RIYADH — The Ministry of Health said that the appointments for taking the second COVID-19 shots can be rescheduled through the Sehhaty application in accordance with the approved days between the two doses to ensure the effectiveness of the vaccine. In response to queries on its Twitter account regarding the possibility of advancing the appointment for receiving the second dose of the vaccine, the ministry said that it can be contacted via the toll-free number (937) to receive the necessary information in this regard. The ministry had confirmed earlier that the second dose of Pfizer-BioNTech vaccine shall be taken within a period of time ranging between three and six weeks after the first dose while the duration between the first and second doses of AstraZeneca vaccine ranges between 8 and 12 weeks after receiving the first dose. Two weeks ago, the ministry announced that all citizens and expatriates at the age of 16 and above would be allowed to take coronavirus vaccine shots. “It is possible to receive the Pfizer-BioNTech COVID-19 vaccine by all those who turn the age of 16 years and above while the minimum age for administering Oxford-AstraZeneca vaccine is 18 years,” the ministry said in a statement. The ministry has designated its “Health 937” Twitter account to render medical consultations and responding to queries about health services.