https://www.selleckchem.com/products/az-3146.html This protocol describes an indirect enzyme-linked immunosorbent assay for qualitative detection of IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Syrian hamster serum samples. We describe the preparation of inactivated virus antigens and the negative control antigen and the use of antigen-coated microtiter plates to detect SARS-CoV-2-specific antibodies from SARS-CoV-2-infected hamsters, including the criteria for differentiating positive versus negative reaction. The limited batch-to-batch variability of this assay has been verified with two batches of independently prepared antigens. For complete details on the use and execution of this protocol, please refer to Mohandas et al. (2021). Early in the pandemic it was suggested that pre-existing use of non-steroidal anti-inflammatory drugs (NSAIDs) could lead to increased disease severity in patients with COVID-19. NSAIDs are an important analgesic, particularly in those with rheumatological disease, and are widely available to the general public without prescription. Evidence from community studies, administrative data, and small studies of hospitalised patients suggest NSAIDs are not associated with poorer COVID-19 outcomes. We aimed to characterise the safety of NSAIDs and identify whether pre-existing NSAID use was associated with increased severity of COVID-19 disease. This prospective, multicentre cohort study included patients of any age admitted to hospital with a confirmed or highly suspected SARS-CoV-2 infection leading to COVID-19 between Jan 17 and Aug 10, 2020. The primary outcome was in-hospital mortality, and secondary outcomes were disease severity at presentation, admission to critical care, receipt of invasive ventilation,riables, NSAID use was not associated with worse in-hospital mortality (matched OR 0·95, 95% CI 0·84-1·07; p=0·35), critical care admission (1·01, 0·87-1·17; p=0·89), requirement for invasive v