WASHINGTON - A clinical trial has begun in the United States to evaluate whether anti-malaria drug hydroxychloroquine, given together with antibiotic azithromycin, can prevent COVID-19 hospitalization and death, according to a release published by the US National Institutes of Health (NIH) on Thursday.

Hydroxychloroquine is approved by US Food and Drug Administration (FDA) to prevent and treat malaria, as well as to treat the autoimmune diseases rheumatoid arthritis and lupus. And azithromycin is FDA-approved antibiotic.

The trial will enroll approximately 2,000 adults across the United States, who are infected with SARS-CoV-2, the novel coronavirus that causes COVID-19, and exhibiting symptoms of fever, cough or shortness of breath, according to the release.

The investigators anticipate that many participants will be 60 years of age or over, or have a comorbidity associated with developing serious complications from COVID-19, such as cardiovascular disease or diabetes, NIH said.

Participants will be randomly assigned to receive short-term treatment at home with either hydroxychloroquine and azithromycin or matching placebos, it said.

Those assigned to the experimental treatment group will take 400 milligrams of hydroxychloroquine twice on the first day, and 200 mg twice daily for an additional six days. They will also take 500 mg of azithromycin on the first day, and 250 mg daily for an additional four days.

The control group will receive equivalent numbers of placebo pills, and neither the participants nor the study team will know who received experimental treatment or placebo until the end of the trial, according to the NIH.

Participants will record their symptoms, adherence to treatment, and major events such as hospitalizations in a diary for 20 days.

The first participant has enrolled on Thursday in San Diego, California. And Teva Pharmaceuticals is donating medications for the study, according to the NIH.

Currently, there is no specific therapeutics approved by the FDA to treat people with COVID-19.

Many clinical trials are planned or underway to evaluate the safety and effectiveness of hydroxychloroquine for treatment of adults hospitalized with COVID-19, and some preliminary reports have suggested that hydroxychloroquine, alone or in combination with azithromycin, may benefit people with COVID-19, according to the NIH.

The NIH said that the main objective of the study is to determine whether hydroxychloroquine and azithromycin can prevent hospitalization and death due to COVID-19. Additionally, investigators will evaluate the safety and tolerability of the experimental treatment for people with SARS-CoV-2 infection.

The FDA issued an Emergency Use Authorization on March 28 to allow hydroxychloroquine and medical-grade chloroquine to be distributed from the Strategic National Stockpile and prescribed by doctors, to hospitalized adolescents and adults with COVID-19, when a clinical trial is not available or feasible.