WUHAN, April 17 (Xinhua) -- Over 500 patients with the novel coronavirus disease (COVID-19) have been treated by the plasma of recovered cases so far in Wuhan, local authorities said Friday.

The Wuhan Blood Center has collected nearly 380,000 ml of plasma from 1,101 recovered patients for treating COVID-19 patients, according to Wang Lan, head of the center.

The plasma was sent to 13 designated hospitals, Wang said.

Across Hubei Province, plasma from 1,627 recovered patients was collected to treat over 600 patients, according to Yu Xuehua, with the provincial health commission.

Convalescent plasma processed from the plasma collected from recovered COVID-19 patients contains a large number of protective antibodies.

The first dose of convalescent plasma from a COVID-19 patient was collected on Feb. 1 and the first severely ill patient received the treatment at a hospital in Wuhan on Feb. 9.