COVID-19 biorepository is a longitudinal disease-based cohort study. Eligible to participate were all patients with a laboratory diagnosis of COVID-19 (including children and pregnant women). In total, around 2,000 COVID-19 participants were recruited and followed up for one year. The follow-up time points were weekly while consented participants were hospitalized or under isolation in quarantine facilities, and monthly follow-ups after disease recovery, for a year. Data and biological samples were collected, with access to the participants' medical records. Recruitment of the infected population is completed. COVID-19 biorepository study extends its objectives to collect information about the immunization process against SARS-CoV-2 (coronavirus) in Qatar. Consenting participants will be asked to complete a face to face questionnaire, and provide biological samples at different time points: 1) before vaccination, 2) before the second dose of the vaccine, 3) 2 to 3 weeks after the last dose of vaccine, 4) every 3 months after the last dose of the vaccine for a period of 1 year.