Coronavirus vaccines being developed in China may be ready for use by the general public as early as November, an official with the Chinese Center for Disease Control and Prevention said. Phase 3 clinical trials were proceeding smoothly and the vaccines could be ready for the general public in November or December, CDC Chief Biosafety Expert Wu Guizhen told state TV. Wu, who said she has experienced no abnormal symptoms in recent months after taking an experimental vaccine herself in April, did not specify which vaccines she was referring to, the Shanghai Daily reports. China has four Covid-19 vaccines in the final stage of clinical trials. At least three of those have already been offered to essential workers under an emergency-use program launched in July.

A unit of China National Pharmaceutical Group (Sinopharm) and U.S.-listed Sinovac Biotech are developing the three vaccines under the state’s emergency use program. Representatives of the firms said that they hope their vaccines will be approved after phase 3 trials as early as the end of the year. A Sinovac Spokesman said that 90% of its employees and their families – between 2,000 and 3,000 people – had voluntarily taken its vaccine. A fourth Covid-19 vaccine developed by CanSino Biologics was approved for use by the Chinese military in June. There are currently nine vaccine candidates in late-stage human trials. None of the people who have received candidate Covid-19 vaccines developed by China for emergency use have exhibited serious side effects or contracted the coronavirus.

China has established a national coronavirus center to collect virus samples, perform genome sequencing, train medical personnel, conduct Covid-19-related international cooperation, and develop national standards, Gao Fu, Director of the Chinese Center for Disease Control and Prevention, said. The world is still in the early stages of the pandemic, Gao said at the Beijing 2020 Zhongguancun Forum, which included China’s most senior epidemic experts. Shi Zhengli, Director of the Wuhan Institute of Virology, said that the intermediate host and transmission path of the virus from nature to humans remain unknown, and may never be known, which makes Covid-19 almost untraceable.

Although China reported zero domestically-transmitted cases in the Chinese mainland in a month, and China’s experiences have proven successful, observers remain concerned about uncertainties, which come from limited knowledge about the virus, which is still spreading around the world, and also the risk of imported infections. Zhong Nanshan, China’s renowned respiratory disease expert, said that the Covid-19 pandemic will very likely continue to spread in winter and spring. If another domestic outbreak emerges, China will continue to take joint prevention and control measures at the community level, wide-ranging nucleic acid screening, tracing close contacts and isolating asymptomatic patients with positive nucleic acid results, the Global Times reports.