A Phase 1/2, Randomized, Observer-blind, Placebo-controlled, Dose-ranging Study to Evaluate the Safety and Immunogenicity of Heptavalent mRNA-1975 (SR1-7) and Monovalent mRNA-1982 (SR1) in Parallel Against Lyme Disease in Healthy Participants 18 Through 70 Years of Age

Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)

时间窗: Up to Day 175 (7 days after each study injection)

Number of Participants With Unsolicited Adverse Events (AEs)

时间窗: Up to Day 196 (28 days after each study injection)

Number of Participants With Medically Attended AEs

时间窗: Day 1 through Day 337 (6 months after the last study injection)

Number of Participants with AEs of Special Interest, Serious AEs, and AEs Leading to Discontinuation of Study Injection or Study Participation

时间窗: Day 1 through Day 505 (End of Study)

Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) Within 7 Days After Day 1 Injection

时间窗: Up to 7 days after Day 1 injection

Solicited ARs were collected in an electronic diary (eDiary). Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered adverse events (AEs). Investigator reviewed whether the solicited AR was also to be recorded as an AE. A summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

Number of Participants With Solicited Local and Systemic ARs Within 7 Days After Day 57 Injection

时间窗: Up to 7 days after Day 57 injection

Solicited ARs were collected in an eDiary. Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered AEs. Investigator reviewed whether the solicited AR was also to be recorded as an AE. A summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

Number of Participants With Solicited Local and Systemic ARs Within 7 Days After Day 169 Injection

时间窗: Up to 7 days after Day 169 injection

Solicited ARs were collected in an eDiary. Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered AEs. Investigator reviewed whether the solicited AR was also to be recorded as an AE. A summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

Number of Participants With Unsolicited AEs

时间窗: Up to 28 days post any injection

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or prothrombin time \[PT\]/partial thromboplastin time \[PTT\]) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

Number of Participants With Medically Attended AEs (MAAEs), Adverse Events of Special Interest (AESIs), SAEs, and AEs Leading to Study Discontinuation

时间窗: Day 1 up to Month 18

A MAAE is an AE that led to an unscheduled visit to a healthcare practitioner. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. An AESI was an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor were required. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.