Investigation of SARS-CoV-2 seroprevalence in relation to natural infection and vaccination between October 2020 and September 2021 in the Czech Republic: a prospective national cohort study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F23%3A00130673" target="_blank" >RIV/00216224:14310/23:00130673 - isvavai.cz</a>

Result on the web

<a href="https://bmjopen.bmj.com/content/13/3/e068258.long" target="_blank" >https://bmjopen.bmj.com/content/13/3/e068258.long</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1136/bmjopen-2022-068258" target="_blank" >10.1136/bmjopen-2022-068258</a>

Result language

angličtina

Original language name

Investigation of SARS-CoV-2 seroprevalence in relation to natural infection and vaccination between October 2020 and September 2021 in the Czech Republic: a prospective national cohort study

Original language description

Objective Examine changes in SARS-CoV-2 seropositivity before and during the national vaccination campaign in the Czech Republic. Design Prospective national population-based cohort study. Setting Masaryk University, RECETOX, Brno. Participants 22 130 persons provided blood samples at two time points approximately 5–7 months apart, between October 2020 and March 2021 (phase I, before vaccination), and between April and September 2021 (during vaccination campaign). Outcome measures Antigen-specific humoral immune response was analysed by detection of IgG antibodies against the SARS-CoV-2 spike protein by commercial chemiluminescent immunoassays. Participants completed a questionnaire that included personal information, anthropometric data, self-reported results of previous RTPCR tests (if performed), history of symptoms compatible with COVID-19 and records of COVID-19 vaccination. Seroprevalence was compared between calendar periods, previous RT-PCR results, vaccination and other individual characteristics. Results Before vaccination (phase I), seroprevalence increased from 15% in October 2020 to 56% in March 2021. By the end of phase II, in September 2021, prevalence increased to 91%; the highest seroprevalence was seen among vaccinated persons with and without previous SARS-CoV-2 infection (99.7% and 97.2%, respectively), while the lowest seroprevalence was found among unvaccinated persons with no signs of disease (26%). Vaccination rates were lower in persons who were seropositive in phase I but increased with age and body mass index. Only 9% of unvaccinated subjects who were seropositive in phase I became seronegative by phase II. Conclusions The rapid increase in seropositivity during the second wave of the COVID-19 epidemic (covered by phase I of this study) was followed by a similarly steep rise in seroprevalence during the national vaccination campaign, reaching seropositivity rates of over 97% among vaccinated persons.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

30218 - General and internal medicine

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

BMJ Open

ISSN

2044-6055

e-ISSN

2044-6055

Volume of the periodical

13

Issue of the periodical within the volume

3

Country of publishing house

GB - UNITED KINGDOM

Number of pages

7

Pages from-to

1-7

UT code for WoS article

001003285100110

EID of the result in the Scopus database

2-s2.0-85150008508