{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T06:33:48Z","timestamp":1783492428189,"version":"3.55.0"},"reference-count":55,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2022,3,22]],"date-time":"2022-03-22T00:00:00Z","timestamp":1647907200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J Intern Med"],"published-print":{"date-parts":[[2022,7]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Severe acute respiratory syndrome coronavirus (SARS\u2010CoV)\u20102 has spread worldwide, leading the World Health Organization (WHO) to declare a pandemic, on 11 March 2020. Variants of concern have appeared at regular intervals\u2014Alpha, Beta, Gamma, Delta, and now Omicron. Omicron variant, first identified in Botswana in November 2021, is rapidly becoming the dominant circulating variant. In this review, we provide an overview regarding the molecular profile of the Omicron variant, epidemiology, transmissibility, the impact on vaccines, as well as vaccine escape, and finally, we report the pharmacological agents able to block the endocellular entry of SARS\u2010CoV\u20102 or to inhibit its viral replication. The Omicron has more than 50 mutations, of which the spike protein has 26\u201335 amino acids different from the original SARS\u2010CoV\u20102 virus or the Delta, some of which are associated with humoral immune escape potential and greater transmissibility. Omicron has a significant growth advantage over Delta, leading to rapid spread with higher incidence levels. The disease so far has been mild compared to the Delta. The two vaccination doses offer little or no protection against Omicron infection while the booster doses provide significant protection against mild illness and likely offer even greater levels of protection against serious illness. Recently, new oral antiviral agents such as molnupiravir and paxlovid have been approved and represent important therapeutic alternatives to antiviral remdesivir. In addition, monoclonal antibodies such as casirivimab\/imdevimab bind different epitopes of the spike protein receptor; is this class of drugs effective against the Omicron variant? However, more research is needed to define whether Omicron is indeed more infectious and whether the vaccines, monoclonal antibodies, and antivirals currently available are effective.<\/jats:p>","DOI":"10.1111\/joim.13478","type":"journal-article","created":{"date-parts":[[2022,3,15]],"date-time":"2022-03-15T10:49:10Z","timestamp":1647341350000},"page":"81-90","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":131,"title":["Advances in the Omicron variant development"],"prefix":"10.1111","volume":"292","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2623-166X","authenticated-orcid":false,"given":"Antonio","family":"Vitiello","sequence":"first","affiliation":[{"name":"Pharmaceutical Department Usl Umbria 1  Perugia Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9298-6783","authenticated-orcid":false,"given":"Francesco","family":"Ferrara","sequence":"additional","affiliation":[{"name":"Pharmaceutical Department Asl Napoli 3 Sud  Naples Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amogh M.","family":"Auti","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine University of Campania \u201cLuigi Vanvitelli\u201d  Naples Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6201-4200","authenticated-orcid":false,"given":"Marina","family":"Di Domenico","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine University of Campania \u201cLuigi Vanvitelli\u201d  Naples Italy"},{"name":"Department of Biology College of Science and Technology Temple University  Philadelphia Pennsylvania USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6989-010X","authenticated-orcid":false,"given":"Mariarosaria","family":"Boccellino","sequence":"additional","affiliation":[{"name":"Department of Precision Medicine University of Campania \u201cLuigi Vanvitelli\u201d  Naples Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,3,22]]},"reference":[{"key":"e_1_2_10_2_1","unstructured":"World Health Organization.WHO Director\u2010General's opening remarks at the media briefing on COVID\u201019 11 March 2020.https:\/\/www.who.int\/"},{"key":"e_1_2_10_3_1","unstructured":"Johns Hopkins University.New cases of COVID\u201019 in world countries. 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