Age 18 years and older Candidates who have received two identical doses of the available vaccine (Sinopharm, CovIran Barakat, AstraZenka) and at least 3 months (at least 90 days) have passed since the second dose The candidate is able to fully understand the provisions of the informed consent form and sign it before entering the study

Age 18 years and older Candidates who have received two identical doses of the available vaccine (Sinopharm, CovIran Barakat, AstraZenka) and at least 3 months (at least 90 days) have passed since the second dose The candidate is able to fully understand the provisions of the informed consent form and sign it before entering the study