Virologist Yong Poovorawan says that people can contract COVID-19 after recovering from it and they should be vaccinated.
In his Facebook, Dr Poovorawan was responding to a question on whether a recovered COVID-19 patient should receive the vaccine.
The head of the Centre of Excellence in Clinical Virology at Chulalongkorn University, Dr Poovorawan said inoculation is needed to prevent a repeat of the infection in recovered patients.
Citing a study in Nature Medicine, Dr Poovorawan said the vaccine should be administered three months after the initial infection. The immunity in recovered patients will decline after six months.
The centre was conducting a study where COVID-19 sufferers who have been cured of the virus in the past 3-6 months are given a booster shot.
Those who have recovered for between six months to a year are provided with a two-dose vaccine.
The centre was also running a detailed check of the level of immunity in study subjects and other epidemiological data related to the research.
He said recovered patients in the current outbreak should get vaccinated and book their appointments.
Meanwhile, vaccination campaigns are underway in major provinces with offers of prizes to motivate people to have the jabs.
In Phon district of Khon Kaen, those who have had the shots are eligible for a draw for gold necklaces.
Kittichote Triamvutthikrai, the municipality mayor, said many people are enthusiastic about the vaccination programme and wanted to be part of it. Many locals will be inoculated with the AstaZeneca vaccine starting in July.
The auditorium of the Phon district office will serve as the venue.
People are being encouraged to register for vaccination, Mr Triamvutthikrai said, adding he believed at least 80% of locals will join the inoculation drive.