Solicited adverse reactions (ARs) (local and systemic) were collected in the electronic diary (eDiary). Local ARs included: injection site pain, injection site erythema, and injection site induration/swelling. Systemic ARs included: body temperature (oral), generalized myalgia (muscle ache or pain), generalized arthralgia (joint ache or pain), headache, fatigue/malaise (unusual tiredness), nausea/vomiting, chills, and rash. Data for this outcome measure is reported up to 7 days after the first study vaccination only. A summary of all serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is in Reported "Adverse Events" section.

Solicited adverse reactions (ARs) (local and systemic) were collected in the electronic diary (eDiary). Local ARs included: injection site pain, injection site erythema, and injection site induration/swelling. Systemic ARs included: body temperature (oral), generalized myalgia (muscle ache or pain), generalized arthralgia (joint ache or pain), headache, fatigue/malaise (unusual tiredness), nausea/vomiting, chills, and rash. Data for this outcome measure is reported up to 7 days after the second study vaccination only. A summary of all serious AEs (SAEs) and all nonserious AEs ("Other"), regardless of causality, is in Reported "Adverse Events" section.

An unsolicited AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. The treatment-emergent AEs are defined as any event not present before exposure to study drug or any event already present that worsened in intensity or frequency after exposure. A summary of all SAEs and all nonserious AEs ("Other") reported up to the end of the study, regardless of causality, is located in the Reported "Adverse Events" section.

An MAAE is an AE that leads to an unscheduled visit to an healthcare practitioner. A summary of all SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the Reported "Adverse Events" section.

An SAE was defined as any AE that resulted in death, is life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions was a congenital anomaly/birth defect, or was an important medical event. AESIs included potentially immune-mediated medical conditions (autoimmune or autoinflammatory diseases) that may have the theoretical potential for association with novel vaccines. A summary of all SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the Reported "Adverse Events" section.