Secretary for Food and Health Chan Siu-chee welcomes virus testing professionals from the Chinese mainland in Hong Kong, south China, Aug. 2, 2020. Seven virus testing professionals from the Chinese mainland arrived in Hong Kong on Sunday afternoon as the first batch of mainland supportive teams to help contain a worsening spread of COVID-19 in Hong Kong, south China, Aug. 2, 2020. (Photo/China News Service)

Seven virus testing professionals from the Chinese mainland arrived in Hong Kong on Sunday afternoon as the first batch of mainland supportive teams to help contain a worsening spread of COVID-19 in Hong Kong, south China, Aug. 2, 2020. (Photo/China News Service)

Seven virus testing professionals from the Chinese mainland arrived in Hong Kong on Sunday afternoon as the first batch of mainland supportive teams to help contain a worsening spread of COVID-19 in Hong Kong, south China, Aug. 2, 2020. (Photo/China News Service)

Seven virus testing professionals from the Chinese mainland arrived in Hong Kong on Sunday afternoon as the first batch of mainland supportive teams to help contain a worsening spread of COVID-19 in Hong Kong, south China, Aug. 2, 2020. (Photo/China News Service)