Sufficient doses of a Covid-19 vaccine may be available only towards the end of next year, the Ministry of Health's director of medical services Kenneth Mak has said.

He also said Singapore is proactively working with vaccine developers, pharmaceutical firms and research institutions on finding a vaccine for Covid-19.

Discussions have begun to ensure Singapore will have access to vaccines when they become available, he told a virtual press conference yesterday.

Although a number of companies have announced that they have started phase three trials, which are a "relatively later stage" of the process of vaccine development, there may yet be failures in delivering a vaccine that is safe and effective, said Associate Professor Mak.

"Practically speaking, we expect, realistically, a vaccine to be available perhaps next year rather than this year," he said.

"Given the global demand for these vaccines, it may not even be in the beginning of next year but perhaps towards the end of next year, where we might see vaccines produced in sufficient doses, and available for procurement and to be delivered to Singapore."

Currently, it is still not known which of the vaccine candidates undergoing trials will ultimately be the one most likely to be brought into and used in Singapore, he said.

"We continue to work at making sure we have access to those vaccines," he added.

Health Minister Gan Kim Yong noted that besides working with overseas partners on research and development, Singapore is taking part in the Covax effort, an international collaboration to ensure equitable access to Covid-19 vaccines around the world.

But he could not share more details on the ongoing discussions with vaccine developers, pharmaceutical companies and research institutions, he said.

"Some of these transactions are strategic in nature, and there is also some business confidentiality involved," he added.