A Study of Safety and Immune Response to Different Doses of a Cytomegalovirus Vaccine in Healthy Adults

Inclusion Criteria: * Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol. * Written informed consent obtained from the participant prior to performance of any study specific procedure. * A healthy adult (woman or man), 18 to 50 years of age at the time of the first study intervention administration. * Healthy participants as established by medical history and clinical examination before entering the study. * Participants who are women of non-childbearing potential may be enrolled in the study. * Participants who are women of child-bearing potential may be enrolled in the study, if the participant: * has practiced adequate contraception for 30 days prior to study intervention administration, and * has a negative pregnancy test on the day of study intervention administration and * has agreed to continue adequate contraception during the entire treatment period and for 3 months after completion of the study intervention administration series. * Participants who agree to take appropriate infection control measures to prevent becoming infected with SARS-CoV2 during the study. * Participants who initially fail screening due to COVID-19 infection may be re-screened and included in the study, within the screening window period. * Participants with signs/symptoms suggestive of active COVID-19 (i.e., fever, cough, etc.) should be isolated for the time period recommended by CDC since the signs/symptoms started, and sym…