inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: 1. pediatric participants 6 months to \< 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs \[to include body temperature\], medical history, and targeted physical examination \[to include body weight\]). vital signs must be within the normal range prior to the first vaccination, according to the child's age, sex, weight, and height/length. 2. for children from 6 months to \< 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). 3. participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. 4. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile \[ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy\]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. 5. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.

inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: 1. pediatric participants 6 months to \< 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs \[to include body temperature\], medical history, and targeted physical examination \[to include body weight\]). vital signs must be within the normal range prior to the first vaccination, according to the child's age, sex, weight, and height/length. 2. for children from 6 months to \< 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). 3. participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. 4. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile \[ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy\]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. 5. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.

inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: pediatric participants 6 months to < 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). vital signs must be within the normal range prior to the first vaccination, according to the child's age, sex, weight, and height/length. for children from 6 months to < 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.

inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: pediatric participants 6 months to < 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). vital signs must be within the normal range prior to the first vaccination, according to the child's age, sex, weight, and height/length. for children from 6 months to < 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.

inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: pediatric participants 6 months to < 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). vital signs must be within normal range prior to the first vaccination, according to the child's age, sex, and height. for children from 6 months to < 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.

inclusion criteria: to be included in this study, each individual must satisfy all of the following criteria: pediatric participants 6 months to < 12 years of age at randomization, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). vital signs must be within normal range prior to the first vaccination, according to the child's age, sex, and height. for children from 6 months to < 12 months of age: born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures. participants of childbearing potential (defined as any participant who has experienced menarche and who is not surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination or agree to consistently use a highly effective contraception method from at least 28 days prior to enrollment and through 3 months after the last vaccination. agree not to participate in another sars-cov-2 prevention trial for the duration of the study.