Yellow Fever Vaccine 17D Immunogenicity for Yellow Fever

Overseen By Sarah Siegel, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: Oregon Health and Science University

Must not be taking: Oral steroids, Immunoglobulins

Disqualifiers: Neurologic disorder, Immunodeficiency, Obesity, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

35 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how individuals previously vaccinated with the yellow fever vaccine respond to a second dose of the 17D vaccine. Researchers aim to observe changes in antibody and immune cell responses following revaccination. The trial seeks healthy adults who received the yellow fever vaccine at least eight years ago. Participants will receive a second vaccination and undergo multiple blood tests to monitor immune responses. As a Phase 1 trial, this research focuses on understanding the treatment's effects in people, providing participants an opportunity to contribute to groundbreaking insights on vaccine responses.

Do I need to stop taking my current medications to join the trial?

The trial does not specify if you need to stop taking your current medications, but you cannot have used oral steroids, immunoglobulins, or certain other medications recently. It's best to discuss your specific medications with the trial team.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research shows that the yellow fever vaccine 17D is generally safe, with most people experiencing only mild reactions. Common side effects include headaches, muscle pain, and mild fever. However, rare cases of more serious issues, such as severe allergic reactions or nervous system problems, have occurred, though these are uncommon.

The vaccine has been used for a long time and is considered one of the safest available. Most issues have been reported after initial vaccination. Since this trial involves individuals who have already been vaccinated, the risk of severe reactions might be lower. Overall, the yellow fever vaccine 17D is well-tolerated by most people. ^{1 2 3 4 5}

Why are researchers excited about this study treatment for yellow fever?

Researchers are excited about the yellow fever vaccine 17D because it has a long history of being highly effective. Unlike many treatments that may take time to work, this vaccine quickly stimulates the immune system to provide protection against yellow fever. It's administered as a single subcutaneous injection, which is convenient and straightforward. Additionally, the 17D vaccine has a proven track record of safety and efficacy, which makes it a cornerstone in preventing yellow fever outbreaks.

What evidence suggests that the yellow fever vaccine 17D is effective for yellow fever?

Research shows that the yellow fever 17D vaccine works effectively. Studies indicate it helps the body build strong protection against yellow fever. This vaccine ranks among the best available for humans. Evidence also suggests that even smaller doses are safe and still create a good immune response. This makes the 17D vaccine a reliable choice for preventing yellow fever. Participants in this trial will receive a standard dose of the yellow fever vaccine 17D. ^{2 6 7 8 9}

Who Is on the Research Team?

William Messer, MD PhD

Principal Investigator

Oregon Health and Science University

Are You a Good Fit for This Trial?

Adults aged 20-49 who are in good health and have been previously vaccinated with the yellow fever vaccine (17D) at least 8 years ago. They must be able to follow trial procedures, provide a detailed medical history, and not plan to travel to yellow fever endemic areas during the trial.

Inclusion Criteria

I am either male or female.

I am between 20 and 49 years old.

I have an original record of a Yellow fever vaccination given over 8 years ago.

Exclusion Criteria

I am able to have children, sexually active, and haven't used birth control for 2 months.

Behavioral/cognitive impairment that, in the investigator's opinion, may interfere with the subject's ability to participate safely in the trial

I have a history of neurological disorders or seizures.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Vaccination

Participants receive a standard dose of the yellow fever vaccine 17D (YFVax®), 0.5mL suspension in normal saline administered subcutaneously once.

1 day

1 visit (in-person)

Monitoring

Participants provide blood samples approximately every other day for 14 days after vaccination and complete a daily diary of symptoms following vaccination for 14 days.

14 days

Multiple visits (in-person)

Follow-up

Participants provide a blood sample approximately 28 days after vaccination and report any additional symptoms after 14 days.

28 days

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• 17D

Trial Overview The study is testing how well adults respond to a re-vaccination of the yellow fever vaccine (17D). It looks at antibody responses and immune cell reactions after getting another dose of the same vaccine they received before.

How Is the Trial Designed?

Group I: Vaccination arm Experimental Treatment 1 Intervention

Participants will receive a standard dose of of the yellow fever vaccine 17D (YFVax(r)), 0.5mL suspension in normal saline administered subcutaneously once.

Who Is Running the Clinical Trial?

Oregon Health and Science University

Lead Sponsor

Trials

1,024

Recruited

7,420,000+

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8648041/

Comparing immunogenicity and protective efficacy of the ... The live-attenuated yellow fever 17D (YF17D) vaccine is one of the most efficacious human vaccines and also employed as a vector for novel vaccines.

2. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/34792431/

Comparing immunogenicity and protective efficacy of the ... The live-attenuated yellow fever 17D (YF17D) vaccine is one of the most efficacious human vaccines and also employed as a vector for novel vaccines.

3. thelancet.com thelancet.com/journals/laninf/article/PIIS1473-3099(23)00114-7/fulltext

Immunogenicity and safety of fractional doses of 17D-213 ... Evidence indicates that fractional doses of yellow fever vaccine are safe and sufficiently immunogenic for use during yellow fever outbreaks ...

4. fda.gov fda.gov/media/76015/download

YF-VAX® - Yellow Fever Vaccine Comparative safety and immunogenicity of two yellow fever 17D vaccines (ARILVAX and YF-VAX) in a Phase III multicenter, double-blind clinical trial. Am J ...

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1473309923001317

Immunogenicity and safety of fractional doses of 17D-213 ... Although fractional doses of all WHO-prequalified yellow fever vaccines have been shown to be safe and immunogenic in a randomised controlled trial in adults, ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4635904/

Serious adverse events associated with yellow fever vaccine Yellow fever vaccine was considered one of the safest vaccines, but in recent years it was found that it could rarely cause invasive and disseminated disease.

7. cdc.gov cdc.gov/yellow-fever/hcp/vaccine/index.html

Yellow Fever Vaccine Information for Healthcare Providers Reactions to yellow fever vaccine are generally mild and include headaches, myalgias, and low-grade pyrexia. There have been reports of rare but ...

8. who.int who.int/groups/global-advisory-committee-on-vaccine-safety/topics/yellow-fever-vaccines/safety

Safety Altogether, 14 (61%) of the 23 cases have been fatal. All cases were reported after the primary yellow fever vaccination. Recent risk estimates for yellow fever ...

9. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3269291/

The Safety of Yellow Fever Vaccine 17D or 17DD in Children ... Yellow fever vaccination very rarely causes severe adverse neurologic, multisystem, or anaphylaxis reactions.