RecruitingPhase 1

A Study to Learn About a Vaccine Against E Coli in Healthy Adults

United States310 participantsStarted 2025-08-11

Plain-language summary

This study evaluates an investigational vaccine designed to protect against Escherichia coli (E coli). The primary objective is to assess the safety and tolerability of E coli vaccines administered intramuscularly to healthy adults.

Who can participate

Age range

18 Years – 64 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Adult Participants \>= 18 through \< 64 years of age at the time of enrollment.
. Healthy participants as determined by medical history, physical examination, and clinical judgement of the investigator to be eligible for inclusion in the study.

Exclusion criteria

. Severe adverse reaction history associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
. Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
. Women who are pregnant, plan to become pregnant during the study, or are breastfeeding.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Percentage of participants reporting prespecified local events within 7 days following each vaccination

Timeframe: 7 days after each vaccination

Percentage of participants reporting prespecified systemic events within 7 days following each vaccination

Timeframe: 7 days after each vaccination

Percentage of participants reporting Adverse Events (AEs) from vaccination 1 through 1 month after the last dose of study intervention

Timeframe: From signing of ICD to 1 month after the last assigned vaccination

Percentage of participants reporting Medically Attended Adverse Events (MAEs) from vaccination 1 through 12 months after the last dose of study intervention

Timeframe: Baseline up to month 18 with final visit being 12 months after last assigned vaccination

Percentage of participants reporting Serious Adverse Events (SAEs) from vaccination 1 through 12 months after the last dose of study intervention

Timeframe: Baseline up to month 18 with final visit being 12 months after last assigned vaccination

Trial details

NCT IDNCT07122986

SponsorPfizer

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2028-05-26

Contact for this trial

Pfizer CT.gov Call Center

1-800-718-1021 ClinicalTrials.gov_Inquiries@pfizer.com

View on ClinicalTrials.gov More Healthy Participants trials

Who can participate

Age range

18 Years – 64 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Adult Participants \>= 18 through \< 64 years of age at the time of enrollment.
. Healthy participants as determined by medical history, physical examination, and clinical judgement of the investigator to be eligible for inclusion in the study.

Exclusion criteria

. Severe adverse reaction history associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
. Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
. Women who are pregnant, plan to become pregnant during the study, or are breastfeeding.

What they're measuring

Percentage of participants reporting prespecified local events within 7 days following each vaccination

Timeframe: 7 days after each vaccination

Percentage of participants reporting prespecified systemic events within 7 days following each vaccination

Timeframe: 7 days after each vaccination

Percentage of participants reporting Adverse Events (AEs) from vaccination 1 through 1 month after the last dose of study intervention

Timeframe: From signing of ICD to 1 month after the last assigned vaccination

Percentage of participants reporting Medically Attended Adverse Events (MAEs) from vaccination 1 through 12 months after the last dose of study intervention

Timeframe: Baseline up to month 18 with final visit being 12 months after last assigned vaccination

Percentage of participants reporting Serious Adverse Events (SAEs) from vaccination 1 through 12 months after the last dose of study intervention

Timeframe: Baseline up to month 18 with final visit being 12 months after last assigned vaccination