A Booster Study of S-268023 (COVID-19)

A Phase 3, Randomized, Observer-Blind, Active-Controlled Study to Investigate the Immunogenicity of a Booster Dose of S-268023 compared with COMIRNATY (COVID-19)

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2031230503

Enrollment

600

Registered

2023-12-11

Start date

2023-12-16

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

Prevention of COVID-19

Interventions

Intramuscular injection of S-268023 or COMIRNATY RTU intramuscular injection (XBB.1.5 variant)

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: -Participants aged 20 years or older, at the time of sigining the informed consent form. -Participants who have passed 90 days or more after completing the primary vaccination or booster vaccination with an approved SARS-CoV-2 vaccine (excluding an approved monovalent XBB.1.5 SARS-CoV-2 vaccine). -Participants with no infection history of SARS-CoV-2, or participants with infection history of SARS-CoV-2 who have not been infected since March 2023. -Male and female.

Exclusion criteria

Exclusion criteria: -Participants who have previously received an approved monovalent XBB.1.5 SARS-CoV-2 vaccines. -Participants who tested positive SARS-CoV-2 infection (as determined by SARS-CoV-2 antigen test) at Screening.

Design outcomes

Primary

Measure	Time frame
SARS-CoV-2 neutralizing antibody titer on day 29 (XBB.1.5 variant) -GMT -Seroresponse rate	—

Contacts

Public ContactCorporate Communications Department

Shionogi & Co., Ltd.

shionogiclintrials-admin@shionogi.co.jp+81-6-6209-7885

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026