The general population in China may start getting access to locally manufactured Covid-19 vaccines from November or December, according to a top scientist from the Chinese Centre for Disease Control and Prevention (CDC).During a programme telecast by state broadcaster CCTV this week, Wu Guizhen, the CDC's chief biosafety expert said that preparations are underway for some vaccines to go into mass production.The top scientists also talked about the smooth progress of several vaccine candidates that are in clinical trials, the South China Morning Post reported on Tuesday."I joined the experimental group and had a coronavirus shot in April," Wu said in the programme."I've felt quite good in the past few months, nothing abnormal. The process of inoculation did not cause any localised pain."At least five vaccine candidates developed by China have reached the crucial phase-3 stage, while Russia last month approved a Covid-19 vaccine before the completion of Phase-3 trials.Wu said that she was hopeful about the efficacy and safety of the vaccine candidates developed by China."We expect them to remain effective for one to three years a (but) the results will need to be observed for a longer time," she said.China's military received approval for using a Covid-19 vaccine jointly developed by its research unit and CanSino Biologics Inc. in June itself.The approval for the Recombinant Novel Coronavirus Vaccine (Ad5-nCoV) was granted by the Health Bureau of the Logistics Support Department of China's Central Military Commission on June 25, for one year.