KIGALI, Dec 6 (Reuters) - South Africa"s Biovac Institute will start making Pfizer-BioNTech"s (PFE.N), (22UAy.DE) COVID-19 vaccine early next year after receiving the drug substance from Europe, a Pfizer executive said on Monday. Biovac"s "fill and finish" deal with Pfizer, announced in July, will make it one of the few companies processing COVID-19 shots in Africa, where many countries have struggled to access sufficient doses during the pandemic. read more "We expect that the Cape Town facility will be incorporated into our supply chain by the end of this year," Patrick van der Loo, Pfizer regional president for Africa and the Middle East, told a conference in Kigali on vaccine manufacturing in Africa. "Biovac will obtain the drug substance from facilities in Europe and manufacturing of finished doses will commence early in 2022," he said, appearing by video link. Large Western pharmaceutical companies including Pfizer have been widely criticised for not doing enough to facilitate vaccine production in developing countries. In July Pfizer"s CEO urged World Trade Organization members not to support a waiver on some intellectual property rights for COVID-19 vaccines - a proposal by South Africa and India. read more Biovac"s deal with Pfizer covers the final stages of manufacturing, where the vaccine is processed and put into vials, but does not represent a transfer of the intellectual property underpinning the vaccine. Van der Loo listed what he described as historical challenges faced by pharmaceutical companies on the continent, saying these explained the difficulties in kickstarting local vaccine manufacturing. Among them were irregular power and water supplies, which have been an issue in South Africa over the years. "Last year ... water was rationed, which made it very difficult both practically but also ethically to obtain and use large quantities of water for trial runs through the equipment as part of our start-up tech transfer phase," he said, referring to operations at the Biovac facility.