Photo: Li Xuanmin/GT

Chinese medical experts on Monday urged all countries to find their Patient Zeros of the novel coronavirus disease (COVID-19), which is a challenging but very necessary task.

There are many clues that can be used to track down Patient Zero, but many people already have positive antibodies in their bodies, making it difficult to identify an infection event, said Liu Peipei, an expert with the Chinese Center for Disease Control and Prevention (CDC), at a media briefing held by the State Council Information Office on Monday in Beijing.

It is also possible that Patient Zero is an asymptomatic patient, leaving no record to check, Liu said.

China needs to find its Patient Zero, but other countries also need to find Patient Zeros in their countries, Liu said, noting that countries should cooperate in this task, as a huge amount of work involving multidisciplinary intersection will be needed, said Jin Qi, head of the Chinese Academy of Medical Sciences' Institute of Pathogen Biology, at the media briefing.

In response to allegations claiming the novel coronavirus is man-made and leaked from a Chinese laboratory, Liu said it is a consensus in the international scientific field that the possibility the novel coronavirus is artificial is very low.

Wang Guiqiang, Director of the Infectious Disease Department at Peking University First Hospital, said at the media briefing that the Chinese government is supporting COVID-19 vaccine research and development in five different technological roadmaps, including adenovirus vaccine, inactivated vaccine, and nucleic acid vaccine, and they are all advancing in an orderly manner with three of them entering phase-two clinical trials.

Plasma therapy has proven effective in clinical treatment, and China has collected plasma from over 10,000 recovered patients and effectively carried out this treatment on 600 to 700 patients. Stem cell treatment is also effective and has cured over 200 critical patients in Wuhan, Chinese medical experts revealed at the briefing.

Before a vaccine is developed, the most effective measure to prevent and control COVID-19 is wearing face masks, Wang noted.

"We cannot rule out the possibility that COVID-19 may stay with human beings for a long time because the contagious respiratory virus involves asymptomatic patients, which is different from the symptoms of SARS," Wang said.

There are two types of asymptomatic COVID-19 infected groups: the first of which sees a longer incubation period and is not really an asymptomatic patient, but has stronger infectivity, while the other is an actual asymptomatic infection, the experts said.

It is unlikely that a sharp reduction in confirmed cases will be seen in the summer, and the pandemic outbreak could occur again in autumn and winter in crowded areas, Wang asserted.

Liu Xuanzun also contributed to this story