{"doi":"10.1101/2021.10.02.462862","title":"<i>In Vitro</i> Activity of Cysteamine Against SARS-CoV-2 Variants","abstract":"Abstract Global COVID-19 pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Continuous emergence of new variants and their rapid spread are jeopardizing vaccine countermeasures to a significant extent. While currently available vaccines are effective at preventing illness associated with SARS-CoV-2 infection, these have been shown to be less effective at preventing breakthrough infection and transmission from a vaccinated individual to others. Here we demonstrate broad antiviral activity of cysteamine HCl in vitro against major emergent infectious variants of SARS-CoV-2 in a highly permissible Vero cell line. Cysteamine HCl inhibited infection of wild type, alpha, beta, gamma, delta, lambda, and omicron variants effectively. Cysteamine is a very well-tolerated US FDA-approved drug used chronically as a topical ophthalmic solution to treat ocular cystinosis in patients who receive it hourly or QID lifelong at concentrations 6 to 10 times higher than that required to completely inhibit SARS CoV-2 in tissue culture. Application of cysteamine as a topical nasal treatment can potentially1) mitigate existing infection 2) prevent infection in exposed individuals, and 3) limit the contagion in vulnerable populations.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":221752,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9518,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":822931,"name":"Robert F Gavin","orcid":null,"position":1,"is_corresponding":false},{"id":822250,"name":"Aaron Towne","orcid":"0000-0002-7315-5375","position":2,"is_corresponding":false},{"id":711933,"name":"Lauren Wattay","orcid":"0000-0001-9951-7162","position":3,"is_corresponding":false},{"id":822932,"name":"Maria Grazia Ferrari","orcid":null,"position":4,"is_corresponding":false},{"id":398796,"name":"Ranajit Pal","orcid":null,"position":5,"is_corresponding":false},{"id":822249,"name":"Jess G. Thoene","orcid":"0000-0002-0446-4756","position":0,"is_corresponding":true}],"reference_count":36,"raw_metadata":null,"created_at":"2026-07-18T23:53:59.302331Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}