A recovered coronavirus patient from Huanan seafood market donates plasma at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

Recovered coronavirus patient Cai Taoying, who is also a nurse from Hankou Hospital, donates plasma at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

A recovered coronavirus patient (2nd L) from Huanan seafood market holds a certificate for blood donation while donating plasma at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

Donated plasma of a recovered coronavirus patient is seen at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

A recovered coronavirus patient from Huanan seafood market donates plasma at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

Recovered coronavirus patient Cai Taoying, who is also a nurse from Hankou Hospital, donates plasma at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

A medical staff measures blood pressure of a plasma donor, who is a recovered coronavirus patient, at Wuhan Blood Center in Wuhan, capital of central China's Hubei Province, Feb. 17, 2020. Cured patients who were infected with COVID-19 are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Cai Yang)

A cured coronavirus patient cheers for other patients before donating plasma at Chongqing Blood Center in southwest China's Chongqing Municipality, Feb. 17, 2020. Cured patients who were infected with the novel coronavirus disease (COVID-19) are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Tang Yi)

A cured coronavirus patient donates plasma at Chongqing Blood Center in southwest China's Chongqing Municipality, Feb. 17, 2020. Cured patients who were infected with the novel coronavirus disease (COVID-19) are called upon to donate plasma as initial results had indicated the effectiveness of convalescent plasma-derived therapeutic products in curing infected patients in severe and critical conditions. Some recovered patients regard the donation as a way to pay back to the society after they received timely and effective treatment. (Xinhua/Tang Yi)