Scientists around the world are working on a number of vaccines and treatments for COVID-19. Xinhua/Zhang Yuwei via Getty Images
  • Scientists around the world are working on potential treatments and vaccines for the new coronavirus disease known as COVID-19.
  • Several companies are working on antiviral drugs, some of which are already in use against other illnesses, to treat people who already have COVID-19.
  • Other companies are working on vaccines that could be used as a preventive measure against the disease.

With confirmed COVID-19 cases worldwide surpassing 9 million and continuing to grow, scientists are pushing forward with efforts to develop vaccines and treatments to slow the pandemic and lessen the disease’s damage.

Some of the earliest treatments will likely be drugs that are already approved for other conditions, or have been tested on other viruses.

“People are looking into whether existing antivirals might work or whether new drugs could be developed to try to tackle the virus,” said Dr. Bruce Y. Lee, a professor at the CUNY Graduate School of Public Health & Health Policy.

As of May 8, two medications had received emergency use authorization (EUA) from the Food and Drug Administration (FDA): the antiviral remdesivir and a drug used to sedate people on a ventilator.

The FDA issued an EUA in March for the antimalaria drugs chloroquine and hydroxychloroquine, but later revoked it after studies showed that they’re unlikely to be effective in treating COVID-19.

An EUA allows doctors to use these drugs to treat people with COVID-19 even before the medications have gone through the formal FDA approval process.

These drugs are still being tested in clinical trials to see whether they’re effective against COVID-19. This step is needed to make sure the medications are safe for this particular use and what the proper dosage should be.

It could be months before treatments are available that are known to work against COVID-19. It could be even longer for a vaccine.

But there are still other tools we can use to reduce the damage done by the new coronavirus, also known as SARS-CoV-2.

“Even though technological advances allow us to do certain things more quickly,” Lee told Healthline, “we still have to rely on social distancing, contact tracing, self-isolation, and other measures.”

Searching for effective treatments

Drug development is sometimes described as a pipeline, with compounds moving from early laboratory development to laboratory and animal testing to clinical trials in people.

It can take a decade or more for a new compound to go from initial discovery to the marketplace. Many compounds never even make it that far.

That’s why many medications being eyed as potential treatments for COVID-19 are drugs that already exist.

In a review in the British Journal of Pharmacology, scientists from the United Kingdom called for wider screening of existing drugs to see if they might work against the new coronavirus.

They identified three stages of infection at which the virus could be targeted: keeping the virus from entering our cells, preventing it from replicating inside the cells, and minimizing the damage that the virus does to the organs.

Many of the drugs being developed or tested for COVID-19 are antivirals. These would target the virus in people who already have an infection.

Lee says antivirals work better if you administer them sooner, “before the virus has a chance to multiply significantly.” And also before the virus has caused significant damage to the body, such as to the lungs or other tissues.

Dr. Robert Amler, dean of the School of Health Sciences and Practice at New York Medical College and a former chief medical officer at the Centers for Disease Control and Prevention (CDC) Agency for Toxic Substances and Disease Registry (ATSDR), says both antivirals and vaccines will be valuable tools in combating COVID-19.

However, he told Healthline that “antivirals are likely to be developed and approved before a vaccine, which typically takes longer.”



Developed a decade ago, this drug failed in clinical trials against Ebola in 2014. But it was found to be generally safe in people. Research with MERS, a disease caused by a different coronavirus, showed that the drug blocked the virus from replicating.

The drug is being tested in many COVID-19 clinical trials around the world. This includes studies in which remdesivir is being administered alongside other drugs, such as the anti-inflammatory drug baricitinib.

The drug is also being tested in children with moderate to severe COVID-19.

In late April, the drug’s manufacturer, Gilead Sciences, announced one of its trials had been “terminated” due to low enrollment. Gilead officials said the results of that trial had been “inconclusive” when it was ended.

A few days later, the company announced that preliminary data from another trial of remdesivir overseen by the National Institute of Allergy and Infectious Diseases (NIAID) had “met its primary endpoint.”

Dr. Anthony Fauci, the institute’s director, told reporters the trial produced a “clear cut positive effect in diminishing time to recover.” He said people taking the drug recovered from COVID-19 in 11 days compared with 15 days for people who didn’t take remdesivir.

More details will be released after the trial is peer reviewed and published.

Gary Schwitzer, founder of, though, said the researchers changed the primary endpoint 2 weeks before Fauci’s announcement.

Schwitzer compared that to moving football goalposts closer to make it easier to get a touchdown.

At the same time, another study published in The Lancet reported that participants in a clinical trial who took remdesivir showed no benefits compared to people who took a placebo.

Despite the conflicting results, the FDA issued an order on May 1 for the emergency use of remdesivir.

In early June, federal officials announced their supply of remdesivir will run out by the end of June. Gilead is ramping up production, but it’s unclear how much of the drug will be available this summer.

In mid-July, Gilead officials announced results from an ongoing phase III trial of remdesivir. They said the drug was “associated with an improvement in clinical recovery and a 62 percent reduction in the risk of mortality compared with standard of care.” They called it an an “important finding that requires confirmation in prospective clinical trials.”


This antiviral was tested along with the drug lopinavir/ritonavir as a treatment for COVID-19.

Researchers reported in mid-April that the two drugs didn’t improve the clinical outcomes for people hospitalized with mild to moderate cases of COVID-19.


This drug was created by scientists at a nonprofit biotech company owned by Emory University.

Research in mice has shown that it can reduce replication of multiple coronaviruses, including SARS-CoV-2.

Pharmaceutical company Merck and Ridgeback Biotherapeutics LP signed an agreement in May to develop this drug. It’s already being tested in a clinical trial in the United Kingdom. 

Unlike remdesivir, EIDD-2801 can be taken orally, which would make it available to a larger number of people.


This drug is approved in some countries outside the United States to treat influenza.

Some reports from China suggest it may work as a treatment for COVID-19. These results, though, haven’t been published yet.

Japan, where the medication is made, is sending the drug to 43 countries for clinical trial testing in people with mild or moderate COVID-19. Canadian researchers are testing to see whether the drug can help fight outbreaks in long-term care homes.


This is a combination of two drugs — lopinavir and ritonavir — that work against HIV.

Clinical trials are being done to see whether it also works against SARS-CoV-2.

One small study published May 4 in the journal Med by Cell Press found that lopinavir/ritonavir didn’t improve outcomes in people with mild or moderate COVID-19 compared to those receiving standard care.

Another study, published May 7 in the New England Journal of Medicine, found that the drug combination wasn’t effective for people with severe COVID-19.

But another study found that people who were given lopinavir/ritonavir along with two other drugs — ribavirin and interferon beta-1b — took less time to clear the virus from their body. This study was published May 8 in The Lancet.

Merimepodib (VX-497)

This drug developed by ViralClear Pharmaceuticals Inc. has been shown previously to have antiviral and immune-suppressing effects. It was tested against hepatitis C but had only modest effects

The company is running a phase II trial of this drug. People with advanced COVID-19 will be randomized to receive either merimepodib with remdesivir, or remdesivir plus a placebo.

The company hopes to have results by late summer of this year.

Other treatments

Scientists are also looking at other ways to target the virus or treat the complications of COVID-19.

Among them is ibuprofen.

In early June, scientists started a clinical trial to see whether the pain medication could be used for people hospitalized with COVID-19.

Their theory is ibuprofen’s anti-inflammatory qualities could help ease breathing difficulties associated with the illness.

In mid-July, scientists in the United Kingdom reported success in initial tests with a protein called interferon beta. The protein is produced by the body during viral infections.

The researchers said the protein is inhaled directly into the lungs of someone infected with the novel coronavirus in hopes of stimulating an immune response.

They said the protein reduced the odds of developing a severe form of the disease in hospitalized patients by 79 percent.

In late July, researchers at Columbia University in New York announced some initial success in using a cocktail of antibodies to potentially treat people infected with the novel coronavirus.

They said the antibodies were collected from people hospitalized with COVID-19. The drug cocktails were tested on human cells as well as hamsters.

If proven safe and effective, the antibodies would be given via blood transfusions to people newly infected with the virus.

Monoclonal antibodies

These drugs trigger the immune system to attack the virus. Like antibodies made by the body’s immune system, these laboratory-made molecules target a specific invader, such as SARS-CoV-2.

The small biotech company Sorrento Therapeutics announced it has an antibody drug that has been effective in early testing in blocking SARS-CoV-2.

The company say the drug could potentially be used to treat people with COVID-19 as well as help prevent infection.

AbCellera has isolated 500 unique antibodies from a person who recovered from COVID-19 and is set to start testing them.

Regeneron Pharmaceuticals Inc. is testing a two-antibody combination in four groups: people hospitalized with COVID-19; people with symptoms of the disease but not hospitalized; healthy people at high risk of getting sick with COVID-19; and healthy people who have had close contact with someone with COVID-19.

The company hopes to have results by the fall.

Vir Biotechnology has isolated antibodies from people who survived SARS, another disease caused by a coronavirus. The company is working with Chinese firm WuXi Biologics to test them as a treatment for COVID-19.

Convalescent plasma

Along the same lines, the FDA has announced a process for medical facilities to conduct trials on an experimental treatment that uses blood plasma from people who have recovered from COVID-19.

The theory is that their plasma contains antibodies that will attack this particular coronavirus. 

In late May, researchers reported that 19 of 25 people with COVID-19 who were treated with convalescent plasma transfusions at Houston Methodist Hospital in Texas had improved. Eleven of those patients have been released from the hospital.

In late March, the New York Blood Center began collecting plasma from people who have recovered from COVID-19.

The Mayo Clinic and Michigan State University are also leading convalescent plasma programs.

Immune modulators

In some people with COVID-19, the immune system goes into overdrive, releasing large amounts of small proteins called cytokines.

Scientists think this “cytokine storm” may be the reason certain people with severe COVID-19 develop acute respiratory distress syndrome (ARDS) and need to be put on a ventilator.

Several immune suppressants are being tested in clinical trials to see whether the drugs can quell the cytokine storm and reduce the severity of ARDS.

In mid-June, U.K. researchers announced that the inexpensive corticosteroid dexamethasone reduced deaths by about a third in people with severe COVID-19 who were on ventilators, and by a fifth in those who needed oxygen support. 

The results haven’t yet been published in a peer-reviewed journal. The drug, though, is already approved for other conditions and can be given orally or intravenously.

Other drugs being tested include baricitinib, a drug for rheumatoid arthritis; CM4620-IE, a drug for pancreatic cancer; and IL-6 inhibitors.

The FDA has also approved a device that filters cytokines out of the blood of patients with COVID-19.

Stem cells

Athersys Inc. began a phase II/III clinical trial that will examine whether the company’s stem cell treatment could potentially benefit people with ARDS.

Mesoblast has also developed a potential stem cell treatment for ARDS. The company is enrolling people with moderate to severe ARDS into a phase II/III clinical trial in the United States.

Hydroxychloroquine and chloroquine

These drugs received emergency use authorization from the FDA at the end of March.

On June 15, the FDA revoked that authorization, citing studies that indicated hydroxychloroquine didn’t significantly help people with COVID-19 and may have caused serious health risks.

At the time of the FDA authorization in March, manufacturer Novartis donated about 30 million doses of hydroxychloroquine and 1 million doses of chloroquine to the nation’s existing Strategic National Stockpile.

The United States is now left with 63 million doses of hydroxychloroquine and 2 million doses of chloroquine in its emergency stockpile.

Clinical results for the drugs have been mixed. Studies published in May in the New England Journal of Medicine and Journal of the American Medical Association showed that the drugs didn’t help people with COVID-19.

In late May, the World Health Organization announced it was halting its clinical trials of hydroxychloroquine due to safety concerns.

In mid-June, the National Institutes of Health halted its clinical trial of hydroxychloroquine after data showed that the drug was no better than an inactive placebo.

In late June, British officials announced they would restart a global clinical trial on hydroxychloroquine and chloroquine.

In late July, scientists in Brazil announced that hydroxychloroquine given alone or with other drugs did not improve the condition of people hospitalized with mild to moderate COVID-19 illnesses.

Next steps for treatments

While a lot of the focus is on developing new treatments for COVID-19, improvements in how doctors care for patients using existing technology are also crucial.

“The things that we have to worry about with the novel coronavirus is that it can cause pneumonia and acute respiratory distress syndrome,” Lee said. “There are ways of treating those things that can reduce the effects, so doctors are trying to use those as well.”

No company has offered a timeline for when its drug might be used more widely to treat COVID-19. This isn’t an easy thing to estimate.

After laboratory and animal testing, drugs have to pass through several clinical trial stages before they can be approved for widespread use in people.

It’s also difficult to speed things up, because scientists have to enroll enough people in each stage to have useful results. They also have to wait long enough to see whether there are harmful side effects of the drug.

However, drugs can sometimes be given to people outside a clinical trial through the FDA’s “compassionate use” program. For this to happen, people must have an “immediately life-threatening condition or serious disease or condition.”

Doctors at the University of California, Davis were able to secure this type of approval for a woman with severe COVID-19 to receive remdesivir. They reported she was doing well.

Many will take this as a sign that the drug works. But because the drug was given outside of a clinical trial to just one person, it’s not possible to know for certain. Also, other people may not have the same response to the drug.

Improvements in testing can also reduce COVID-19 deaths by slowing the spread of the virus. As cities and states lift stay-at-home and physical distancing orders, increased testing will be needed to prevent large spikes in infections.

The FDA has granted emergency use authorizations for many diagnostic tests. Companies and universities around the world also continue to develop new ones.

On May 8, the FDA announced the authorization of the first at-home saliva-based COVID-19 diagnostic test.

The test, which was designed by Rutgers Clinical Genomics Laboratory, allows people to spit in a tube at home and mail it back to the Rutgers lab for testing.

This is the first at-home test approved involving saliva collection — all other approved at-home tests are conducted via a nasal swab.

The Rutgers test will hopefully expand access to people unable to easily make it to a clinic or drive-thru testing facility. The test is currently only available by prescription.

New guidelines were posted by the FDA in early May designed to expedite the development and approval of more at-home self-collection kits to further expand access to testing.

Under the new guidance, test developers are encouraged to reach out to the FDA to ensure their kits and shipping methods are in compliance with the most up-to-date regulations.

One commercially available test developed by scientists in Europe can show in 15 minutes whether someone has an infection. The test uses a sample collected with a nasopharyngeal swab inserted into the nose.

A real-world analysis found that the test could detect 6 out of 10 people with an infection. It performed much better at identifying when an infection wasn’t present.

While the test isn’t 100 percent effective, it doesn’t require special reagents or trained laboratory staff to run. This would make it ideal for health clinics or in low- and middle-income countries with few clinical laboratories.

But it would have to be part of a broader testing strategy.


A vaccine is designed to protect people before they’re exposed to a virus — in this case, the new coronavirus SARS-CoV-2.

A vaccine basically trains the immune system to recognize and attack the virus when it encounters it.

Vaccines protect both the person who’s vaccinated and the community. Viruses can’t infect people who are vaccinated, which means vaccinated people can’t pass the virus to others. This is known as herd immunity.

Many groups are working on potential COVID-19 vaccines, with several backed by the nonprofit Coalition for Epidemic Preparedness Innovations (CEPI).

There are more than 100 projects around the world centered on the development of a COVID-19 vaccine. As of May 11, eight candidate vaccines were being tested in clinical trials in people.

An official at the National Institutes of Health said in mid-May that large-scale testing could begin in July, with a vaccine potentially available by January.

Other experts say the more likely timeline is summer or fall 2021.

Here’s a look at some of the projects:

  • Moderna. In March, the company began testing its messenger RNA (mRNA) vaccine in a phase I clinical trial in Seattle, Washington. In mid-May, the company announced the vaccine had produced antibodies in all 45 trial participants in this initial clinical phase. The study included 45 healthy volunteers, ages 18 to 55, who are getting two shots 28 days apart. The company has developed other mRNA vaccines before. Those earlier studies showed that their platform is safe, which allowed the company to skip certain animal testing for this specific vaccine. In early May, the company received permission from the FDA to start a phase II study of its vaccine. The FDA also agreed to fast-track regulatory review of this vaccine if it succeeds in a phase III clinical trial. In late July, Moderna finished the phase II trials and began the phase III clinical trials of their vaccine.
  • Inovio. When COVID-19 appeared in December, the company had already been working on a DNA vaccine for MERS. This allowed the company to quickly develop a potential COVID-19 vaccine. Company officials announced at the end of April that it had enrolled 40 healthy volunteers in its phase I clinical trial. It’s preparing to start a phase II/III clinical trial this summer.
  • University of Oxford in England. A clinical trial with more than 500 participants began in late April. Oxford officials said the potential vaccine has an 80 percent chance for success and could be available as early as September. The vaccine uses a modified virus to trigger the immune system. The university has partnered with pharmaceutical company AstraZeneca. The company reported in mid-May the vaccine was effective against COVID-19 after it was given to six rhesus macaque monkeys. The company expects to begin a late-stage clinical trial by the middle of this year. Officials said in mid-May that if the clinical trial is successful, they could deliver 30 million doses by September.
  • University of Queensland in Australia. Researchers are developing a vaccine by growing viral proteins in cell cultures. They began preclinical testing stages in early April. The phase I trial in people will begin in early July.
  • Pharmaceutical companies. Johnson & Johnson and Sanofi are both working on a vaccine of their own. Johnson & Johnson announced it will begin early stage human clinical trials in July. Pfizer has also teamed up with German biotech company BioNTech to develop a vaccine. In early July, Pfizer announced that the vaccine produced an immune response in people during an early stage clinical trial. They added the vaccine did cause side effects such as fever at higher doses.

Scientists at CanSino Biologics in China are also working on a potential vaccine. In late July, they reported that participants in a phase II trial showed a strong immune response when given the vaccine. However, they noted older adults had a weaker response, suggesting two doses might be needed for that segment of the population.

Advances in genetic sequencing and other technological developments have sped up some of the earlier laboratory work for vaccine development.

However, Fauci told reporters in March that a vaccine won’t be available for widespread use for at least another 12 to 18 months.

This is the timeline to complete the phase III clinical studies.

Others are more optimistic, saying we might see some vaccines by the end of the year.

The Trump administration has been promoting this faster timeline, but two administration officials recently backed away from guaranteeing this.

Fauci wrote in the journal Science in May that multiple successful vaccines may be needed to meet the demand of vaccinating billions of people worldwide.

Even if a vaccine is developed and distributed, it’s unlikely to be completely effective. The measles, mumps and rubella vaccine is effective 97 percent of the time while the seasonal flu vaccine tops out at 60 percent.

Still, even a less-effective vaccine may reduce the severity of disease if someone gets COVID-19.

But some experts are worried that people who get the vaccine may stop doing other measures needed to control the spread of the new coronavirus, such as handwashing and staying home when sick.

Speeding up vaccine development

Some scientists argue that a “human challenge trial” could speed up the vaccine clinical trials — potentially shaving months off the timeline.

In this type of trial, healthy volunteers are given a potential vaccine and then intentionally infected with the virus.

Usually, researchers wait for a person given a test vaccine to naturally contract the virus. Then they look at how well the person was protected by the vaccine.

There are no plans for this kind of study in the United States, but nearly 30,000 people in more than 140 countries have signed up to take part.

A human challenge trial raises many ethical questions. One is that there’s still a lot we don’t know about this virus and disease, including who will get seriously ill or die from COVID-19.

That means people can’t really know the risks of participating in the study, so they wouldn’t be able to give high-quality informed consent. This is an essential part of modern clinical trials.

Given the scope of the pandemic, though, some experts think this type of trial will happen eventually.

In preparation for this, the World Health Organization recently released ethical guidelines to navigate these tricky waters.

Meanwhile, some clinical trials are underway in Israel, the Netherlands, and Australia to see whether existing vaccines for tuberculosis might also protect against SARS-CoV-2.

The polio vaccine is another possible option. Scientists think these vaccines might boost the immune system just enough to fight off the new coronavirus, although there’s no evidence yet to confirm this theory.

Two U.S. researchers suggest that the measles, mumps, rubella (MMR) vaccine might offer protection against inflammation and sepsis in people with COVID-19. They recommend starting a clinical trial with the MMR vaccine in healthcare workers.

There’s no guarantee any of the vaccine candidates will work.

“There’s a lot of uncertainty with vaccine development,” Lee said. “Naturally, you have to make sure the vaccine is safe. But you also have to make sure the vaccine will elicit enough of an immune response.”

Like drugs, potential vaccines have to pass through the same clinical trial stages. This is especially important when it comes to safety, even during a pandemic.

“The public’s willingness to back quarantines and other public-health measures to slow spread tends to correlate with how much people trust the government’s health advice,” Shibo Jiang, a virologist at Fudan University in China, wrote in the journal Nature.

“A rush into potentially risky vaccines and therapies will betray that trust and discourage work to develop better assessments,” he wrote.

Clinical trial stages

  • Phase I. The drug is given to a small number of healthy people and people with a disease to look for side effects and figure out the best dose.
  • Phase II. The drug is given to several hundred people who have the disease, looking to see whether it works and if there are any side effects that weren’t caught during the initial testing.
  • Phase III. In this large-scale trial, the drug is given to several hundred or even up to 3,000 people. A similar group of people take a placebo, or inactive compound. The trial is usually randomized and can take 1 to 4 years. This stage provides the best evidence of how the drug works and the most common side effects.
  • Phase IV. Drugs that are approved for use undergo continued monitoring to make sure there are no other side effects, especially serious or long-term ones.

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