inclusion criteria: - persons who have received a dose of gam-covid-vac more than 30 days and: - age > 21 and <66 years. - both genders. - who have voluntarily agreed to participate in the clinical trial and have provided informed consent.

inclusion criteria: - persons who have received a dose of gam-covid-vac more than 30 days and: - age > 21 and <66 years. - both genders. - who have voluntarily agreed to participate in the clinical trial and have provided informed consent.