US researchers, following the lead of scientists in other countries, have launched studies to see whether widely-available, low-cost generic drugs can be used to help treat the illness caused by the new coronavirus.

There are currently no vaccines or treatments for the highly-contagious Covid-19 respiratory illness, so patients can only receive supportive care for now.

But a 1,500-person trial, led by the University of Minnesota, began this week to see whether malaria treatment hydroxychloroquine can prevent or reduce the severity of Covid-19. Two other trials are studying the blood pressure drug losartan as a possible treatment for the disease.

The malaria drug, also being tested in China, Australia and France, was touted earlier this week by Tesla Chief Executive Elon Musk, who recovered from malaria in 2000 after taking the medication.

Besides having a direct antiviral effect, hydroxychloroquine suppresses the production and release of proteins involved in the inflammatory complications of several viral diseases.

“We are trying to leverage the science to see if we can do something in addition to minimising contacts,” said Dr Jakub Tolar, dean of the University of Minnesota Medical School and vice president for clinical affairs. “Results are likely in weeks, not months.”

Most people infected with the new coronavirus develop only mild flu-like symptoms, but around 20 per cent can have more severe disease that can lead to pneumonia requiring hospitalisation.

The fast-spreading virus, which emerged in China in December and is now in more than 150 countries, has infected more than 214,000 and killed over 8,700 people worldwide, including at least 145 in the United States. Experts say it could take a year or more to have a preventive vaccine ready, so effective treatments are desperately needed.

Before and after photos show impact of coronavirus around the world Show all 20 1 /20 Before and after photos show impact of coronavirus around the world Before and after photos show impact of coronavirus around the world Top: Nabi Younes market, Mosul Bottom: Charles Bridge, Prague Reuters Before and after photos show impact of coronavirus around the world Grand Mosque, Mecca A combination photo shows Muslim pilgrims wearing protective face masks, following the outbreak of the coronavirus, as they pray at Kaaba in the Grand Mosque in the holy city of Mecca, Saudi Arabia March 3, 2020 (top) and general view of Kaaba at the Grand Mosque which is almost empty of worshippers, after Saudi authority suspended umrah (Islamic pilgrimage to Mecca) amid the fear of coronavirus outbreak, at Muslim holy city of Mecca, Saudi Arabia March 6, 2020. REUTERS/Ganoo Essa TPX IMAGES OF THE DAY GANOO ESSA Reuters Before and after photos show impact of coronavirus around the world Sagrada Familia, Barcelona A combination photo shows tourists gathering around Sagrada Familia basilica, before closing it and suspending its construction work as a precautionary measure due to the coronavirus outbreak in Barcelona, Spain March 11, 2020. Picture taken March 11, 2020 and an empty street of tourists as basilica stopped receiving visitors and suspend its construction work as a precautionary measure due to the coronavirus outbreak, in Barcelona, Spain March 13, 2020. REUTERS/Nacho Doce NACHO DOCE Reuters Before and after photos show impact of coronavirus around the world Nabi Younes market, Mosul A combination picture shows people shopping at the Nabi Younes market (top) March 11, 2020 and the empty market during a curfew imposed by Iraqi authorities, following the outbreak of coronavirus, in east Mosul, Iraq March 15, 2020. REUTERS/Abdullah Rashid ABDULLAH RASHID Reuters Before and after photos show impact of coronavirus around the world Basra Grand Mosque, Iraq A combination picture shows worshipers walking out after performing prayers at Basra Grand Mosque in Basra, Iraq March 12, 2020 and the mosque seen empty after a curfew was imposed to prevent the spread of coronavirus, March 17, 2020. REUTERS/Essam Al-Sudani ESSAM AL-SUDANI Reuters Before and after photos show impact of coronavirus around the world Charles Bridge, Prague A combination picture shows tourists walking across the medieval Charles Bridge in Prague, Czech Republic, November 7, 2019 and the bridge empty as the Czech government restricts movement of people to slow the spread of the new coronavirus disease (COVID-19), Czech Republic, March 16, 2020. REUTERS/David W Cerny DAVID W CERNY Reuters Before and after photos show impact of coronavirus around the world Taj Mahal hotel, India A combination picture shows the Taj Mahal hotel, November 25, 2018 and after the government tightened up measures for coronavirus prevention in Mumbai, India March 17, 2020. REUTERS/Francis Mascarenhas FRANCIS MASCARENHAS Reuters Before and after photos show impact of coronavirus around the world Dubai Mall, UAE A combination picture shows people at Dubai Mall (top), following the outbreak of coronavirus, in Dubai, United Arab Emirates, March 12, 2020 and the mall seen almost empty of customers, as precaution amid the outbreak of coronavirus, March 16, 2020. REUTERS/Satish Kumar SATISH KUMAR SUBRAMANI Reuters Before and after photos show impact of coronavirus around the world Beirut March, Lebanon A combination picture shows men gathered at a beach in Beirut March 12, 2020, and the gathering place seen empty after Lebanon declared a medical state of emergency as part of the preventive measures against the spread of the coronavirus, in Beirut, Lebanon March 15, 2020. REUTERS/Mohamed Azakir MOHAMED AZAKIR Reuters Before and after photos show impact of coronavirus around the world Gateway of India, Mumbai A combination picture shows the Gateway of India, August 18, 2016 and after the government tightened up measures for coronavirus prevention in Mumbai, India March 17, 2020. REUTERS/Danish Siddiqui/Francis Mascarenhas FRANCIS MASCARENHAS Reuters Before and after photos show impact of coronavirus around the world Cairo University, Egypt A combination picture shows students attending a lecture at Cairo University (top) in Cairo, Egypt, February 12, 2020 and seats seen empty at the lecture hall following government efforts to slow the spread of the coronavirus, March 15, 2020. REUTERS/Shokry Hussien TPX IMAGES OF THE DAY SHOKRY HUSSIEN Reuters Before and after photos show impact of coronavirus around the world Amman Citadel, Jordan A combination picture shows tourists posing for a picture at Amman Citadel, March 10, 2020, and the citadel seen empty after its closure to prevent the spread of the coronavirus in Jordan, in Amman, Jordan March 15, 2020. REUTERS/Muhammad Hamed MUHAMMAD HAMED Reuters Before and after photos show impact of coronavirus around the world Church of the Nativity, Bethlehem A combination picture shows visitors, wearing masks as a preventive measure against coronavirus, arriving at the Church of the Nativity in Bethlehem in the Israeli-occupied West Bank March 5, 2020, and the same area seen almost empty of people following the closure of the church to prevent the spread of the coronavirus March 6, 2020. REUTERS/Mussa Qawasma MUSSA ISSA QAWASMA Reuters Before and after photos show impact of coronavirus around the world Beirut March, Lebanon A combination picture shows people walking at Beirut's seaside Corniche March 15, 2020, and the corniche seen empty after Lebanon declared a medical state of emergency as part of the preventive measures against the spread of the coronavirus, in Beirut, Lebanon March 15, 2020. REUTERS/Mohamed Azakir MOHAMED AZAKIR Reuters Before and after photos show impact of coronavirus around the world Cairo, Egypt A combination picture shows school children leaving the primary school of Omar El Mokhtar in Cairo, Egypt March 11, 2020 and the school seen closed following government efforts to slow the spread of the coronavirus March 16, 2020. REUTERS/Rania Gomaa RANIA GOMAA Reuters Before and after photos show impact of coronavirus around the world Cairo University, Egypt A combination picture shows school children lining up at start of the day classes in Thamret Al Tawfiq School (top) in Cairo, Egypt March 8, 2020, and the school seen empty following government efforts to slow the spread of the coronavirus, March 15, 2020. REUTERS/Hanaa Habib STRINGER Reuters Before and after photos show impact of coronavirus around the world Victoria Memorial, India A combination picture shows the historic Victoria Memorial monument June 21, 2019 and after the government tightened up measures for coronavirus prevention, in Kolkata, India March 17, 2020. REUTERS/Rupak De Chowdhuri RUPAK DE CHOWDHURI Reuters Before and after photos show impact of coronavirus around the world Amman Citadel, Jordan A combination picture shows tourists visiting the Amman Citadel, March 10, 2020, and the citadel seen empty after its closure to prevent the spread of the coronavirus, in Amman, Jordan March 15, 2020. REUTERS/Muhammad Hamed MUHAMMAD HAMED Reuters Before and after photos show impact of coronavirus around the world Amman Citadel, Jordan A combination picture shows tourists visiting the pillars of the Roman Temple of Hercules at the Amman Citadel, March 10, 2020, and the citadel seen empty after its closure to prevent the spread of the coronavirus, in Amman, Jordan March 15, 2020. REUTERS/Muhammad Hamed MUHAMMAD HAMED Reuters Before and after photos show impact of coronavirus around the world Sidon, Lebanon A combination picture shows people playing cards inside a cafe, March 12, 2020, and the cafe seen closed after Lebanon declared a medical state of emergency as part of the preventive measures against the spread of the coronavirus, in Sidon, Lebanon March 16, 2020. REUTERS/Ali Hashisho ALI HASHISHO Reuters

A French team on Tuesday said initial results from a 24-patient trial of hydroxychloroquine showed that 25 per cent of patients given the drug still carried the coronavirus after six days, compared with 90 per cent of patients given a placebo.

Tolar said he bought 1,500 doses of hydroxychloroquine for a “laughable” amount of money. “We don’t need a multibillion-dollar investment. It is part of the beauty of this approach,” he said.

But he and others cautioned that people should not be using any prescription drugs without medical oversight.

“These treatments should be used only in hospitals by critical care specialists,” said Dr Russel Buhr, critical care pulmonologist at the University of California, Los Angeles.

Also this week, the University of Minnesota launched two trials testing losartan – one to measure whether the hypertension drug reduces the risk of organ failure for Covid-19 patients who have been hospitalised, and another looking at whether the drug can limit the need for hospitalisations.

Results from a remdesivir trial in China could come early next month while Gilead has begun two international trials of the drug that previously failed as a potential Ebola treatment (Reuters) (REUTERS)

Losartan is an angiotensin receptor 1 (AT1R) blocker, which researchers say could play a role in blocking an enzyme used by the virus to bind to cells.

Pharmaceutical companies are also working to develop treatments for Covid-19, including Gilead Sciences Inc’s experimental antiviral drug remdesivir, which is given to hospitalised patients via intravenous infusion over several days.

The New England Journal of Medicine earlier this month described how the drug was successfully used on the first patient infected by the novel coronavirus in the United States.

Results from a remdesivir trial in China could come early next month, while Gilead has begun two international trials of the drug that previously failed as a potential Ebola treatment. And the National Institutes of Health last month began testing it on patients in a US trial.

“We are focusing on high-risk patients,” said Dr Andre Kalil, infectious disease specialist at the University of Nebraska Medical Centre and the U.S. trial’s lead investigator. “Our hope is that remdesivir will show that patients will be improving faster.”

Companies including Regeneron Pharmaceuticals Inc, Eli Lilly and Co and Takeda Pharmaceutical Co have begun to develop coronavirus treatment candidates, but human testing of their drugs has not yet started.

Anti-inflammatory drugs, like Regeneron’s Kevzara and Roche Holding AG’s Actemra, have been used to treat the lung inflammation caused by Covid-19.

But in a disappointment, Chinese investigators reported this week that Kaletra, a combination HIV drug sold by AbbVie , failed to improve outcomes for seriously ill Covid-19 patients.