臨床研究等提出・公開システム

Effectiveness of Adapted COVID-19 Vaccine (BNT162b2) among Older Adults in Emergency Departments in Japan: A Test-Negative Design

Effectiveness of Adapted COVID-19 Vaccine (BNT162b2) among Older Adults in Emergency Departments in Japan: A Test-Negative Design

Goto Tadahiro

TXP Medical Co. Ltd.

706 H1O Kanda 41-1 Higashimatsushita-cho, Chiyoda-ku, Tokyo 101-0042

tadahiro.goto@txpmedical.com

Yano Ayako

TXP Medical Co. Ltd.

706 H1O Kanda 41-1 Higashimatsushita-cho, Chiyoda-ku, Tokyo 101-0042

+81-3-5615-8433

ayako.yano@txpmedical.com

Suspended

June. 23, 2025

Observational

This study comprises two phases (2024/2025 season and 2025/2026 season).
1. Individuals aged 65 years or older.
2. For 2024/2025 season, we include patients who visited or will visit the emergency department (ED) of study sites and hospitalized during the study period and underwent SARS-CoV-2 testing (either rapid antigen or RT-PCR) for symptoms consistent with COVID-19.
3. For 2025/2026 season, we include patients who visited or will visit the ED of study sites during the study period and underwent SARS-CoV-2 testing (either rapid antigen or RT-PCR) for symptoms consistent with COVID-19.
4. Patients for whom SARS-CoV-2 testing is deemed necessary by a physician. Symptoms suggestive of COVID-19 include fever, altered consciousness, sore throat, headache, diarrhea, cough, or shortness of breath.

1. Prior SARS-CoV-2 test results outside of participating hospitals within 90 days
2. Had invalid SARS-CoV-2 test results
3. Received an adapted COVID-19 vaccine BNT162b2 within 2 months after a prior COVID-19 vaccination.
4. Received an adapted COVID-19 vaccine BNT162b2 within 14 days prior to the SARS-CoV-2 test.
5. Received nirmatrelvir/ritonavir or any other COVID-19 outpatient antiviral in the 30 days or monoclonal antibody in the 180 days prior to the SARS-CoV-19 test.
6. Had a hospitalization that, despite having an ARI diagnosis with a positive SARS-CoV-2 test, was determined to be likely unrelated to COVID-19 or clearly related to another cause.

For multiple visits or admissions of the same patient, visits within 29 days of the previous event are considered part of the same episode and are not counted. Visits after 30 days or more are treated as separate episodes (separate cases).

Patients who underwent SARS-CoV-2 testing for symptoms consistent with COVID-19 and hospitalized

COVID-19-associated hospitalization

Severe COVID-19 defined as the need for supplementary oxygenation or respiratory support (use of nasal high-flow oxygen therapy, noninvasive positive pressure ventilation [NPPV], or mechanical ventilation), ICU admission, all-cause in-hospital death, and VE durability against hospitalization.

+81-3-3263-4801

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