Dr Manoon Leechawengwongs cited studies published on medRxiv revealing that dengue antibodies may boost immunity against Covid-19.
He said Thailand has more than 100,000 dengue patients every year, and many Thais take the BCG vaccine for tuberculosis to avoid dengue infections.
This, he said, may explain why there are far fewer Covid-19 cases here than in other countries.
However, Manoon said, people still need to follow preventive measures, including wearing face masks, washing hands and maintaining social distancing to prevent a second wave of infections.