BANGKOK (REUTERS) - Thailand reported on Saturday (July 31) a daily record of 18,912 new coronavirus infections, bringing the country's total accumulated cases to 597,287.

The country also reported 178 new deaths, also a daily record, taking total fatalities to 4,857.

Meanwhile, Thailand will order an additional 10 million doses of the Pfizer/BioNTech Covid-19 vaccine, its health ministry said on Friday, as the Southeast Asian country battles its biggest Covid-19 outbreak to date.

Since April, Thailand has been tackling a surge in infections driven by the highly contagious Delta variant of the coronavirus, pushing hospitals in the capital Bangkok to the brink.

Thailand will take delivery of 20 million doses of the Pfizer Covid-19 vaccine later this year, but also has plans to order an additional 10 million shots from the company, health ministry official Kiatiphum Wongrajit told reporters.

Thailand's vaccine drive has so far depended on Sinovac and AstraZeneca vaccines and faced delays since it began last month. Just 5.6 per cent of the country's 66 million population been fully vaccinated so far.

Thailand manufacturers the AstraZeneca vaccine under licence locally, but production has been much smaller than government expectations, contributing to a delay in its rollout.

The country has received a donation of one million doses of the Sinovac vaccine from China and one million doses of the AstraZeneca vaccine from Japan. Britain has also pledged 415,000 AstraZeneca shots.

Thailand received its first batch of 1.5 million doses of the Pfizer vaccine donated by the US government on Friday.