• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Hum Vaccin Immunother . SARS-CoV-2 seroprevalence among healthcare workers in a highly vaccinated Japanese medical center from 2020-2023

tetano

Editor, Senior Moderator
Hum Vaccin Immunother


. 2024 Dec 31;20(1):2337984.
doi: 10.1080/21645515.2024.2337984. Epub 2024 Apr 15. SARS-CoV-2 seroprevalence among healthcare workers in a highly vaccinated Japanese medical center from 2020-2023

Yan Yan[SUP] 1 [/SUP], Kanami Ito[SUP] 2 [/SUP], Hiroshi Fukuda[SUP] 1 2 [/SUP], Shuko Nojiri[SUP] 3 [/SUP], Wataru Urasaki[SUP] 4 5 [/SUP], Takamasa Yamamoto[SUP] 6 [/SUP], Yuki Horiuchi[SUP] 7 [/SUP], Satoshi Hori[SUP] 8 [/SUP], Kazuhisa Takahashi[SUP] 9 [/SUP], Toshio Naito[SUP] 1 2 [/SUP], Yoko Tabe[SUP] 6 7 [/SUP]



Affiliations
Abstract

Infection-induced SARS-CoV-2 seroprevalence has been studied worldwide. At Juntendo University Hospital (JUH) in Tokyo, Japan, we have consistently conducted serological studies using the blood residue of healthcare workers (HCWs) at annual health examinations since 2020. In this 2023 study (n = 3,594), N-specific seroprevalence (infection-induced) was examined while univariate and multivariate logistic regression analyses were performed to compute ORs of seroprevalence with respect to basic characteristics of participants. We found that the N-specific seroprevalence in 2023 was 54.1%-a jump from 17.7% in 2022, and 1.6% in 2021-with 37.9% as non-PCR-confirmed asymptomatic infection cases. Those younger than 50 (adjusted OR = 1.62; p < .001) and recipients with 4 doses or less of vaccine had a higher risk to be N-positive, ranging from 1.45 times higher for the participants with 4 doses (p < .001) to 4.31 times higher for the participants with 1 dose (p < .001), compared to those with 5 or more doses. Our findings indicate that robust vaccination programs may have helped alleviate symptoms but consequently caused asymptomatic spread in this hospital, especially among younger HCWs. Although having four doses or less was found to be associated with higher risk of infection, the optimal constitution and intervals for effective booster vaccines warrant further investigations.

Keywords: COVID-19; Japan; SARS-CoV-2; healthcare worker; mRNA vaccine; seropositive.

 
Back
Top Bottom