Reasons for hope: the drugs, tests and tactics that may conquer coronavirus - Reuters

(Reuters) - With much of the world living in lockdown, the spread of the new coronavirus, SARS-CoV-2, that was first detected in China late last year is beginning to slow in some places. As of Friday, 2.18 million people had been infected and 147,000 killed by COVID-19, the disease caused by the virus.

FILE PHOTO: A computer image created by Nexu Science Communication together with Trinity College in Dublin, shows a model structurally representative of a betacoronavirus which is the type of virus linked to COVID-19, better known as the coronavirus linked to the Wuhan outbreak, shared with Reuters on February 18, 2020. NEXU Science Communication/via REUTERS

While a safe, effective vaccine is still more than a year away, researchers are rushing to repurpose existing drugs and non-drug therapies as well as testing promising experimental drugs that were already in clinical trials.

Even moderately effective therapies or combinations could dramatically reduce the crushing demand on hospitals and intensive care units, changing the nature of the risk the new pathogen represents to populations and healthcare systems.

New drugs, together with new diagnostics, antibody tests, patient- and contact-tracing technologies, disease surveillance and other early-warning tools, mean the anticipated next “wave” of the global pandemic does not have to be nearly as bad as the first.

More than 70 vaccine candidates are also in development around the world, with at least five in preliminary testing in people. Below are some of the drugs, vaccines and other therapies in development.

(For a related graphic, open this in a web browser: reut.rs/3bhMUaE)

DRUGS

REMDESIVIR - GILEAD SCIENCES

Antiviral drug, originally developed to combat RNA viruses including respiratory syncytial virus. At least 13 trials underway in China, Europe and the United States with preliminary results from two Chinese trials expected as soon as April 2020. A February assessment by the WHO flagged this candidate as the most promising for battling COVID-19.

CAVEATS: Initial data are expected to come from studies of patients with relatively severe COVID-19. Because antivirals work best when patients are healthier, those results may show limited effectiveness.

STATUS: Repurposed Experimental

EARLY RESULTS: 0-3 months

HYDROXYCHLOROQUINE / CHLOROQUINE

Malaria drug also believed to have antiviral activity. Blocked SARS-CoV-2 entry into cells in an in-vitro experiment. In one small French study, some COVID-19 patients showed improvements but there was no way to know if the drug was the reason. Results published in April from another study in France and one in China found no benefit in patients treated with the drug. Dozens more clinical studies are underway around the world.

STATUS: Repurposed

EARLY RESULTS: 0-3 months

VACCINES

MRNA 1273 - MODERNA/NIAID

RNA vaccine made with messenger-RNA (mRNA) encoding the spike protein of SARS-CoV-2 encapsulated in a lipid nanoparticle. The phase 1 trial with 45 subjects aged 18-55 at three locations in the United States will evaluate the vaccine’s safety and provide early data on the immune response it induces. Trial completion is anticipated to be June 1, 2020.

STATUS: Experimental

EARLY RESULTS: 0-3 months

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*NON-DRUG THERAPIES*

CONVALESCENT PLASMA

Blood plasma from recovered COVID-19 patients is transfused into patients who are currently ill, in the hope the freshly-made antibodies it contains will help fight the virus. The method has been used for more than 100 years and carries little risk of harm or side effects. Small case studies suggest it may help reduce virus levels, and controlled trials are in progress in China, Europe and the United States to gather stronger evidence for a benefit. Results published in April from a study in 10 patients with severe illness in China found significant improvement compared to similar patients who did not receive the treatment.

CAVEATS: Immediately available and already in limited use, but supply of plasma from recovered patients may not be sufficient to meet all needs. Further studies of recovered patients must also determine if everyone produces a full immune response to the infection, including “neutralizing antibodies,” at sufficiently high levels to become donors.

EARLY RESULTS: 0-3 months

SEROLOGY / ANTIBODY TESTING

Governments and academic groups have started to test blood for antibodies indicating that a person has been exposed to the new virus, with or without showing symptoms. The presence of antibodies indicates past infection, but separate, ongoing research is needed to know what type and concentration of virus-neutralizing antibodies protect against a new infection, whether all infections produce a full antibody response, and how long protection might last.

Wide serology testing for antibodies will soon provide a broader understanding of the scope and dynamics of the pandemic, help identify which recovered patients may have some immunity to reinfection and for how long, and also help identify the neutralizing antibodies that could become templates for monoclonal antibody therapies as well as models for desired responses from a vaccine candidate. Data from serology testing are expected to begin appearing within weeks.

CAVEATS: Early data on COVID-19 patients in China suggests that most develop varying amounts of antibodies in response to infection. One pre-publication report analyzed plasma from 175 patients and found that a sign of inflammation correlated with higher antibody titers and that younger patients were less likely to produce large amounts of antibodies.

Experts think instances of “reinfection” in recovered patients are more likely relapses in patients whose bodies had not cleared the virus. Data is still lacking on whether mild or symptomless infections generate meaningful antibody responses or protection.

STATUS: Experimental

EARLY RESULTS: 0-12 months