{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T05:20:43Z","timestamp":1786598443848,"version":"build-2736575974"},"reference-count":17,"publisher":"Oxford University Press (OUP)","issue":"Supplement_2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2022,10,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Households have emerged as important venues for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Little is known, however, regarding the magnitude and determinants of household transmission in increasingly vaccinated populations.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>From September 2020 to January 2022, symptomatic nonhospitalized individuals with SARS-CoV-2 infection by RNA detection were identified within 5 days of symptom onset; all individuals resided with at least 1 other SARS-CoV-2\u2013uninfected household member. These infected persons (cases) and their household members (contacts) were subsequently followed with questionnaire-based measurement and serial nasal specimen collection. The primary outcome was SARS-CoV-2 infection among contacts.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>We evaluated 42 cases and their 74 household contacts. Among the contacts, 32 (43%) became infected, of whom 5 (16%) were asymptomatic; 81% of transmissions occurred by 5 days after the case\u2019s symptom onset. From 21 unvaccinated cases, 14-day cumulative incidence of SARS-CoV-2 infection among contacts was 18\/40 (45% [95% confidence interval {CI}, 29%\u201362%]), most of whom were unvaccinated. From 21 vaccinated cases, 14-day cumulative incidence of SARS-CoV-2 infection was 14\/34 (41% [95% CI, 25%\u201359%]) among all contacts and 12\/29 (41% [95% CI, 24%\u201361%]) among vaccinated contacts. At least 1 comorbid condition among cases and 10 or more days of RNA detection in cases were associated with increased risk of infection among contacts.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Among households including individuals with symptomatic SARS-CoV-2 infection, both vaccinated-to-vaccinated and unvaccinated-to-unvaccinated transmission of SARS-CoV-2 to household contacts was common. Because vaccination alone did not notably reduce risk of infection, household contacts will need to employ additional interventions to avoid infection.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/cid\/ciac545","type":"journal-article","created":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T13:07:02Z","timestamp":1657026422000},"page":"S193-S204","source":"Crossref","is-referenced-by-count":17,"title":["Magnitude and Determinants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Household Transmission: A Longitudinal Cohort Study"],"prefix":"10.1093","volume":"75","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7616-0321","authenticated-orcid":false,"given":"J Daniel","family":"Kelly","sequence":"first","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"},{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"},{"name":"F.I. Proctor Foundation, University of California, San Francisco , San Francisco, California , USA"},{"name":"San Francisco Veterans Affairs Medical Center , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Scott","family":"Lu","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"},{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Khamal","family":"Anglin","sequence":"additional","affiliation":[{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miguel","family":"Garcia-Knight","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jesus","family":"Pineda-Ramirez","sequence":"additional","affiliation":[{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah A","family":"Goldberg","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"Tassetto","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amethyst","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin","family":"Donohue","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle C","family":"Davidson","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariela","family":"Romero","sequence":"additional","affiliation":[{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruth","family":"Diaz Sanchez","sequence":"additional","affiliation":[{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manuella","family":"Djomaleu","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sujata","family":"Mathur","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica Y","family":"Chen","sequence":"additional","affiliation":[{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carrie A","family":"Forman","sequence":"additional","affiliation":[{"name":"School of Medicine, Drexel University , Philadelphia, Pennsylvania , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Venice","family":"Servellita","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rubi D","family":"Montejano","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua R","family":"Shak","sequence":"additional","affiliation":[{"name":"San Francisco Veterans Affairs Medical Center , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"George W","family":"Rutherford","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"},{"name":"Institute for Global Health Sciences, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven G","family":"Deeks","sequence":"additional","affiliation":[{"name":"Division of HIV, Infectious Diseases and Global Medicine, Zuckerberg San Francisco General Hospital , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Glen R","family":"Abedi","sequence":"additional","affiliation":[{"name":"Respiratory Viruses Branch, Division of Viral Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melissa A","family":"Rolfes","sequence":"additional","affiliation":[{"name":"Respiratory Viruses Branch, Division of Viral Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sharon","family":"Saydah","sequence":"additional","affiliation":[{"name":"Respiratory Viruses Branch, Division of Viral Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melissa","family":"Briggs-Hagen","sequence":"additional","affiliation":[{"name":"Respiratory Viruses Branch, Division of Viral Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael J","family":"Peluso","sequence":"additional","affiliation":[{"name":"Division of HIV, Infectious Diseases and Global Medicine, Zuckerberg San Francisco General Hospital , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charles","family":"Chiu","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claire M","family":"Midgley","sequence":"additional","affiliation":[{"name":"Respiratory Viruses Branch, Division of Viral Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raul","family":"Andino","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffrey N","family":"Martin","sequence":"additional","affiliation":[{"name":"Department of Epidemiology and Biostatistics, University of California, San Francisco , San Francisco, California , USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2022,7,5]]},"reference":[{"key":"2022101111362834000_ciac545-B1","doi-asserted-by":"crossref","first-page":"e229317","DOI":"10.1001\/jamanetworkopen.2022.9317","article-title":"Household secondary attack rates of SARS-CoV-2 by variant and vaccination status: an updated systematic review and meta-analysis","volume":"5","author":"Madewell","year":"2022","journal-title":"JAMA Netw Open"},{"key":"2022101111362834000_ciac545-B2","doi-asserted-by":"crossref","first-page":"1987","DOI":"10.1093\/infdis\/jiab528","article-title":"Low sensitivity of rapid antigen tests to detect severe acute respiratory syndrome coronavirus 2 infections before and on the day of symptom onset in nursing home staff and residents, Germany, January\u2013March 2021","volume":"224","author":"Bender","year":"2021","journal-title":"J Infect Dis"},{"key":"2022101111362834000_ciac545-B3","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciab973","article-title":"BNT162b2 mRNA vaccine effectiveness given confirmed exposure: analysis of household members of COVID-19 patients [manuscript published online ahead of print 24 November 2021]","author":"Gazit","year":"2021","journal-title":"Clin Infect Dis"},{"key":"2022101111362834000_ciac545-B4","first-page":"2100640","article-title":"Vaccine effectiveness against SARS-CoV-2 transmission and infections among household and other close contacts of confirmed cases, the Netherlands, February to May 2021","volume":"26","author":"de Gier","year":"2021","journal-title":"Euro Surveill"},{"key":"2022101111362834000_ciac545-B5","doi-asserted-by":"crossref","first-page":"100299","DOI":"10.1016\/j.lanwpc.2021.100299","article-title":"Impact of Delta variant and vaccination on SARS-CoV-2 secondary attack rate among household close contacts","volume":"17","author":"Ng","year":"2021","journal-title":"Lancet Reg Health West Pac"},{"key":"2022101111362834000_ciac545-B6","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/S1473-3099(21)00648-4","article-title":"Community transmission and viral load kinetics of the SARS-CoV-2 Delta (B.1.617.2) variant in vaccinated and unvaccinated individuals in the UK: a prospective, longitudinal, cohort study","volume":"22","author":"Singanayagam","year":"2022","journal-title":"Lancet Infect Dis"},{"key":"2022101111362834000_ciac545-B7","first-page":"2100977","article-title":"Vaccine effectiveness against SARS-CoV-2 transmission to household contacts during dominance of Delta variant (B.1.617.2), the Netherlands, August to September 2021","volume":"26","author":"de Gier","year":"2021","journal-title":"Euro Surveill"},{"key":"2022101111362834000_ciac545-B8","author":"Centers for Disease Control and Prevention, National Notifiable Diseases Surveillance System","year":"2021"},{"key":"2022101111362834000_ciac545-B9","author":"Centers for Disease Control and Prevention","year":"2022"},{"key":"2022101111362834000_ciac545-B10","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1097\/00006842-200203000-00008","article-title":"The PHQ-15: validity of a new measure for evaluating the severity of somatic symptoms","volume":"64","author":"Kroeke","year":"2022","journal-title":"Psychosom Med"},{"key":"2022101111362834000_ciac545-B11","doi-asserted-by":"publisher","DOI":"10.1101\/2202.05.15.22275051","article-title":"Infectious viral shedding of SARS-CoV-2 Delta following vaccination: a longitudinal cohort study","author":"Garcia-Knight","year":"2022","journal-title":"medRxiv [Preprint]. Posted online"},{"key":"2022101111362834000_ciac545-B12","doi-asserted-by":"publisher","DOI":"10.1101\/2020.09.04.28307","article-title":"Improvements to the ARTIC multiplex PCR method for SARS-CoV-2 genome sequencing using nanopore","author":"Tyson","year":"2020","journal-title":"bioRxiv [Preprint]. Posted online 4 September"},{"key":"2022101111362834000_ciac545-B13","author":"Miller"},{"key":"2022101111362834000_ciac545-B14","first-page":"2906","article-title":"Augur: a bioinformatics toolkit for phylogenetic analyses of human pathogens","volume-title":"J Open Source Softw","author":"Huddleston","year":"2021"},{"key":"2022101111362834000_ciac545-B15","doi-asserted-by":"crossref","first-page":"177","DOI":"10.15585\/mmwr.mm7105e1","article-title":"SARS-CoV-2 infection and hospitalization among adults aged \u226518 years, by vaccination status, before and during SARS-CoV-2 B.1.1.529 (Omicron) variant predominance\u2014Los Angeles County, California, 7 November, 2021\u20138 January, 2022","volume":"71","author":"Danza","year":"2022","journal-title":"MMWR Morb Mortal Wkly Rep"},{"key":"2022101111362834000_ciac545-B16","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1001\/jama.2021.24868","article-title":"Characteristics and outcomes of hospitalized patients in South Africa during the COVID-19 Omicron wave compared with previous waves","volume":"327","author":"Maslo","year":"2021","journal-title":"JAMA"},{"key":"2022101111362834000_ciac545-B17","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1016\/S1473-3099(20)30985-3","article-title":"Transmission of COVID-19 in 282 clusters in Catalonia, Spain: a cohort study","volume":"21","author":"Marks","year":"2021","journal-title":"Lancet Infect Dis"}],"container-title":["Clinical Infectious Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/cid\/advance-article-pdf\/doi\/10.1093\/cid\/ciac545\/44408807\/ciac545.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/cid\/article-pdf\/75\/Supplement_2\/S193\/46434816\/ciac545.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/cid\/article-pdf\/75\/Supplement_2\/S193\/46434816\/ciac545.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,10,11]],"date-time":"2022-10-11T11:36:56Z","timestamp":1665488216000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/cid\/article\/75\/Supplement_2\/S193\/6631204"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,7,5]]},"references-count":17,"journal-issue":{"issue":"Supplement_2","published-online":{"date-parts":[[2022,7,5]]},"published-print":{"date-parts":[[2022,10,3]]}},"URL":"https:\/\/doi.org\/10.1093\/cid\/ciac545","relation":{},"ISSN":["1058-4838","1537-6591"],"issn-type":[{"value":"1058-4838","type":"print"},{"value":"1537-6591","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2022,10,1]]},"published":{"date-parts":[[2022,7,5]]}}}