Factbox : When and which COVID-19 vaccines are likely to be available in Asia

Here are details of estimated distribution timelines, announced supply deals and clinical trials in the region.

On Dec. 30, the city-state became the first Asian country to begin inoculation of the Pfizer vaccine, despite one of the lowest fatality rates from the coronavirus worldwide.

It has signed advanced purchase pacts and made early down-payments on vaccines from Pfizer, Moderna and China's Sinovac Biotech Ltd.

It expects to have secured enough vaccines for its 5.7 million people by the third quarter of 2021.

The country has secured about 140 million doses: 53.8 million from AstraZeneca, 51 million from Novavax Inc, 10 million from Pfizer, and 25.5 million from distribution programme COVAX.

It expects delivery of 3.8 million doses of AstraZeneca's vaccine in January and February 2021, and plans to begin inoculations in February.

Novavax agreed to supply 10.7 million doses, with initial doses to be delivered by mid-2021.

China has not announced supply deals with Western drugmakers, which have partnered with private firms in the country instead.

AstraZeneca's vaccine may be approved in China by mid-2021 and is being produced by its Chinese partner Shenzhen Kangtai Biological Products Co Ltd.

Additionally, Shanghai Fosun Pharmaceutical Group Co Ltd plans to buy at least 100 million doses of the Pfizer/BioNTech vaccine.

Tibet Rhodiola Pharmaceutical Holding Co is bringing in Russian vaccine candidate Sputnik V and plans early and mid-stage trials in China.

On Dec. 31, China gave its first COVID-19 vaccine approval to a shot developed by a unit of state-backed Sinopharm, for use by the general public.

Prior to the approval, China had already vaccinated more than 2 million people under an emergency use programme, using three different shots developed by Sinopharm units and Sinovac.

Japan has deals to buy 120 million doses from Pfizer/BioNTech in the first half of 2021 and to purchase 120 million from AstraZeneca - the first 30 million to be shipped by March 2021. It has also agreed to buy 250 million from Novavax.

Japan is also in talks with Johnson & Johnson, and has a deal with Shionogi & Co Ltd.

Experts said vaccine makers would need to run at least Phase I and II trials in Japan before seeking approval for use.

The country has deals to buy 20 million doses each from AstraZeneca and Pfizer, 40 million from Moderna and 4 million doses from Johnson & Johnson's Janssen.

It will procure additional doses for 10 million people through COVAX, and its total supply deals will be enough to cover up to 56 million people.

Inoculation will begin in late February with the AstraZeneca vaccine.

In January, India approved two COVID-19 vaccines for emergency use, one developed by AstraZeneca, and the other backed by a state-run institute.

It plans to roll out a vaccination programme by next week, aiming to cover 300 million people by July.

Taiwan has agreed to buy almost 20 million doses of COVID-19 vaccine, including 10 million from AstraZeneca. It plans to get a total of 30 million vaccine doses to cover about 65% of its population.

The first vaccines are expected to arrive in March.

Thailand has secured 63 million doses of COVID-19 vaccine -- 61 million from AstraZeneca and 2 million from Sinovac.

The country will receive its first delivery of the AstraZeneca vaccine ahead of schedule before the second quarter, the government said.

The Southeast Asian nation has agreed to buy 12.8 million doses of the Pfizer vaccine and is in talks with the firm and others including Moderna, J&J, Sinovac and Russia's Gamaleya Institute to secure more to cover 83% of its population.

Pfizer will deliver the first batch of 1 million doses in the first quarter of 2021.

The archipelago has signed only one supply deal, with the help of the private sector, to acquire 2.6 million doses of the AstraZeneca vaccine.

It is in talks with seven vaccine makers -- Novavax, Moderna, AstraZeneca, Pfizer, Sinovac, Johnson & Johnson and Russia's Gamaleya Institute-- to procure at least 148 million doses to inoculate close to two thirds of its population this year.

Southeast Asia's most populous nation has secured 125.5 million doses from Sinovac, 30 million from Novavax and is in talks with AstraZeneca and Pfizer to buy 50 million doses each. It also expects to get 16 million from COVAX.

Indonesia is testing Sinovac's vaccine and preparing to start mass vaccination of medical staff and other frontline workers on Jan. 13.

Vietnam has a deal to buy 30 million doses from AstraZeneca and in talks to purchase vaccines from Pfizer, Russia and China.

Bangladesh signed a deal with India's Serum Institute to buy 30 million doses of the AstraZeneca vaccine.