inclusion criteria: - male or female participants 18 - 55 years of age, inclusive, at visit 1, (day 1). - participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. - healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study. note: healthy participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrolment, can be included. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the icd and in the protocol. - for dose 3: participants who received both doses of the lyophilized formulation of bnt162b2 as part of the initial study.

inclusion criteria: - male or female participants 18 - 55 years of age, inclusive, at visit 1, (day 1). - participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. - healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study. note: healthy participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrolment, can be included. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the icd and in the protocol. - for dose 3: participants who received both doses of the lyophilized formulation of bnt162b2 as part of the initial study.

inclusion criteria: - male or female participants 18 - 55 years of age, inclusive, at visit 1, (day 1). - participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. - healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study. note: healthy participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrolment, can be included. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the icd and in the protocol.

inclusion criteria: - male or female participants 18 - 55 years of age, inclusive, at visit 1, (day 1). - participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. - healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study. note: healthy participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrolment, can be included. - capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the icd and in the protocol.