Healthy vaccinee effect: a bias not to be forgotten in observational studies on COVID‑19 vaccine effectiveness
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F24%3A73627553" target="_blank" >RIV/61989592:15310/24:73627553 - isvavai.cz</a>
Result on the web
<a href="https://pamw.pl/en/node/16634/pdf" target="_blank" >https://pamw.pl/en/node/16634/pdf</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.20452/pamw.16634" target="_blank" >10.20452/pamw.16634</a>
Alternative languages
Result language
angličtina
Original language name
Healthy vaccinee effect: a bias not to be forgotten in observational studies on COVID‑19 vaccine effectiveness
Original language description
Objectives:We investigated the validity of claims of the healthy vaccinee effect (HVE) in COVID-vaccine studies by analyzing associations between all-cause mortality (ACM) and COVID-19 vaccination status.Methods:Approximately 2.2 million individual records from two Czech health insurance companies were retrospectively analyzed. Each age group was stratified according to the vaccination status (unvaccinated vs. individuals less than 4 weeks vs. more than 4 weeks from Doses 1, 2, 3, and 4 or more doses of vaccine). ACMs in these groups were computed and compared.Results: Consistently over datasets and age categories, ACM was substantially lower in the vaccinated than unvaccinated groups regardless of the presence or absence of a wave of COVID-19 deaths. Moreover, the ACMs in groups more than 4 weeks from Doses 1, 2, or 3 were consistently several times higher than in those less than 4 weeks from the respective dose. HVE appears to be the only plausible explanation for this, which is further corroborated by a created mathematical model. Conclusions: In view of the presence of HVE, the baseline difference in the frailty of vaccinated and unvaccinated populations in periods without COVID-19 must be taken into account when estimating COVID-19 vaccine effectiveness from observational data.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10103 - Statistics and probability
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2024
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Polish Archives of Internal Medicine-Polskie Archiwum Medycyny Wewnetrznej
ISSN
0032-3772
e-ISSN
1897-9483
Volume of the periodical
134
Issue of the periodical within the volume
2
Country of publishing house
PL - POLAND
Number of pages
2
Pages from-to
"16634-1"-"16634-2"
UT code for WoS article
001182539800009
EID of the result in the Scopus database
2-s2.0-85186742855