Flu vaccine study halted after just 2 volunteers

NCT ID NCT07386509

What the study statuses mean

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Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early This study
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study aimed to compare how the immune system responds to two different seasonal flu vaccines given at the same time. Healthy adults aged 18-49 who had not received a flu shot in at least three years were eligible. The study was terminated early and only enrolled 2 participants, so no meaningful conclusions can be drawn.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Early phase 1

The earliest testing in people: a first look at safety, in a very small group.

Participants

2 people

The number who actually took part.

Started

Mar 2020

Finished

Nov 2022

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 to 49 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 1\. Healthy subjects aged 18-49 years. 2. Able to understand and give informed consent. 3. Women of child-bearing potential (not surgically sterile via tubal ligation, bilateral oophorectomy or hysterectomy or who are not postmenopausal for ≥1 year) must agree to practice adequate contraception that may include, but is not limited to, abstinence, monogamous relationship with vasectomized partner, barrier methods such as condoms, diaphragms, spermicides, intrauterine devices, and licensed hormonal methods\* for 28 days before and 28 days after rabies vaccination. * Women of child-bearing potential using licensed hormonal methods must also use a second form of contraception. 4\. Are in good health, as determined by medical history and targeted physical exam related to this history. 5\. Willing to give FNA specimens for the study. 6\. The following laboratory values obtained within 14 days prior to entry by any US laboratory that has a CLIA certification or its equivalent. • Absolute neutrophil count (ANC) ≥750 cells/mm3 • Hemoglobin ≥11.0 g/dL for men and ≥10.0 g/dL for women * Platelet count ≥100,000/mm3 * Creatinine clearance ≥60 mL/min estimated by the Cockcroft-Gault equation * NOTE: A program for calculating creatinine clearance by the Cockcroft-Gault method is available on www.fstrf.org * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (SGPT) ≤5.0 times upper limit of normal (ULN) * Erythrocyte sedimentation rate (ESR) within normal range Exclusion Criteria: * 1\. Receipt of the following: * Receipt of blood products 3 months prior to vaccination or expected receipt through 12 months after vaccination. * Receipt of any live virus vaccines within 28 days prior to vaccination or expected receipt within 28 days after vaccination. \* * Receipt of any inactivated vaccine within 14 days or expected receipt within 14 days after vaccination other than study vaccine. \* 2. Presence of co-morbidities or immunosuppressive states such as: Chronic medical problems including (but not limited to) insulin dependent diabetes, severe heart disease (including arrhythmias), severe lung disease, auto immune diseases, thrombocytopenia and any other severe medical conditions. 3\. Alcohol abuse, drug abuse, or psychiatric conditions that in the opinion of the investigator would preclude compliance with the trial or interpretation of safety or endpoint data. 4\. Any history of lymphoma involving axillary nodes or any history of breast cancer. 5\. Impaired immune function or known chronic infections including, but not limited to, known HIV, tuberculosis, hepatitis B or C; organ transplantation (bone marrow, hematopoietic stem cell, or solid organ transplant); immunosuppression due to cancer; current and/or expected receipt of chemotherapy, radiation therapy, steroids\*\* (i.e., more than 20 mg of prednisone given daily or on alternative days for 2 weeks or more in the past 90 days , or high dose inhaled corticosteroids\*\*\*); and any other immunosuppressive therapies (including anti-TNF therapy), functional or anatomic asplenia, or congenital immunodeficiency. 6\. Pregnancy or breast feeding 7. Conditions that could affect the safety of the volunteers, such as: * Severe reactions to prior vaccinations, including anaphylaxis * History of Guillain-Barré syndrome * History of bleeding disorders or current use of warfarin, aspirin, heparin, nonsteroidal anti-inflammatory drugs (NSAIDs) or other blood thinner/anticoagulant medications in the past week * Any allergy to any component of the vaccine or lidocaine 8. Subjects with any acute illness, including any fever (\> 100.4 F \[\>38.0C\], regardless of the route) within 3 days prior to vaccination \*. 9\. Social, occupational, or any other condition that in the opinion of the investigator might interfere with compliance with the study and vaccine evaluation. 10\. ESR\>30 mm/hour. 11. Previously received the 2019-2020 influenza vaccine. 12. Bilateral inflammatory process of upper arms in the past 2 weeks. 13. Prior breast or axillary biopsy and/or surgery. Notes: * An individual who initially is excluded from study participation based on one or more of the time-limited exclusion criteria (e.g., acute illness, receipt or expected receipt of live or inactivated vaccines) may be reconsidered for enrollment once the condition has resolved as long as the subject continues to meet all other entry criteria. * Subjects receiving \> 20 mg/day of prednisone or its equivalent daily or on alternate days for more than 2 weeks may enter the study after therapy has been discontinued for more than 3 months. * Subjects are excluded if on high dose intranasal steroids defined as \> 960 mcg/day of beclomethasone dipropionate or equivalent.

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Washington University School of Medicine Infectious Disease Clinical Trials Unit.

    St Louis, Missouri, 63110, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.