understanding of influenza virus–host interactions, and offer a foundation for future development of host-directed antiviral strategies and drug repurposing efforts.