https://www.researchsquare.com/article/rs-1601788/v1 Research Square [ ] Browse Preprints COVID-19 Preprints Protocols Videos Journals Tools & Services Overview Digital Editing Professional Editing Badges Research Promotion Your Cart About Preprint Platform In Review Editorial Policies FAQ Our Team Advisory Board Blog Sign In Submit a Preprint Cite Share Download PDF Brief Communication SARS-CoV-2 Omicron Variant is as Deadly as Previous Waves After Adjusting for Vaccinations, Demographics, and Comorbidities Zachary Strasser, Aboozar Hadavand, Shawn Murphy, Hossein Estiri This is a preprint; it has not been peer reviewed by a journal. https://doi.org/10.21203/rs.3.rs-1601788/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Nature Portfolio Version 1 posted 02 May, 2022 You are reading this latest preprint version Abstract The B.1.1.529 (Omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has previously been reported as more transmissible, but less severe than other SARS-CoV-2 variants. To test this assumption, we linked state-level vaccination data with quality-controlled electronic health records from a large healthcare system, including 13 hospitals, in Massachusetts, USA. We then performed a weighted case-control study to compare risks of hospital admission and mortality across the SARS-CoV-2 waves in over 130,000 COVID patients. Although the unadjusted rates of hospital admission and mortality appeared to be higher in previous waves compared to the Omicron period, after adjusting for confounders including various demographics, Charlson comorbidity index scores, and vaccination status (and holding the healthcare utilization constant), we found that the risks of hospitalization and mortality were nearly identical between periods. Our analysis suggests that the intrinsic severity of the Omicron variant may be as severe as previous variants. Full Text Competing Interests There is NO Competing Interest. Cite Share Download PDF Status: Under Review Nature Portfolio Version 1 posted 02 May, 2022 You are reading this latest preprint version Research Square Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we're committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Twitter logoFacebook logoYouTube logoVimeo logoInstagram logoLinkedIn logo Also discoverable on ResearcherApp logo Platform About Our Team In Review Editorial Policies Advisory Board Contact Us Resources Author Services Blog Accessibility API Access RSS feed Company About Us Careers Partner With Us Responsibility Press [icon-subsc] Get Updates First Name [ ] Last Name [ ] Email [ ] Subscribe (c) Research Square 2022 | ISSN 2693-5015 (online) Privacy PolicyTerms of ServiceDo Not Sell My Personal Information