Covid-19 is becoming a seasonal virus in Thailand, primarily active during two periods of the year, experts said.
Yong Poovorawan of the Faculty of Medicine, Chulalongkorn University said on his Facebook page that infections are expected to peak between June and September and November and February.
He said the virus can re-infect a person but is unlike diseases such as measles which, once infected or vaccinated, can build immunity that lasts for life.
Dr Yong said herd immunity cannot end the spread of Covid-19. Though many people have become immune to contracting the virus, the pandemic continues.
He said vaccines will not stop the pandemic.
From Dec 4-10, there were 3,961 new infections, said the Department of Disease Control. Some 107 deaths were reported nationwide during the period. There have been 2,492,054 infections nationwide this year so far.