An Experimental Medicine Decipher of a Minimum Correlate of Cellular Immunity

Launched by SINGAPORE GENERAL HOSPITAL · Oct 3, 2022

Keywords

ClinConnect Summary

This clinical trial is investigating how different vaccines for yellow fever and Japanese encephalitis can affect the body's immune response when exposed to these viruses. Specifically, the researchers want to see if having a higher number of certain immune cells (called CD4+ and CD8+ T cells) can help reduce the amount of virus in the body after vaccination and subsequently when challenged with a related virus. The trial involves 58 healthy adults, aged 21 to 45, who will be randomly assigned to receive different vaccine combinations. Participants will receive one vaccine on the first day and another vaccine 28 days later.

To be eligible for this study, participants must be in good health, have no major medical conditions, and be able to give informed consent. Women who can become pregnant need to have a negative pregnancy test and agree to use reliable birth control during the study. Throughout the trial, participants will be monitored closely for their health and reactions to the vaccines. This study is important for understanding how vaccination can enhance our immune defenses against infectious diseases.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 1. Healthy adults, 21-45 years of age at time of screening
• • 2. Willing to comply to study procedures and adhere to study schedule visits.
• • 3. Satisfactory baseline medical assessment as assessed by physical examination and a stable health status. The laboratory values must be within the normal range of the assessing site or show abnormalities that are deemed not clinically significant as judged by the investigator. A stable health status is defined as the absence of a health event satisfying the definition of a serious adverse event.
• • 4. Accessible vein for blood collection.
• • 5. Ability to provide informed consent.
• • 6. Female subjects of non-child bearing potential due to surgical sterilization (hysterectomy or bilateral oophorectomy or tubal ligation) or menopause. Post-menopausal subjects must have had at least 12 months of natural (spontaneous) amenorrhea
• • 7. Female subjects of child bearing potential with negative urine pregnancy tests on the day of screening and vaccination.
• • 8. Both male (if he has a partner of childbearing potential) and female subjects (of childbearing potential) must agree to use adequate and reliable contraceptive measures (e.g. spermicides, condoms, contraceptive pills) or practice abstinence for 10 days after vaccination.
• Exclusion Criteria:
• • 1. History of presence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, neuropsychiatric, haematological, endocrine or immunosuppressive disorders that would be a risk factor when administered the investigational product (IP)
• • 2. Previous receipt of Imojev, Stamaril or Ixiaro vaccines, or any other yellow fever or Japanese encephalitis vaccines
• • 3. Previous history of Yellow fever virus or Japanese encephalitis infection
• • 4. Known allergy to Imojev, Stamaril or Ixiaro vaccines or their components
• • 5. History of severe food/drug/vaccine allergies e.g. angioedema, anaphylaxis
• • 6. Known allergy to egg or egg products
• • 7. History of thymus gland disease
• • 8. Diagnosed with cancer or on treatment for cancer (with the exception of localized basal cell carcinoma) within 3 years prior to screening
• • 9. Evidence of clinically significant anemia (Hb \<10 g/dl)
• • 10. Blood donation exceeding \>450mls in the past 3 months
• • 11. Presence of acute infection in the preceding 7 days or presence of a temperature ≥ 38.0°C (oral or tympanic temperature assessment), or acute symptoms greater than of "mild" severity on the scheduled date of first dose
• • 12. Woman who is pregnant or breast feeding
• • 13. Evidence of substance abuse, or previous substance abuse including alcohol
• • 14. Participation in a study involving administration of an investigational compound (including investigational vaccines) within the past three months, or planned participation during the duration of this study.
• • 15. Receipt of anti-inflammatory drugs (such as NSAIDs or systemic steroids) in the past 7 days.
• • 16. Receipt of any licensed vaccine in the past 30 days before the first study vaccine dose.
• • 17. Positive serum Dengue IgG by ELISA
• • 18. Any condition that, in the opinion of the investigator, would complicate or compromise the study or wellbeing of the subject.