After the fifth phase of easing of COVID-19 restrictions started on Wednesday, authorities at the centre anticipate that Thais will return in large numbers to their home provinces during the Asarnha Bucha and the Buddhist Lent Day period after the government earlier put on hold three Songkran holidays this year at the height of the outbreak to prevent people from travelling and spreading the disease.
However, the Cabinet on Tuesday approved July 27 as a substitute Songkran holiday, though it has yet to assign the remaining two Songkran holidays.
"When they return home, they will gather with friends for drinking. It is their way of life," Dr Taweesin said.
He said it has been fortunate that disease monitoring and tracing in local areas is efficient with village health volunteers working to prevent the spread of the disease from returnees to elderly members of their families.
However, evidence had emerged that illegal migrant workers have continued to sneak across borders and mingle with local residents, Dr Taweesin said.
"So we cannot feel 100% at ease. It was reported last month that more than 2,900 illegal workers crossed the border and stayed with us," he said.
He said that after the fifth-stage relaxation, Thais must continue to comply with health safety measures to protect themselves from the disease by maintaining physical distancing and wearing face masks.
"Thailand has survived the past six months because of cooperation from everyone," Dr Taweesin said.
"From the start, we might have felt uncomfortable. But now we believe Thais maintain a sense of responsibility."
Prime Minister Prayut Chan-o-cha, chairman of the CCSA, said on Thursday (July 2) that all went well on the first day of the relaxation on Wednesday, without any local transmissions reported.
However, he said he has instructed officials to step up inspections of premises which were allowed to reopen in the latest stage of loosening of restrictions, and prepare measures to prevent any further transmission.
Among premises allowed to reopen from Wednesday were pubs and bars, karaoke bars, and bath-sauna-massage establishments.
Asked by reporters about the long holiday, Gen Prayut said revellers should avoid crowds as part of disease control measures.
However, the prime minister said people are expected to travel more after the fifth-stage easing of the lockdown, which will give a much-needed boost to the local economy.
Udom Kachintorn, a former deputy education minister, said the public should continue to wear face masks and observe social-distancing measures.