Infusions of antibody-rich blood plasma from people who have recovered from the coronavirus have proven effective in treating severely ill patients, Egypt's health minister said on Friday.

Hala Zayed said in a statement that recent trials had shown promising results in increasing the recovery rate of critically ill patients and lessening the need for ventilators.

She also called on those who recovered from the highly-contagious virus to head to the nearest ministry-affiliated blood transfusion center to donate plasma, 14 days after they recover.

The statement didn't provide further details on the number of recoveries from that treatment, but the ministry said last week that 30 patients had recovered after being injected with plasma extracted from the blood of recovered patients.

Egypt has so far registered 31,115 coronavirus cases, 8,158 recoveries and 1,166 deaths.

The country introduced the plasma treatment trials for the first time on 30 April, just days after the US Food and Drug Administration said convalescent plasma had the potential to lessen the severity or shorten the length of illness caused by COVID-19.

According to the FDA, the plasma treatment is used only for severe and critical cases. 

Plasma extracted from one recovered patient could be infused into two seriously ill patients, the health ministry spokesman has said.

Recovered patients can make their blood donations at five blood transfusion centers in five Egyptian cities: Giza, Alexandria, Minya, Luxor and Tanta.

Egypt's updated treatment protocol for coronavirus cases relies on some antiviral drugs and vitamins, according to a document released by the health ministry earlier this week.