"Plasma therapy is effective and safe," said Zhong Nanshan, a renowned Chinese respiratory expert, at a press conference in Guangdong Province on Tuesday. 

Zhong was responding to a question about the effectiveness and risk of using plasma from recovered coronavirus pneumonia patients to treat patients with severe symptoms. 

In explaining his position, Zhong recalled that plasma therapy was first used to treat H5N1 in 2005 and again to treat H1N1 in 2009 with positive results. 

Antibodies have been found in the plasma of some recovered COVID-19 patients, meaning they can fight the coronavirus in a better way. Many patients in Wuhan have donated their blood for this treatment.

Ten coronavirus patients in Wuhan have received the treatment so far, six of whom have shown signs of their symptoms easing. 

Zhong said Guangdong Province is considering using the same treatment. Guangdong currently has the second-highest number of confirmed COVID-19 patients as of February 18, next only to Hubei Province, with Wuhan as its capital.

"The advantage of the therapy is that it doesn't conflict with different blood types," Zhong said, expressing optimism about the treatment.

He, however, stressed that it's particularly effective to severely ill patients, but not for critically ill patients.

Person-to-person transmission still an issue

Zhong also said person-to-person transmission of the novel coronavirus is still happening in Wuhan, the epicenter of the epidemic.

The respiratory expert said it is critical that Wuhan differentiate between healthy people and those who have contracted the novel coronavirus and distinguish its infection from the common flu.

"It's urgent to differentiate between those two issues, or person-to-person (transmission) won't stop in Wuhan," Zhong asserted, adding that what Wuhan has achieved plays a vital role in the national fight against the epidemic.

Zhong told reporters work and research are speeding up on medicines to treat this new virus and a drug called Chloroquine phosphate has shown good clinical efficacy.

"Chloroquine is not really a kind of medicine with a special effect, but it is worthy of study," Zhong said.

(CGTN's He Weiwei and Chen Yilin also contributed to the story.)