In short
INFLUENZA B VIRUS, STRAIN B/TOKYO/EIS13-175/2025 (WILD TYPE), INACTIVATED is an inactivated influenza B virus strain used in flu vaccines. It is being studied in two authorised clinical trials: a Phase 2 trial in 100 people with early type 1 diabetes, and a Phase 3 trial in 180 adults treated for hematological cancer. Both trials use the vaccine as an intramuscular injection.
Key points
- Phase 2 trial in 100 people with early type 1 diabetes
- Phase 3 trial in 180 adults with hematological cancer
- Both trials are authorised but not yet recruiting
- Given as an intramuscular injection of 0.5 ml
- Studied to see if flu vaccination can preserve beta cell function in diabetes
- Also studied to compare high-dose versus standard-dose flu vaccine in cancer patients
What is influenza B virus vaccine?
INFLUENZA B VIRUS, STRAIN B/TOKYO/EIS13-175/2025 (WILD TYPE), INACTIVATED is an inactivated influenza B virus strain. It is a component of flu vaccines, where the virus has been killed so it cannot cause infection but can still trigger an immune response. In the clinical trial records, this substance appears as part of trivalent and quadrivalent influenza vaccines, which contain inactivated split virion influenza virus.
The substance is classified in the EU Clinical Trials Information System under hormonal diseases, hemic and lymphatic diseases, and immune system diseases as therapeutic areas.
How does it work?
Influenza vaccines containing this inactivated B virus strain work by exposing the immune system to killed virus particles. This stimulates the body to produce antibodies against the influenza B virus without causing the flu itself. In the diabetes trial, researchers are investigating whether this immune stimulation can also help preserve the function of insulin-producing beta cells in the pancreas.
In the hematological cancer trial, the focus is on seroconversion — the development of antibodies against at least one of the four vaccine antigens measured 28 days after vaccination.
Which conditions is it studied for?
- Type 1 diabetes — an autoimmune condition where the body's immune system destroys insulin-producing beta cells in the pancreas. The trial investigates whether influenza vaccination can preserve remaining beta cell function in people with early type 1 diabetes.
- Hematological cancer — cancers affecting the blood, bone marrow or lymph nodes. The trial includes patients with myeloma, other B-cell malignancies and myeloid malignancies who are being treated for their cancer.
How is it given?
The vaccines containing this inactivated influenza B virus strain are given as an intramuscular injection. In the diabetes trial, the vaccine is administered as a 0.5 ml injection into the muscle. In the hematological cancer trial, both the high-dose and standard-dose vaccines are given as 0.5 ml intramuscular injections in pre-filled syringes.
What do the clinical trials show?
Two authorised clinical trials include this inactivated influenza B virus strain. The first is a Phase 2 trial called the INVITED trial, which plans to enrol 100 participants with early type 1 diabetes. Its main outcome measure is the change in fasting residual beta cell function, measured by C-peptide levels, from baseline to 12 months.
The second is a Phase 3 single-blind randomised trial comparing high-dose versus standard-dose inactivated influenza vaccine in 180 adults treated for hematological cancer. The primary endpoints are seroconversion to at least one of the four vaccine antigens at 28 days after vaccination, and the identification of a baseline immune signature that predicts response to the vaccine.
Both trials are currently authorised, meaning they have received regulatory approval to proceed but are not yet recruiting participants.
Who can take part in these trials?
The INVITED trial is for people with early type 1 diabetes mellitus. The hematological cancer trial is for adult patients treated for hematological cancer, with planned recruitment of approximately 80 myeloma patients, 40 other B-cell malignancy patients, and 20 patients treated for a myeloid malignancy. The study also includes 40 healthy control subjects for the systems biology part of the research.