S1  Search  Covidex [114]  University of Waterloo and NYU  https://covidex.ai/  CORD-19, ClinicalTrials.gov through TrialStreamer  Retrieves passages using Anserini [109]. Reranking using T5-base model [72] finetuned on biomedical text and trained for ranking on MS MARCO [14].  Supports user-written keyphrase queries. Highlights matched terms in abstract. Toggle for searching different corpora.