* have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. * have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. * had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. * had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. * had any vaccination within the 28 days prior to visit 0. * had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. * had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. * have a known history of active or ongoing hepatitis b or hepatitis c infection; or except for cohort 13: hiv-1 or hiv-2 infection within the 30 days prior to visit 0. * have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. * have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. * have a positive breath alcohol test at visit 0 or visit 1. * previously participated in an investigational trial involving lipid nanoparticles. * are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments; subjects immunized with bnt162 vaccines in this clinical trial are allowed to participate in other clinical trials involving immunization with bnt162b2. * have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). * have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * have a history of hypersensitivity or serious reactions to previous vaccinations. * have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. * have a history of narcolepsy. * have history of alcohol abuse or drug addiction within 1 year before visit 0. * (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. * have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. * have had any blood loss \>450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. * have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. * have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. * are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. * regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). * for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: * uncontrolled hypertension. * diabetes mellitus (hba1c \>8.5% ≥3 months, according to the medical history reported by the subject). * chronic obstructive pulmonary disease. * asthma. * chronic liver disease. * known stage 3 or worse chronic kidney disease (glomerular filtration rate \<60 ml/min/1.73 m\^2); except for post-renal transplant patients who should have (estimated) gfr ≥40 ml/min/1.73 m\^2. * serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. * sickle cell disease. * cancer (except for cohort 13). * are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. * are immune compromised due to hiv infection with a cd4+ count of \< 200 x 10\^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. * resident in a long term facility. * current vaping or smoking (occasional smoking is acceptable). * history of chronic smoking within the prior year.

* have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. * have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. * had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. * had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. * had any vaccination within the 28 days prior to visit 0. * had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. * had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. * have a known history of active or ongoing hepatitis b or hepatitis c infection; or except for cohort 13: hiv-1 or hiv-2 infection within the 30 days prior to visit 0. * have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. * have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. * have a positive breath alcohol test at visit 0 or visit 1. * previously participated in an investigational trial involving lipid nanoparticles. * are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments; subjects immunized with bnt162 vaccines in this clinical trial are allowed to participate in other clinical trials involving immunization with bnt162b2. * have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). * have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. * have a history of hypersensitivity or serious reactions to previous vaccinations. * have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. * have a history of narcolepsy. * have history of alcohol abuse or drug addiction within 1 year before visit 0. * (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. * have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. * have had any blood loss \>450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. * have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. * have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. * are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. * regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). * for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: * uncontrolled hypertension. * diabetes mellitus (hba1c \>8.5% ≥3 months, according to the medical history reported by the subject). * chronic obstructive pulmonary disease. * asthma. * chronic liver disease. * known stage 3 or worse chronic kidney disease (glomerular filtration rate \<60 ml/min/1.73 m\^2); except for post-renal transplant patients who should have (estimated) gfr ≥40 ml/min/1.73 m\^2. * serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. * sickle cell disease. * cancer (except for cohort 13). * are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. * are immune compromised due to hiv infection with a cd4+ count of \< 200 x 10\^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. * resident in a long term facility. * current vaping or smoking (occasional smoking is acceptable). * history of chronic smoking within the prior year.

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. - had any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history of active or ongoing hepatitis b or hepatitis c infection; or except for cohort 13: hiv-1 or hiv-2 infection within the 30 days prior to visit 0. - have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments; subjects immunized with bnt162 vaccines in this clinical trial are allowed to participate in other clinical trials involving immunization with bnt162b2. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). - for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - uncontrolled hypertension. - diabetes mellitus (hba1c >8.5% ≥3 months, according to the medical history reported by the subject). - chronic obstructive pulmonary disease. - asthma. - chronic liver disease. - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2); except for post-renal transplant patients who should have (estimated) gfr ≥40 ml/min/1.73 m^2. - serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. - sickle cell disease. - cancer (except for cohort 13). - are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. - are immune compromised due to hiv infection with a cd4+ count of < 200 x 10^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. - resident in a long term facility. - current vaping or smoking (occasional smoking is acceptable). - history of chronic smoking within the prior year.

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. - had any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history of active or ongoing hepatitis b or hepatitis c infection; or except for cohort 13: hiv-1 or hiv-2 infection within the 30 days prior to visit 0. - have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments; subjects immunized with bnt162 vaccines in this clinical trial are allowed to participate in other clinical trials involving immunization with bnt162b2. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). - for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - uncontrolled hypertension. - diabetes mellitus (hba1c >8.5% ≥3 months, according to the medical history reported by the subject). - chronic obstructive pulmonary disease. - asthma. - chronic liver disease. - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2); except for post-renal transplant patients who should have (estimated) gfr ≥40 ml/min/1.73 m^2. - serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. - sickle cell disease. - cancer (except for cohort 13). - are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. - are immune compromised due to hiv infection with a cd4+ count of < 200 x 10^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. - resident in a long term facility. - current vaping or smoking (occasional smoking is acceptable). - history of chronic smoking within the prior year.

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. - had any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history or a positive test for any of hepatitis b, or hepatitis c, or hiv 1 or 2 (except for cohort 13) within the 30 d prior to visit 0. - have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). - for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - hypertension. - diabetes mellitus. - chronic obstructive pulmonary disease. - asthma. - chronic liver disease. - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2). - serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. - sickle cell disease. - cancer (except for cohort 13). - are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. - are immune compromised due to hiv infection with a cd4+ count of < 200 x 10^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. - resident in a long term facility. - current vaping or smoking (occasional smoking is acceptable). - history of chronic smoking within the prior year.

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs (except for cohort 13), within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. note: healthy volunteers with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included. - had any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history or a positive test for any of hepatitis b, or hepatitis c, or hiv 1 or 2 (except for cohort 13) within the 30 d prior to visit 0. - have a positive polymerase chain reaction (pcr)-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. when entering the follow-up phase, i.e., after completing the end of treatment (eot) visit, subjects are allowed to participate in other clinical trials not investigating covid-19 vaccines or treatments. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - (except for cohort 13) have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - have symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, volunteers in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids (except for cohort 13). - for older volunteers and for cohort 13 only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - hypertension. - diabetes mellitus. - chronic obstructive pulmonary disease. - asthma. - chronic liver disease. - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2). - serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies. - sickle cell disease. - cancer (except for cohort 13). - are immune compromised due to stem cell or organ-transplantation with significant medical complications such as acute or chronic graft rejection or graft versus host disease requiring intensive immunosuppressive treatment, transplant failure or infectious complications or other conditions that would be considered a contraindication for vaccination. - are immune compromised due to hiv infection with a cd4+ count of < 200 x 10^6 /l at screening or significant medical complications such as opportunistic infections, malignant complications (e.g., lymphoma, kaposi sarcoma), other organ manifestations consistent with advanced aids or other conditions that would be considered a contraindication for vaccination. - resident in a long term facility. - current vaping or smoking (occasional smoking is acceptable). - history of chronic smoking within the prior year.

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs, within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. - received any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history or a positive test of any of human immunodeficiency virus (hiv) 1 or 2, hepatitis b, or hepatitis c, within the 30 days prior to visit 0. - have a positive polymerase chain reaction-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, subjects in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids. - for older adults only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - hypertension - diabetes mellitus - chronic pulmonary disease - asthma - chronic liver disease - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2) - anticipating the need for immunosuppressive treatment within the next 6 months - resident in a long-term facility - current vaping or smoking (occasional smoking is acceptable) - history of chronic smoking within the prior year

- have had any acute illness, as determined by the investigator, with or without fever, within 72 hours prior to the first immunization. an acute illness which is nearly resolved with only minor residual symptoms remaining is allowable if, in the opinion of the investigator, the residual symptoms will not compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - are breastfeeding on the day of visit 0 or who plan to breastfeed during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - have a known allergy, hypersensitivity, or intolerance to the planned investigational medicinal product (imp) including any excipients of the imp. - had any medical condition or any major surgery (e.g., requiring general anesthesia) within the past 5 years which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have any surgery planned during the trial, starting after visit 0 and continuously until at least 90 days after receiving the last immunization. - had any chronic use (more than 21 continuous days) of any systemic medications, including immunosuppressant's or other immune-modifying drugs, within the 6 months prior to visit 0 unless in the opinion of the investigator, the medication would not prevent, limit, or confound the protocol-specified assessments or could compromise subject safety. - received any vaccination within the 28 days prior to visit 0. - had administration of any immunoglobulins and/or any blood products within the 3 months prior to visit 0. - had administration of another investigational medicinal product including vaccines within 60 days or 5 half-lives (whichever is longer), prior to visit 0. - have a known history or a positive test of any of human immunodeficiency virus (hiv) 1 or 2, hepatitis b, or hepatitis c, within the 30 days prior to visit 0. - have a positive polymerase chain reaction-based test for sars-cov-2 within the 30 days prior to visit 1. - have a positive drugs of abuse (for amphetamines, benzodiazepines, barbiturates, cocaine, cannabinoids, opiates, methadone, methamphetamines, phencyclidine, and tricyclic antidepressants) result at visit 0 or visit 1. - have a positive breath alcohol test at visit 0 or visit 1. - previously participated in an investigational trial involving lipid nanoparticles. - are subject to exclusion periods from other investigational trials or simultaneous participation in another clinical trial. - have any affiliation with the trial site (e.g., are close relative of the investigator or dependent person, such as an employee or student of the trial site). - have a history (within the past 5 years) of substance abuse or known medical, psychological, or social conditions which, in the opinion of the investigator, could compromise their well-being if they participate as trial subjects in the trial, or that could prevent, limit, or confound the protocol-specified assessments. - have a history of hypersensitivity or serious reactions to previous vaccinations. - have a history of guillain-barré syndrome within 6 weeks following a previous vaccination. - have a history of narcolepsy. - have history of alcohol abuse or drug addiction within 1 year before visit 0. - have a history of or suspected immunosuppressive condition, acquired or congenital, as determined by medical history and/or physical examination at visit 0. - have any abnormality or permanent body art (e.g., tattoo) that, in the opinion of the investigator, would obstruct the ability to observe local reactions at the injection site. - have had any blood loss >450 ml, e.g., due to donation of blood or blood products or injury, within the 7 days prior to visit 0 or plan to donate blood during the trial, starting after visit 0 and continuously until at least 7 days after receiving the last immunization. - symptoms of covid-19, e.g., respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. - have had contact with persons diagnosed with covid-19 or who tested positive for sars-cov-2 by any diagnostic test within the 30 days prior to visit 1. - are soldiers, subjects in detention, contract research organization (cro) or sponsor staff or their family members. - regular receipt of inhaled/nebulized corticosteroids. - for older adults only: have a condition known to put them at high risk for severe covid-19, including those with any of the following risk factors: - hypertension - diabetes mellitus - chronic pulmonary disease - asthma - chronic liver disease - known stage 3 or worse chronic kidney disease (glomerular filtration rate <60 ml/min/1.73 m^2) - anticipating the need for immunosuppressive treatment within the next 6 months - resident in a long-term facility - current vaping or smoking (occasional smoking is acceptable) - history of chronic smoking within the prior year