Miguel Ángel Benítez was hospitalized at the Virgen del Rocio Hospital in Seville, where he received lopinavir-ritonavir, an antiretroviral drug sold under the brand name Kaletra, according to Metro UK, which cited El Pais.

The drug — which has been used to treat HIV and AIDS for over 10 years — was combined with interferon beta, a protein that prevents cells from becoming infected and is used on people with multiple sclerosis patients, the news outlet reported.

Santiago Moreno, head of infectious diseases at the Ramón y Cajal hospital in Madrid, said the “SARS-CoV-2 protease is very similar to that of HIV,” using another name for the novel coronavirus.

“This enzyme is essential for the virus to replicate. The combination of lopinavir and ritonavir inhibits and blocks HIV,” he said, according to Metro.

Spanish Health Minister confirms the listeriosis outbreak began in the larded meat plant, Seville, Spain – 22 Aug 2019

“The results that we have so far regarding its use against coronaviruses are encouraging.”

Researchers in Spain cautioned that not all coronavirus patients would necessarily respond to the treatment the way Benítez did.

But a research professor at Imperial College London said that if the widely available HIV drugs prove to be successful against COVID-19 on a large scale, they could quickly be administered to the coronavirus patients.

“There is some evidence from laboratory studies that some HIV drugs might also be active against SARS-CoV-2 and a trial has been underway for a while using these drugs against MERS,” Professor Graham Cooke told Metro, referring to Middle East Respiratory Syndrome.