Protection by Vaccines and Previous Infection Against the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2
Language English Country United States Media print
Document type Journal Article
PubMed
35482442
PubMed Central
PMC9129207
DOI
10.1093/infdis/jiac161
PII: 6575414
Knihovny.cz E-resources
- Keywords
- COVID-19, Omicron variant, SARS-CoV-2, hospitalization, postinfection immunity, vaccine effectiveness,
- MeSH
- COVID-19 * prevention & control MeSH
- Humans MeSH
- SARS-CoV-2 MeSH
- Vaccination MeSH
- Vaccines * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Vaccines * MeSH
BACKGROUND: The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evades immunity conferred by vaccines and previous infections. METHODS: We used a Cox proportional hazards model and a logistic regression on individual-level population-wide data from the Czech Republic to estimate risks of infection and hospitalization, including severe states. RESULTS: A recent (≤2 months) full vaccination reached vaccine effectiveness (VE) of 43% (95% confidence interval [CI], 42%-44%) against infection by Omicron compared to 73% (95% CI, 72%-74%) against Delta. A recent booster increased VE to 56% (95% CI, 55%-56%) against Omicron infection compared to 90% (95% CI, 90%-91%) for Delta. The VE against Omicron hospitalization of a recent full vaccination was 45% (95% 95% CI, 29%-57%), with a recent booster 87% (95% CI, 84%-88%). The VE against the need for oxygen therapy due to Omicron was 57% (95% CI, 32%-72%) for recent vaccination, 90% (95% CI, 87%-92%) for a recent booster. Postinfection protection against Omicron hospitalization declined from 68% (95% CI, 68%-69%) at ≤6 months to 13% (95% CI, 11%-14%) at >6 months after a previous infection. The odds ratios for Omicron relative to Delta were 0.36 (95% CI, .34-.38) for hospitalization, 0.24 (95% CI, .22-.26) for oxygen, and 0.24 (95% CI, .21-.28) for intensive care unit admission. CONCLUSIONS: Recent vaccination still brings substantial protection against severe outcome for Omicron.
1st Faculty of Medicine Charles University Prague Czech Republic
Centre for Modelling of Biological and Social Processes Prague Czech Republic
Department of Mathematics and Statistics Faculty of Science Masaryk University Brno Czech Republic
Institute of Biostatistics and Analyses Faculty of Medicine Masaryk University Brno Czech Republic
Institute of Information Theory and Automation Czech Academy of Sciences Prague Czech Republic
References provided by Crossref.org
COVID-19: years of life lost (YLL) and saved (YLS) as an expression of the role of vaccination
