China's leading respiratory expert urged people to continue wearing face masks as the winter flu season approaches.

Wearing face masks is still an effective way to prevent both COVID-19 and common flu, said Zhong Nanshan, a renowned expert on respiratory disease prevention.

Addressing the China Health Science and Technology Innovation Development Conference in Shenzhen on Friday, he said there have been at least four cases of people catching both the influenza virus and novel coronavirus.

Zhong, also an academician of the Chinese Academy of Engineering, underscored the vital role of fast and timely virus testing in identifying whether a patient is infected with the flu virus or novel coronavirus.

He said current statistics showed that the flu infection rate in China has dropped dramatically this year because people were wearing face masks.

Clinical research showed that Remdesivir could help shorten patients' recovery period, but its effects on severe patients are not obvious, he said.

In terms of another medicine, Chloroquine, which has caused debate and divided opinions among medical specialists treating COVID-19, Zhong said it has some effects on patients who take 500 milligrams twice a day.

He made the comment based on clinical experiences of doctors at Sun Yat-sen Memorial Hospital, Sun Yatsen University, in Guangzhou, Guangdong province.

Zhong also said the blood plasma of patients who are in the process of recovery, and some traditional Chinese medicines, have proven to have certain effects in COVID-19 treatment. Clinical observations showed that Lianhua Qingwen, a commonly available OTC medicine in China, could help alleviate COVID-19 symptoms.

Zhong also said of all the vaccines that are still in the process of clinical experiments, China's vaccines are making steady progress and not falling behind.

Effectiveness, he stressed, is only one of the many factors to determine whether a vaccine is a good one.

Other factors, such as whether the vaccine is convenient for production, whether it has side-effects, how long the antibody could last and the cost of transportation and restoration, all matter in the judgement.

Previous experience showed that it usually takes five to six years to find a "good vaccine" that could be widely used. Now it might take two or three years to find a good COVID-19 vaccine, Zhong said.