tetano
Editor, Senior Moderator
- Martin Šmíd[SUP]1,2,3,*[/SUP] , Tamara Barusová[SUP]4,*[/SUP] , Jiří Jarkovský[SUP]5,6,*[/SUP] , Ondřej Májek[SUP]5,6,*[/SUP] , Tomáš Pavlík[SUP]5,6,*[/SUP] , Lenka Přibylová[SUP]7,*[/SUP] , Josefína Weinerová[SUP]8,*[/SUP] , Milan Zajíček[SUP]1,2,*[/SUP] , Jan Trnka[SUP]1,9,*[/SUP]
COVID-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.
Aim
We 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.
Methods
We 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.
Results
Recently 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.
Conclusion
Vaccination 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.
https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2024.29.35.2300690#html_fulltext