individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 15 kg (33 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction \[pcr\] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) 20. medically unstable hypertension 21. current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator 22. unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator 23. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 15 kg (33 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction \[pcr\] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) 20. medically unstable hypertension 21. current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator 22. unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator 23. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol weight less than 15 kg (33 lbs) prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) history of reaction to doxil® known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination history of autoimmune or other disorders requiring systemic immune modulators history of acute urticaria within 28 days of randomization pregnant have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration have received a biologic therapy within 6 months of randomization use of systemic steroids for any reason within 28 days of randomization use of zileuton® within 14 days of randomization use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) medically unstable hypertension current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol weight less than 15 kg (33 lbs) prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) history of reaction to doxil® known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination history of autoimmune or other disorders requiring systemic immune modulators history of acute urticaria within 28 days of randomization pregnant have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration have received a biologic therapy within 6 months of randomization use of systemic steroids for any reason within 28 days of randomization use of zileuton® within 14 days of randomization use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) medically unstable hypertension current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol weight less than 36 kg (79 lbs) prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) history of reaction to doxil® known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination history of autoimmune or other disorders requiring systemic immune modulators history of acute urticaria within 28 days of randomization pregnant have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration have received a biologic therapy within 6 months of randomization use of systemic steroids for any reason within 28 days of randomization use of zileuton® within 14 days of randomization use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) medically unstable hypertension current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol weight less than 36 kg (79 lbs) prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) history of reaction to doxil® known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination history of autoimmune or other disorders requiring systemic immune modulators history of acute urticaria within 28 days of randomization pregnant have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration have received a biologic therapy within 6 months of randomization use of systemic steroids for any reason within 28 days of randomization use of zileuton® within 14 days of randomization use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) medically unstable hypertension current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 36 kg (79 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) 20. medically unstable hypertension 21. current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator 22. unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator 23. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 36 kg (79 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of any monoclonal antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. coronary artery disease, peripheral or cerebral vascular disease, unstable angina, or cardiac arrhythmia, other than supraventricular tachycardia (svt) 20. medically unstable hypertension 21. current use of beta-blockers, angiotensin-converting enzyme (ace) inhibitors, monoamine oxidase (mao) inhibitors, tricyclic anti-depressants or other agents that could interfere with the treatment of anaphylaxis, in the opinion of the investigator 22. unstable asthma within 3 months of randomization or symptomatic asthma on the day of vaccination, as assessed by the site investigator 23. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements --this includes individuals with underlying conditions or other medications that, in the opinion of the investigator, may increase risk in the event of an anaphylactic reaction or lead to complications following administration of epinephrine

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 36 kg (79 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. weight less than 36 kg (79 lbs) 3. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 4. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 5. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 6. history of reaction to doxil® 7. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 8. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 9. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 10. history of autoimmune or other disorders requiring systemic immune modulators 11. history of acute urticaria within 28 days of randomization 12. pregnant 13. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 14. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 15. have received a biologic therapy within 6 months of randomization 16. use of systemic steroids for any reason within 28 days of randomization 17. use of zileuton® within 14 days of randomization 18. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 19. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness of a participant and/or parent/legal guardian to give written informed consent and/or assent, as applicable, or to comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction [pcr] or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees fahrenheit, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness to give written informed consent or comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction (pcr) or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness to give written informed consent or comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction (pcr) or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and imdevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness to give written informed consent or comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction (pcr) or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and indevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements

individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. inability or unwillingness to give written informed consent or comply with study protocol 2. prior receipt of any doses of the pfizer-biontech coronavirus disease 2019 (covid-19) vaccine, moderna covid-19 vaccine, or any other covid-19 vaccine 3. history of a severe reaction to any component of the pfizer-biontech covid-19 vaccine or moderna covid-19 vaccine 4. history of contact dermatitis with confirmed patch test reaction to prevalence of polyethylene glycol (peg) 5. history of reaction to doxil® 6. known exposure to severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and still within the quarantine window 7. symptoms consistent with acute covid-19 infection or known covid-19 infection (positive polymerase chain reaction (pcr) or antigen test) and still within the quarantine window 8. have an acute illness, including body temperature greater than 100.4 degrees, within 14 days of the first study vaccination/placebo administration or 3 days prior to each subsequent vaccination 9. history of autoimmune or other disorders requiring systemic immune modulators 10. history of acute urticaria within 28 days of randomization 11. pregnant 12. have received any vaccines within 14 days of the first study vaccination/placebo administration or plan to receive other vaccines during the study period 13. had any allergen immunotherapy administration within 24 hours prior to vaccination/placebo administration or plan to receive within 24 hours after vaccination/placebo administration 14. have received a biologic therapy within 6 months of randomization 15. use of systemic steroids for any reason within 28 days of randomization 16. use of zileuton® within 14 days of randomization 17. use of emergency use authorization (eua) monoclonal antibodies casirivimab and indevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of covid-19 within 3 months of randomization 18. have past or current medical problems or findings from physical exam or laboratory testing not listed above, which in the opinion of the investigator, may pose additional risks from participation in the study or which may interfere with the ability to comply with study requirements