KUALA LUMPUR:Malaysia said on Wednesday it was talking with Pfizer and other companies to secure more COVID-19 vaccine doses to cover 83% of its population, and is drawing up plans to arrange ultra-cold storage in its tropical heat.

The Southeast Asian nation says it has so far got enough doses to inoculate 40% of its 32 million people, and has promised to spend $500 million to buy enough vaccines.

The government, which has struck a deal to buy 12.8 million doses of U.S. drugmaker Pfizer-BioNTech's shot, said it was in talks for an option to buy more doses to cover another fifth of the population.

It is also in final talks to secure a total of 23.9 million doses from Chinese manufacturers Sinovac Biotech Ltd and CanSino Biologics, and from Russia's Gamaleya Institute, the maker of the Sputnik V vaccine, Science Minister Khairy Jamaluddin said.

It will secure additional AstraZeneca vaccines under the global COVAX facility, and has begun talks with Moderna and Johnson & Johnson as a buffer, the minister added.

Malaysia, where temperatures average 30 degrees Celsius year-round, wants to ensure a distribution network that does not need to store vaccines for long, Khairy said.

"Once the Pfizer vaccines come in, we are hoping that it will be a just-in-time roll out of vaccination," he said.

Pfizer's vaccines need to be stored and transported at minus 70 degrees Celsius (-94F), although they can be kept in a fridge for up to five days, or up to 15 days in a thermal shipping box.

Some Asian countries have expressed reservations about the Pfizer vaccine due to tropical heat, remote island communities and a lack of ultra-cold freezers.

Malaysian's vaccine supply committee will identify ultra-cold storage facilities and aims to stagger distribution to ensure coverage in remote regions, ahead of the arrival of Pfizer's first shipment in February, Khairy said.

Neighbouring Singapore was the first Asian nation to take delivery of a batch of the Pfizer vaccine on Monday from Belgium.