Immune response after two doses of COVID-19 vaccination

Epidemiological study on changes in immune response after two doses of COVID-19 vaccination

Status

Active, not recruiting

Phases

Phase 4

Study type

Observational

Source

JPRN

Registry ID

JPRN-jRCT1051210161

Enrollment

600

Registered

2022-01-23

Start date

2022-01-24

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Coronavirus Disease 2019

Interventions

None listed

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Those who meet all of the following 1) to 6) 1) Persons who meet any of the following (a), (b) and (c) (a) Participants of "Prospective cohort study of effectiveness and safety of COVID-19 vaccines in Osaka, Japan" * (b) Staff of Osaka City (Metropolitan) University Hospital (c) Faculty / Students of Osaka City (Metropolitan) University School of Medicine / Graduate School of Medicine * Approval number by Osaka City (Metropolitan) University Hospital Certified Review Board: OCU010E, jRCT registration number: jRCT105120014 2) Aged 20 years or older 3) Those who have received two doses of COVID-19 vaccines 4) Those who have passed 5 months since the second dose of COVID-19 vaccines 5) Those who are expected to be able to provide their blood in a predefined number of times during the study period 6) Persons who have voluntarily provided written informed consent for participation

Exclusion criteria

Exclusion criteria: Persons who meet any of the following 1) 2) 1) Those who have received pre-licensure COVID-19 vaccines in the past (e.g., participation in clinical trials before licensure) 2) Those who are judged to be ineligible for research by the principal investigator or the investigator

Design outcomes

Primary

Measure	Time frame
Humoral immune response: changes in antibody titer against SARS-CoV2-Spike protein	—

Secondary

Measure	Time frame
(1) Humoral immune response: changes in neutralizing antibody titer against SARS-CoV2 (2) Vaccine effectiveness against laboratory-confirmed COVID-19 (including PCR positive, antigen-testing positive, and serological infection) (3) Vaccine effectiveness against COVID-19-like diseases (4) Occurrence of adverse reactions after vaccination (5) Occurrence of diseases suspected to be caused by vaccination [Exploratory outcome(s)] (1) Cell-mediated immunity: SARS-CoV-2 S antigen-specific T cell and B cell function (2) Antibody subclasses	—

Measure

Time frame

(1) Humoral immune response: changes in neutralizing antibody titer against SARS-CoV2 (2) Vaccine effectiveness against laboratory-confirmed COVID-19 (including PCR positive, antigen-testing positive, and serological infection) (3) Vaccine effectiveness against COVID-19-like diseases (4) Occurrence of adverse reactions after vaccination (5) Occurrence of diseases suspected to be caused by vaccination [Exploratory outcome(s)] (1) Cell-mediated immunity: SARS-CoV-2 S antigen-specific T cell and B cell function (2) Antibody subclasses

—

Contacts

Public ContactWakaba Fukushima

Osaka Metropolitan University

wakaba@omu.ac.jp+81-6-6645-3756

Outcome results