Prime Minister Prayut Chan-o-cha has vowed to reopen the country to fully vaccinated tourists from Nov 1.

However, some medical experts have raised concerns over public health safety.

Gen Prayut announced the government's reopening plan in a special televised speech Monday night, saying the country will admit fully vaccinated tourists from low-risk countries and that they will not have to spend time in Covid-19 quarantine.

The Tourism Authority of Thailand (TAT) has been preparing for the country's reopening and has already implemented pilot programmes in key tourist destinations such as Phuket, said Tourism and Sports Minister Phiphat Ratchakitprakarn on Tuesday.

TAT is now specifying which countries should be included in the list of low Covid-19 risk nations, he said. "More details of the reopening plan are expected to be discussed at the next meeting of the Centre for Covid-19 Situation Administration (CCSA) tomorrow," Mr Phiphat said.

At this point, four to five countries have been named including Britain, Germany, the US and China, he said.

But Dr Thira Woratanarat, an associate professor at Chulalongkorn University's Faculty of Medicine, has cautioned that the number of daily new Covid-19 infections may surge by at least twice the current figures after reopening.

Citing an analysis of infections experienced by Chile, which reopened on Oct 1, and Denmark, reopened since early September, Dr Thira said the number of new Covid-19 cases may jump to around 20,000 per day and then keep doubling every three weeks after that.

Prof Dr Thiravat Hemachudha, the Thai Red Cross Emerging Infectious Diseases Health Science Centre chief, said he personally supports the reopening as long as it won't exacerbate the Covid-19 situation in the country.

Nonetheless, he said he is concerned that the arrival of international tourists could trigger another major outbreak.

Virologist Anan Jongkaewwattana, from the National Centre for Genetic Engineering and Biotechnology, made similarly apprehensive comments about the reopening on his Facebook page.

"If 100,000 tourists visit, how will we do RT-PCR tests because we have never done so many before?" he asked.