{"doi":"10.1101/2022.02.22.481491","title":"Molnupiravir (MK-4482) is efficacious against Omicron and other SARS-CoV-2 variants in the Syrian hamster COVID-19 model","abstract":"The recent emergence of the SARS-CoV-2 Omicron variant of concern (VOC) containing a heavily mutated spike protein capable of escaping preexisting immunity, identifies a continued need for interventional measures. Molnupiravir (MK-4482), an orally administered nucleoside analog, has demonstrated efficacy against earlier SARS-CoV-2 lineages and was recently approved for SARS-CoV-2 infections in high-risk adults. Here we assessed the efficacy of MK-4482 against the earlier Alpha, Beta and Delta VOCs and Omicron in the Syrian hamster COVID-19 model. Omicron replication and associated lung disease in vehicle treated hamsters was reduced compared to the earlier VOCs. MK-4482 treatment inhibited virus replication in the lungs of Alpha, Beta and Delta VOC infected hamsters. Importantly, MK-4482 profoundly inhibited virus replication in the upper and lower respiratory tract of hamsters infected with the Omicron VOC. Consistent with its mutagenic mechanism, MK-4482 treatment had a more pronounced inhibitory effect on infectious virus titers compared to viral RNA genome load. Histopathologic analysis showed that MK-4482 treatment caused a concomitant reduction in the level of lung disease and viral antigen load in infected hamsters across all VOCs examined. Together, our data indicate the potential of MK-4482 as an effective antiviral against known SARS-CoV-2 VOCs, especially Omicron, and likely future SARS-CoV-2 variants.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2022,"id":297866,"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":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9506,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":107174,"name":"Atsushi Okumura","orcid":"0000-0002-7779-3059","position":1,"is_corresponding":false},{"id":662279,"name":"Matthew Lewis","orcid":"0000-0002-6657-7588","position":2,"is_corresponding":false},{"id":107169,"name":"Friederike Feldmann","orcid":"0000-0002-1363-1077","position":3,"is_corresponding":false},{"id":107175,"name":"Kimberly Meade‐White","orcid":"0000-0003-0503-8174","position":4,"is_corresponding":false},{"id":867702,"name":"Forrest Bohler","orcid":"0000-0002-9963-2213","position":5,"is_corresponding":false},{"id":108448,"name":"Amanda M. Griffin","orcid":"0000-0002-5971-5954","position":6,"is_corresponding":false},{"id":107182,"name":"Rebecca Rosenke","orcid":"0000-0003-3779-7423","position":7,"is_corresponding":false},{"id":552057,"name":"Carl Shaia","orcid":"0000-0001-8907-8821","position":8,"is_corresponding":false},{"id":237976,"name":"Michael A. Jarvis","orcid":"0000-0002-0124-4061","position":9,"is_corresponding":false},{"id":107426,"name":"Heinz Feldmann","orcid":"0000-0001-9448-8227","position":10,"is_corresponding":false},{"id":237970,"name":"Kyle Rosenke","orcid":"0000-0001-8101-4348","position":0,"is_corresponding":true}],"reference_count":31,"raw_metadata":null,"created_at":"2026-07-19T00:31:31.270564Z","pmid":"35233571","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":[]}