Confirmed, suspected, or asymptomatic COVID-19 case Candidate with a history of SARS-CoV-2 infection (documented rtPCR) after receiving the second dose of COVID-19 vaccine. During the period of home quarantine due to Covid-19 (suspicion of exposure or suspicious symptoms). In the 14 days prior to vaccination: fever or presence of at least two symptoms from Dry cough, severe fatigue, nasal congestion, runny nose, sore throat, myalgia, diarrhoea, dyspnea, and shortness of breath History of severe allergic reaction, urticaria or allergic reactions to COVID-19 Inactivated vaccine ingredients (allergic to Aluminium). Personal or family history of seizure, epilepsy, encephalopathy or psychiatric disorders Presence of congenital malformations or any genetic disorder Presence of any malignancy Known case of immunodeficiency, HIV, lymphoma, leukemia, or other autoimmune diseases. Receiving immunosuppressive drugs or corticosteroids in the last 6 months Splenectomy or history of any organ removal History of coagulation disorders History of hereditary and acquired angioedema over the past year Receiving Anti-TB treatment Positive HBsAg/ Positive HCV antibody Receiving immunomodulators or immunosuppressors at least for14 days in the past 3 months Receiving live vaccine in one month or other vaccines in 14 days before inoculation Receiving immunoglobulins or blood products in 3 months before inoculation History of severe mental disorders affecting the participation in the study Women with a positive pregnancy test (Beta HCG in a blood sample) or breastfeeding or those who intend to become pregnant during the study period. Any other circumstances are other than the above-mentioned ones that the researcher deems inappropriate for a person participating in a clinical trial. These cases are recorded as the reason for not entering.

Confirmed, suspected, or asymptomatic COVID-19 case Candidate with a history of SARS-CoV-2 infection (documented rtPCR) after receiving the second dose of COVID-19 vaccine. During the period of home quarantine due to Covid-19 (suspicion of exposure or suspicious symptoms). In the 14 days prior to vaccination: fever or presence of at least two symptoms from Dry cough, severe fatigue, nasal congestion, runny nose, sore throat, myalgia, diarrhoea, dyspnea, and shortness of breath History of severe allergic reaction, urticaria or allergic reactions to COVID-19 Inactivated vaccine ingredients (allergic to Aluminium). Personal or family history of seizure, epilepsy, encephalopathy or psychiatric disorders Presence of congenital malformations or any genetic disorder Presence of any malignancy Known case of immunodeficiency, HIV, lymphoma, leukemia, or other autoimmune diseases. Receiving immunosuppressive drugs or corticosteroids in the last 6 months Splenectomy or history of any organ removal History of coagulation disorders History of hereditary and acquired angioedema over the past year Receiving Anti-TB treatment Positive HBsAg/ Positive HCV antibody Receiving immunomodulators or immunosuppressors at least for14 days in the past 3 months Receiving live vaccine in one month or other vaccines in 14 days before inoculation Receiving immunoglobulins or blood products in 3 months before inoculation History of severe mental disorders affecting the participation in the study Women with a positive pregnancy test (Beta HCG in a blood sample) or breastfeeding or those who intend to become pregnant during the study period. Any other circumstances are other than the above-mentioned ones that the researcher deems inappropriate for a person participating in a clinical trial. These cases are recorded as the reason for not entering.