<Group 1> Group who are 20 to under 65 years and finished two intramuscular injections of Pfizer Comirnaty1. Subjects who are 20 years old or older and under 65 years old at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 2> Group who are 65 years or older and finished two intramuscular injections of Pfizer Comirnaty1. Subjects aged 65 and over at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 3> Group who are 20 to under 65 years and finished two intramuscular injections of Takeda/Moderna vaccine1. Subjects who are 20 years old or older and under 65 years old at the time of obtaining consent2. Subjects who have been vaccinated twice with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 4> Group who are 65 years or older and finished two intramuscular injections of Takeda/Moderna vaccine1. Subjects aged 65 and over at the time of obtaining consent2. Subjects who have been vaccinated twice with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 5-1> Group who have been vaccinated with Pfizer Comirnaty intramuscular injection only once1. Subjects who are 20 years old or older at the time of obtaining consent2. Subjects who have been vaccinated once with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 5-2> Group who have been vaccinated with Takeda/Moderna vaccine intramuscular injection only once1. Subjects who are 20 years old or older at the time of obtaining consent2. Subjects who have been vaccinated once with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 6-1> Group who have been vaccinated with Pfizer Comirnaty intramuscular injection twice with a history of SARS-CoV-2 infection 1. Those who are 20 years of age or older at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection have been vaccinated for 6 to 12 mon

<Group 1> Group who are 20 to under 65 years and finished two intramuscular injections of Pfizer Comirnaty1. Subjects who are 20 years old or older and under 65 years old at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 2> Group who are 65 years or older and finished two intramuscular injections of Pfizer Comirnaty1. Subjects aged 65 and over at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 3> Group who are 20 to under 65 years and finished two intramuscular injections of Takeda/Moderna vaccine1. Subjects who are 20 years old or older and under 65 years old at the time of obtaining consent2. Subjects who have been vaccinated twice with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 4> Group who are 65 years or older and finished two intramuscular injections of Takeda/Moderna vaccine1. Subjects aged 65 and over at the time of obtaining consent2. Subjects who have been vaccinated twice with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the first vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 5-1> Group who have been vaccinated with Pfizer Comirnaty intramuscular injection only once1. Subjects who are 20 years old or older at the time of obtaining consent2. Subjects who have been vaccinated once with Pfizer Comirnaty intramuscular injection before receiving this investigational drug and 6-12 months have passed since the vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 5-2> Group who have been vaccinated with Takeda/Moderna vaccine intramuscular injection only once1. Subjects who are 20 years old or older at the time of obtaining consent2. Subjects who have been vaccinated once with Takeda/Moderna vaccine intramuscular injection before receiving this investigational drug and 6-12 months have passed since the vaccine.3. Subjects with no apparent history of SARS-CoV-2 infection prior to inoculation of this investigational drug4. Subjects who can obtain written consent<Group 6-1> Group who have been vaccinated with Pfizer Comirnaty intramuscular injection twice with a history of SARS-CoV-2 infection 1. Those who are 20 years of age or older at the time of obtaining consent2. Subjects who have been vaccinated twice with Pfizer Comirnaty intramuscular injection have been vaccinated for 6 to 12 mon