臨床研究等提出・公開システム

Date of registration	Jan. 23, 2026
Last modified on	Mar. 18, 2026
Trial ID	jRCT2031250664

Scientific Title	An open-label Phase II study to evaluate the immunogenicity and safety of CH5-HK (HPAIV_H5N1EzoRedFox)
Public Title	HPAIV_H5N1EzoRedFox (HPAIV_H5N1EzoRedFox)

Contact for Scientific Queries	Name	Saito Sho
	Affiliation	Japan Institute for Health Security National Center for Global Health and Medicine
	Address	1-21-1 Toyama, Shinjuku-ku, Tokyo Japan
	Telephone	+81-3-3202-7181
	E-mail	prepandemic-vaccine@jihs.go.jp
Contact for Public Queries	Name	Saito Sho
	Affiliation	Japan Institute for Health Security National Center for Global Health and Medicine
	Address	1-21-1 Toyama, Shinjuku-ku, Tokyo
	Telephone	+81-3-5273-5419
	E-mail	prepandemic-vaccine@jihs.go.jp

Recruitment status	Recruiting

Anticipated date of first enrollment		Jan. 23, 2026
Actual date of first enrollment		Mar. 11, 2026
Target sample size		70
Study Type		Interventional
Study Design	allocation	single arm study
	masking	open(masking not used)
	control	uncontrolled control
	assignment	single assignment
	purpose	prevention purpose
Key inclusion & exclusion criteria	Inclusion Criteria	Healthy adults aged 18 years or older who have not yet been vaccinated against the H5 subtype at the time of informed consent.
	Exclusion Criteria	1) Individuals who have a clear history of H5 subtype influenza (as reported by the subject) 2) Individuals who have previously experienced anaphylaxis due to food, medication or other substances 3) Individuals who have a current history of serious diseases affecting the cardiovascular, hematological, respiratory, hepatic, renal, gastrointestinal, or neuropsychiatric systems. 4) Individuals with a history of Guillain-Barre syndrome or acute disseminated encephalomyelitis 5) Individuals with confirmed influenza infection during the current season (2025/2026) (up to the first vaccination)
	Age Minimum	18age 0month 0week old over
	Age Maximum	No limit
	Gender	Both
Health Condition(s) or Problem(s) Studied		Unvaccinated healthy adults for H5 subtype
Intervention(s)		For healthy adults aged 18 years or older, a dosage is a 0.5 mL suspension for injection containing 3.75 microgram of influenza virus HA fractions (HA content) per dose. This 0.5 mL dose is administered intramuscularly twice, with an interval of at least two weeks between doses.
Primary Outcome(s)		Immunogenicity against A/H5 subtype avian influenza virus (HI antibody titer, etc.)
Secondary Outcome(s)		Side reactions and adverse events. In the event that the HPAIV H5 subtype belonging to Clade 2.3.4.4b becomes a pandemic influenza in the future, serum samples will be stored at the National Institute of Infectious Diseases to estimate the effectiveness of this stockpile vaccine.

Source of Monetary Support	Japan Agency for Medical Research and Development Strategic Center of Biomedical Advanced Vaccine Research and Development for Preparedness and Response
Secondary Sponsor	Not applicable

Name of Certified Review Board	National Hospital Organization Central Review Board
Address	2-5-21, Higashigaoka, Meguro-ku, Tokyo, Tokyo
Telephone	+81-3-5712-5050
E-Mail	700-crb@mail.hosp.go.jp
Approval Status	Approval
Date of approval	Dec. 09, 2025

Plan to share IPD	No

Countries of Recruitment（Except Japan）	none

History of Changes

No	Publication date
2	Mar. 18, 2026	(this page)	Changes
1	Jan. 23, 2026	Detail

List of change history