RIYADH — Saudi Arabia's Ministry of Health announced on Wednesday the rescheduling of coronavirus vaccine administration for those who have obtained the appointment for receiving the first dose of the Pfizer vaccine. In a statement on its Twitter account, the ministry attributed this to the manufacturer's delay in supplying the vaccine to the Kingdom. Describing as an "important clarification," the ministry statement said that Pfizer Company has delayed the supply of the vaccine to all countries, including Saudi Arabia, to where it is exporting the vaccine as the company is upgrading the production capacity. A spokesman of the company last month said that Pfizer is upscaling production at its plant in Puurs, Belgium, which "presupposes adaptation of facilities and processes at the factory which requires new quality tests and approvals from the authorities." Saudi Arabia started the registration for receiving the Pfizer vaccine on Dec. 15 following the approval of the Pfizer vaccine by the Saudi Food and Drug Authority. Subsequently, the Kingdom started the nationwide vaccination campaign on Dec. 17, by opening the first vaccination center in Riyadh. Vaccination centers were opened in other major cities of Jeddah, Dammam, and Madinah later. The fifth center will be opened in Makkah this week. The ministry officials stated that vaccination centers will be opened in all the regions over the coming weeks. Meanwhile, the ministry has approved two more coronavirus vaccines — AstraZeneca and Moderna — after the success of the Pfizer vaccine, according to reports.