{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T09:21:30Z","timestamp":1768555290542,"version":"3.49.0"},"posted":{"date-parts":[[2022,7,28]]},"group-title":"Epidemiology","reference-count":14,"publisher":"openRxiv","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2022,7,28]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>The SARS-CoV-2 omicron BA.5 subvariant is progressively displacing earlier subvariants, BA.1 and BA.2, in many countries. One possible explanation is the ability of BA.5 to evade immune responses elicited by prior BA.1 and BA.2 infections. The impact of BA.1 infection on the risk of reinfection with BA.5 is a critical issue because adapted vaccines under current clinical development are based on BA.1.<\/jats:p>\n                <jats:p>We used the national Portuguese COVID-19 registry to analyze the risk of BA.5 infection in individuals without a documented infection or previously infected during periods of distinct variants\u2019 predominance (Wuhan-Hu-1, alpha, delta, BA.1\/BA.2). National predominance periods were established according to the national SARS-CoV-2 genetic surveillance data (when one variant represented &gt;90% of the sample isolates).<\/jats:p>\n                <jats:p>We found that prior SARS-CoV-2 infection reduced the risk for BA.5 infection. The protection effectiveness, related to the uninfected group, for a first infection with Wuhan-Hu-1 was 52.9% (95% CI, 51.9 \u2013 53.9%), for Alpha 54.9% (51.2 \u2013 58.3%), for Delta 62.3% (61.4 \u2013 63.3%), and for BA.1\/BA.2 80.0% (79.7 \u2013 80.2%).<\/jats:p>\n                <jats:p>The results ought to be interpreted in the context of breakthrough infections within a population with a very high vaccine coverage (&gt;98% of the study population completed the primary vaccination series).<\/jats:p>\n                <jats:p>In conclusion, infection with BA.1\/BA.2 reduces the risk for breakthrough infections with BA.5 in a highly vaccinated population. This finding is critical to appraise the current epidemiological situation and the development of adapted vaccines.<\/jats:p>","DOI":"10.1101\/2022.07.27.22277602","type":"posted-content","created":{"date-parts":[[2022,7,28]],"date-time":"2022-07-28T17:50:47Z","timestamp":1659030647000},"source":"Crossref","is-referenced-by-count":10,"title":["Risk of BA.5 infection in individuals exposed to prior SARS-CoV-2 variants"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4389-1483","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Malato","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3988-8241","authenticated-orcid":false,"given":"Ruy M.","family":"Ribeiro","sequence":"additional","affiliation":[]},{"given":"Pedro Pinto","family":"Leite","sequence":"additional","affiliation":[]},{"given":"Pedro","family":"Casaca","sequence":"additional","affiliation":[]},{"given":"Eug\u00e9nia","family":"Fernandes","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1855-0425","authenticated-orcid":false,"given":"Carlos","family":"Antunes","sequence":"additional","affiliation":[]},{"given":"V\u00e1lter R.","family":"Fonseca","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2679-0974","authenticated-orcid":false,"given":"Manuel Carmo","family":"Gomes","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6935-8500","authenticated-orcid":false,"given":"Luis","family":"Graca","sequence":"additional","affiliation":[]}],"member":"54368","reference":[{"key":"2022073002350784000_2022.07.27.22277602v1.1","doi-asserted-by":"crossref","unstructured":"Arora P , Kempf A , Nehlmeier I , et al. Augmented neutralisation resistance of emerging omicron subvariants BA.2.12.1, BA.4, and BA.5. The Lancet Infectious Diseases 2022;S1473309922004224.","DOI":"10.1016\/S1473-3099(22)00422-4"},{"key":"2022073002350784000_2022.07.27.22277602v1.2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMc2206725"},{"issue":"16","key":"2022073002350784000_2022.07.27.22277602v1.3","doi-asserted-by":"crossref","first-page":"1579","DOI":"10.1056\/NEJMc2201849","article-title":"Neutralization of the SARS-CoV-2 Omicron BA.1 and BA.2 Variants","volume":"386","year":"2022","journal-title":"N Engl J Med"},{"key":"2022073002350784000_2022.07.27.22277602v1.4","unstructured":"Cao Y , Yisimayi A , Jian F , et al. BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection. Nature [Internet] 2022 [cited 2022 Jul 12];Available from: https:\/\/www.nature.com\/articles\/s41586-022-04980-y"},{"key":"2022073002350784000_2022.07.27.22277602v1.5","unstructured":"National Institute of Health (INSA) Dr. Ricardo Jorge. Genetic diversity of the novel coronavirus SARS-CoV-2 (COVID-19) in Portugal. Lisbon: INSA; 2022. [Accessed 10 Jul 2022]. Available from: https:\/\/insaflu.insa.pt\/covid19."},{"key":"2022073002350784000_2022.07.27.22277602v1.6","doi-asserted-by":"crossref","unstructured":"Altarawneh HN , Chemaitelly H , Ayoub HH , et al. Protection of SARS-CoV-2 natural infection against reinfection with the Omicron BA.4 or BA.5 subvariants [Internet]. Epidemiology; 2022 [cited 2022 Jul 24]. Available from: http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2022.07.11.22277448","DOI":"10.1101\/2022.07.11.22277448"},{"key":"2022073002350784000_2022.07.27.22277602v1.7","doi-asserted-by":"crossref","unstructured":"Ayoub HH , Tomy M , Chemaitelly H , et al. Estimating protection afforded by prior infection in preventing reinfection: Applying the test-negative study design [Internet]. Epidemiology; 2022 [cited 2022 Jul 25]. Available from: http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2022.01.02.22268622","DOI":"10.1101\/2022.01.02.22268622"},{"key":"2022073002350784000_2022.07.27.22277602v1.8","unstructured":"Forecasting Team C-19, Lim SS. Past SARS-CoV-2 Infection Protection Against Reinfection: A Systematic Review and Meta-Analysis [Internet]. 2022 [cited 2022 Jul 25];Available from: https:\/\/papers.ssrn.com\/abstract=4155225"},{"key":"2022073002350784000_2022.07.27.22277602v1.9","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMOA2114583"},{"key":"2022073002350784000_2022.07.27.22277602v1.10","doi-asserted-by":"crossref","unstructured":"Chemaitelly H , Nagelkerke N , Ayoub HH , et al. Duration of immune protection of SARS-CoV-2 natural infection against reinfection in Qatar [Internet]. Epidemiology; 2022 [cited 2022 Jul 25]. Available from: http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2022.07.06.22277306","DOI":"10.1101\/2022.07.06.22277306"},{"key":"2022073002350784000_2022.07.27.22277602v1.11","doi-asserted-by":"crossref","unstructured":"Chemaitelly H , Ayoub HH , Coyle P , et al. Protection of Omicron sub-lineage infection against reinfection with another Omicron sub-lineage [Internet]. Epidemiology; 2022 [cited 2022 Jul 25]. Available from: http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2022.02.24.22271440","DOI":"10.1101\/2022.02.24.22271440"},{"key":"2022073002350784000_2022.07.27.22277602v1.12","unstructured":"National Institute of Health (INSA) Dr. Ricardo Jorge. National COVID-19 Serologic Survey in Portugal. Lisbon: INSA; 2021. [Accessed 24 Jul 2022]. Available from: http:\/\/repositorio.insa.pt\/bitstream\/10400.18\/7828\/1\/ISN_COVID-19_relat\u00f3rio_3F_final.pdf."},{"key":"2022073002350784000_2022.07.27.22277602v1.13","unstructured":"Statistics Portugal. 2022. Available at https:\/\/www.ine.pt\/."},{"key":"2022073002350784000_2022.07.27.22277602v1.14","unstructured":"World Health Organization. Public health surveillance for COVID-19: interim guidance. WHO\/2019-nCoV\/SurveillanceGuidance\/2022.2. Obtained at https:\/\/www.who.int\/publications\/i\/item\/WHO-2019-nCoV-SurveillanceGuidance-2022.1."}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1101\/2022.07.27.22277602","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T14:47:27Z","timestamp":1768488447000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2022.07.27.22277602"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,28]]},"references-count":14,"URL":"https:\/\/doi.org\/10.1101\/2022.07.27.22277602","relation":{"is-preprint-of":[{"id-type":"doi","id":"10.1056\/NEJMc2209479","asserted-by":"subject"}]},"subject":[],"published":{"date-parts":[[2022,7,28]]},"subtype":"preprint"}}