Inclusion Criteria:  1. Male or female participants who are ≥2 years of age at the time of enrollment (Visit 1).  2. Participants or participants' parent(s)/legal guardians, as age appropriate, who sign consent, and are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.  3. Life expectancy ≥12 months (365 days) in the opinion of the investigator at enrollment (Visit 1).  4. Participants or participant's parent(s)/legal guardians, as age appropriate, who are able to be contacted by telephone throughout the study period.  5. Female participant of childbearing potential or male participant able to father children who is willing to use a highly effective method of contraception as outlined in this protocol for at least 28 days after the last dose of study intervention if at risk of pregnancy with her/his partner; or female participant not of childbearing potential or male participant not able to father children.  6. Participants who are immunocompromised by virtue of the following:  Having known NSCLC and is ≥18 years of age with at least 1 of the following: Who received chemotherapy at least 2 weeks (14 days) before enrollment (or is treatment naïve), and is not expected to receive chemotherapy within at least 2 weeks (14 days) after dose administration; and/or Receiving checkpoint inhibitor treatment (PD-1/PD-L1 inhibitor, CTLA-4 inhibitor) and has undergone at least 1 treatment cycle prior to enrollment (at Visit 1); or Receiving targeted drug therapy treatment (EGFR, ALK, ROS1, BRAF, RET, MET, NTRK inhibitors) and has undergone at least 1 treatment cycle prior to enrollment (at Visit 1); or Having known CLL and is ≥18 years of age with at least 1 of the following: Has asymptomatic disease (eg, Rai stage <3, Binet stage A or B) and is undergoing observation and does not receive any treatment for CLL; or Receiving B-cell inhibitory monoclonal antibody treatment (anti-CD20) and has received at least 3 cycles prior to enrollment; and/or Receives a BTK inhibitor, PI3K inhibitor, or BCL-2 inhibitor OR Is currently undergoing maintenance hemodialysis treatment secondary to end-stage renal disease and is ≥18 years of age OR  Is on active immunomodulator therapy (eg, TNFα inhibitor, or tofacitinib or methotrexate) for an autoimmune or inflammatory disease disorder (eg, inflammatory arthritis, such as rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis, and inflammatory bowel disease, such as ulcerative colitis and Crohn's disease) at a stable* dose  Stable dose is defined as receiving the same dose for at least 3 months (84 days) with no changes in the 28 days prior to Visit 1.  OR  Receiving a solid organ transplant at least 3 months (84 days) prior to enrollment (Visit 1) and with no acute rejection episodes within 2 months (60 days) prior to enrollment (Visit 1), and is ≥2 to <18 years of age OR Has had an autologous or allogenic bone marrow or stem cell transplant at least 6 months (182 days) prior to enrollment (Visit 1), with adequate immune reconstitution for immunization, in the investigator's opinion, and is ≥2 to <18 years of age 7. The participant or participant's parent(s)/legal guardian is capable of giving signed informed consent, and assent (as appropriate), as described in Appendix 1, which includes compliance with the requirements and restrictions listed in the ICD and in this protocol. The investigator, or a person designated by the investigator, will obtain written informed consent (and assent, as appropriate) from each study participant or participant's parent(s)/legal guardian (as defined in Appendix 1) before any study-specific activity is performed. All parent(s)/legal guardians should be fully informed, and participants should be informed to the fullest extent possible, about the study in language and terms they are able to understand. The investigator will retain the original copy of each participant's signed consent (and assent, as appropriate) document(s).  Exclusion Criteria:  1. Past clinical (based on COVID-19 symptoms/signs alone, if a SARS CoV 2 NAAT result was not available) or microbiological (based on COVID-19 symptoms/signs and a positive SARS-CoV-2 NAAT result) diagnosis of COVID 19, or a past clinical diagnosis of MIS-C.  2. Participants with active GVHD, transplant rejection, or PTLD, or participants who have had treatment for these conditions within 3 months (84 days) prior to study enrollment (Visit 1).  3. Participants <18 years of age whose weight is less than the 5th percentile of age-adjusted ideal body weight.  4. Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.  5. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).  6. Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.  7. Participant who is pregnant or breastfeeding. 8. Participants who may be ineligible because of the number of phlebotomy assessments during this study, in the opinion of the investigator.  9. Participants who do not have adequate deltoid muscle mass to allow intramuscular vaccination, in the opinion of the investigator.  10. Previous vaccination with any coronavirus vaccine. 11. Ongoing, or history of, treatment with blood/plasma products or immunoglobulins within 3 months (84 days) prior to Dose 1 or planned receipt of these medications prior to Dose 3.  12. Participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation.  13. Previous participation in other studies involving study intervention containing LNPs.  14. Participants who are direct descendants (child or grandchild, parent or grandparent) of investigational site staff members or Pfizer/BioNTech employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.  15. Investigator site staff or Pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.