| Autor: |
Šmíd M; Centre for Modelling of Biological and Social Processes, Prague, Czechia.; All authors contributed equally to this work.; Department of Econometrics, Institute of Information Theory and Automation, Czech Academy of Sciences, Prague, Czechia.; Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Prague, Czechia., Barusová T; All authors contributed equally to this work.; Institute of Biostatistics and Analyses, Ltd., Brno, Czechia., Jarkovský J; All authors contributed equally to this work.; Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czechia.; Institute of Health Information and Statistics of the Czech Republic, Prague, Czechia., Májek O; All authors contributed equally to this work.; Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czechia.; Institute of Health Information and Statistics of the Czech Republic, Prague, Czechia., Pavlík T; All authors contributed equally to this work.; Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czechia.; Institute of Health Information and Statistics of the Czech Republic, Prague, Czechia., Přibylová L; All authors contributed equally to this work.; Department of Mathematics and Statistics, Faculty of Science, Masaryk University, Brno, Czechia., Weinerová J; All authors contributed equally to this work.; School of Psychology, University of Nottingham, University Park, Nottingham, United Kingdom., Zajíček M; Centre for Modelling of Biological and Social Processes, Prague, Czechia.; All authors contributed equally to this work.; Department of Econometrics, Institute of Information Theory and Automation, Czech Academy of Sciences, Prague, Czechia., Trnka J; Centre for Modelling of Biological and Social Processes, Prague, Czechia.; All authors contributed equally to this work.; Department of Biochemistry, Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czechia. |
| Abstrakt: |
BackgroundCOVID-19 remains a major infectious disease with substantial implications for individual and public health including the risk of a post-infection syndrome, long COVID. The continuous changes in dominant variants of SARS-CoV-2 necessitate a careful study of the effect of preventative strategies.AimWe aimed to estimate the effectiveness of post-vaccination, post-infection and hybrid immunity against severe cases requiring oxygen support caused by infections with SARS-CoV-2 variants BA1/2 and BA4/5+, and against long COVID in the infected population and their changes over time.MethodsWe used a Cox regression analysis with time-varying covariates and calendar time and logistic regression applied to national-level data from Czechia from December 2021 until August 2023.ResultsRecently boosted vaccination, post-infection and hybrid immunity provide significant protection against a severe course of COVID-19, while unboosted vaccination more than 10 months ago has a negligible protective effect. The post-vaccination immunity against the BA1/2 or BA4/5+ variants, especially based on the original vaccine types, appears to wane rapidly compared with post-infection and hybrid immunity. Once infected, however, previous immunity plays only a small protective role against long COVID.ConclusionVaccination remains an effective preventative measure against a severe course of COVID-19 but its effectiveness wanes over time thus highlighting the importance of booster doses. Once infected, vaccines may have a small protective effect against the development of long COVID. |
