Chinese Ambassador to Liberia Zhang Yue said medical supplies and equipment sent directly to the capital, Monrovia, from China were flown in by a special cargo plane on Monday afternoon. The delivery includes personal protection equipment, medical instruments, sanitizers, disinfectants, symptom relief medicines and non-contact infrared thermometers.

China has launched an emergency mechanism with simplified procedures and sent a special cargo plane for quick delivery of the supplies, Zhang said.

President Ellen Johnson-Sirleaf of Liberia lauded the Chinese government for the help.

Stepping up research

On Tuesday, the WHO said that two experimental vaccines for Ebola were set to start clinical trials in the coming weeks and there could be enough early-stage data to plan for their emergency use later this year.

WHO Assistant Director-General Marie-Paule Kieny said: "There is a way to fast-track vaccine clinical trials."

Meanwhile, Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, said in an article in the New England Journal of Medicine that "production scale-up" of ZMapp was under way but would take time.

ZMapp is a mix of antibodies, produced by Mapp Biopharmaceutical of San Diego, US, which was given to two US medics infected with Ebola and evacuated to Atlanta for treatment.

In China, testing capacity is ready for Ebola, said Dong of the China's CDC.

Among all tools available for the virus screening, the nucleic acid testing takes only several hours, he added.

But research on Ebola treatment and vaccine "remained at the fledging stage in China", he conceded.

To enhance capacity, an advanced lab of the highest bio-safety level 4 is being built in Wuhan, capital of Hubei province, and is expected to open in 2016, he said.

Biocontainment precautions are required to isolate dangerous biological agents in an enclosed facility. The levels of containment range from the lowest bio-safety level 1 to the highest at level 4, according to the US CDC, which defines the levels.

"For the moment, our public health teams won't be able to bring back any Ebola samples for research," Li Qun said.