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.

Ages Eligible for Study: 18 to 64 Years (Adult) Sexes Eligible for Study: All Accepts Healthy Volunteers: Yes

Key Inclusion Criteria

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

Key Exclusion Criteria

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

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.