COVID-19 antiviral drugs in short supply

key takeaways

  • Two oral antiviral treatments designed to reduce the severe consequences of COVID-19 in high-risk groups received emergency use authorization in late December.
  • Although manufacturers have ramped up production, supplies remain low and likely cover only a small percentage of COVID-19 patients.
  • Clinicians continued to rely on monoclonal antibodies until antiviral drugs became more widely available.

The FDA-authorized COVID-19 antiviral pill has been praised for saving lives and reducing the burden on the U.S. health system from soaring hospitalizations and staffing shortages.

But some experts worry that initial supplies of these drugs are too thin to provide significant support during the Omicron surge.

For people at risk for severe COVID, the risk of hospitalization can be reduced if treatment is taken early in the course of the illness. Unlike other COVID-19 treatments that must be given intravenously, patients can take antiviral pills at home to avoid serious illness.

“The use of these antivirals really has the potential to help reduce the severity of illness, hospitalizations and deaths, and to some extent change how we feel about COVID in general in this country right now,” Ronald Lubelchek, MD, an infectious disease physician, said in Cook. The county’s John H. Stroger, Jr. Hospital told VigorTip.

Pfizer’s COVID-19 antiviral reduces hospitalizations and deaths by 89%

Oral antiviral drug could be a ‘game changer’

The U.S. Food and Drug Administration (FDA) granted emergency use authorizations for Pfizer’s Paxlovid and Merck’s molnupiravir in late December.

These drugs are designed to slow disease progression and reduce the chance of hospitalization. Each course of treatment consists of 30 and 40 tablets respectively, taken for 5 days.

In clinical trials, Paxlovid reduced hospitalizations and deaths by nearly 90% in people at high risk for COVID-19, The result was touted as a “game changer” by President Joe Biden.

In the final analysis, molampiravir was approximately 30% effective in reducing COVID-19 hospitalizations and deaths. Monupiravir can be used to treat mild to moderate cases when alternative treatment options are not available, the FDA said.

Doctors may prescribe an oral antiviral drug for patients at high risk of becoming seriously ill from COVID-19.

The National Institutes of Health outlines which patients are most likely to be hospitalized and die from COVID-19 in health system guidelines to provide the most vulnerable populations with a limited supply of antiviral drugs.

The first tier includes immunocompromised individuals, such as those undergoing solid organ transplantation or chemotherapy. Unvaccinated people over 75 years or 65 years and older with additional risk factors such as diabetes, cardiovascular disease, hypertension, chronic lung disease were also prioritized.

In some areas, state and local health systems can set their own guidelines. Lubelchek said his hospital follows a grading system outlined by the Illinois Department of Public Health. The first tier under the system also includes obese people aged 12 and over and pregnant women.

“Given the current burden of COVID, we can’t cover everyone who is eligible for Tier 1 with these oral therapies,” Lubelchek said. “The providers who prescribe it first, and the patients they serve, will be those who may use it and get its people.”

Antiviral pills are a drop in the bucket

The federal government has purchased more than 3 million courses of molnupiravir and nearly 450,000 courses have been distributed so far.

In early January, the White House announced it would buy 20 million Paxlovid courses, saying the first 10 million courses would be available by the end of June. About 117,000 courses have been offered nationwide.

Rajesh Gandhi, MD, an infectious disease physician at Massachusetts General Hospital and a professor of medicine at Harvard University, told VigorTip that the oral antiviral drug arrived at pharmacies across Massachusetts just last week, and he has yet to prescribe it to his patients.

“Hopefully there will be more after the first shipment, but there is no doubt that in a very short period of time – the next week or two – demand will far exceed supply,” Gandhi said.

The White House is distributing oral antivirals to states based on population, and states will decide how to distribute the treatment to pharmacies and health systems. As of Tuesday, the most populous state of California had received 45,750 courses of Paxlovid or molnupiravir. Wyoming, the state with the smallest population, received 920, according to the Department of Health and Human Services.

Some leaders in hard-hit areas have raised concerns about the strategy, saying areas with a surge in COVID-19 cases should prioritize drug delivery.

“The federal government shouldn’t be distributing them across the board. They should be looking at where they’re most needed,” Sen. Chuck Schumer from New York said at a news conference last week.

New York State has received 33,620 courses to date. Meanwhile, the state averaged more than 62,000 cases a day for seven days.

More than 200 federally funded community health centers will also receive antiviral drugs and distribute them to vulnerable populations.

“We want to ensure that those at greatest risk have access to medicines, and we are fair in the distribution of medicines so that those who are disproportionately affected and who have traditionally had less access to care have access to these medicines,” Gandhi said.

Address supply shortages

In a statement this month, President Biden acknowledged the scarcity of oral antivirals and said his administration was working to increase production. He said it would take “months” to produce Paxlovid pills because of its “complex chemistry.”

Paxlovid consists of two ingredients: nirmatrelvir and ritonavir. Nirmatrelvir is a protease inhibitor that prevents the COVID-19 virus from multiplying by blocking a key enzyme in infected cells. Ritonavir supports this process by preventing other enzymes from destroying nirmatrelvir. When the virus is prevented from replicating, it can reduce the viral load and reduce the severity of the disease.

For more than two decades, ritonavir has been used to treat diseases such as AIDS. But nirmatrelvir is a new formulation, and manufacturers may not be able to scale up production anytime soon.

Dr. Kris White, assistant professor of microbiology at the Icahn School of Medicine at Mount Sinai, told VigorTip that nirmatrelvir’s complex chemistry determines the drug’s effectiveness.

White, who worked with Pfizer on a clinical trial of Paxlovid, said that while simpler formulations in the future may be as effective as current formulations, increasing supply in the short term will depend on manufacturers ramping up production.

Both Paxlovid and monupavir were most effective during the first five days after the onset of COVID-19 symptoms. During the first few days after infection, as the virus replicates in the body, drugs can slow its reproduction. After five days, symptoms were largely driven by the body’s immune response to the infection, and the treatment lost most of its efficacy.

“The sooner you get them, the better,” White said. “People should know that if they have risk factors and they test positive, they should immediately start looking for these drugs as quickly as possible.”

“Right now, you may not find them, but in the next few weeks and months you will find them, and that makes a big difference,” he added.

Monoclonal antibodies remain key for high-risk patients

In addition to antiviral pills, there are treatments that can be effective in preventing hospitalization due to Omicron infection. GlaxoSmithKline’s monoclonal antibody sotrovimab is one of the few treatments proven to be effective against Omicron, according to some recent preprint studies.

Sotrovimab, authorized by the FDA in December 2021, was 85 percent effective in preventing hospitalizations in clinical studies. GSK announced that it will deliver 600,000 doses of the treatment over the next few months.

Remdesivir was one of the first monoclonal antibodies approved to treat COVID-19, and clinicians are looking for new infusion strategies to use the drug to relieve severe disease in patients.

Given its relative abundance, Gandhi said, clinicians may offer remdesivir to patients who have tested positive for COVID-19 but have been hospitalized for different conditions.

Oral antivirals are logistically preferable, Gandhi said, as patients can self-administer the medication at home. But given the efficacy of sotrovimab and remdesivir in preventing serious outcomes, and the current shortage of oral options, intravenous options will continue to play a key role in minimising serious disease outcomes over the next few weeks.

“While we are happy to use oral drugs, we also use intravenous therapy,” Gandhi said.

In states where Delta is still responsible for most of the cases, the federal government is still shipping monoclonal antibodies from companies like Eli Lilly and Regeneron that don’t appear to work against Omicron.

“At this moment, we have no choice,” White said. “[Monoclonal anitbodies] When no one can use Paxlovid, our only cure is until they can produce more Paxlovid. “

what does this mean to you

If you are at high risk for severe COVID-19, oral antiviral medication can minimize the chance that you will need to be hospitalized. If you have flu- or cold-like symptoms, get tested right away and ask your care provider if a prescription for Paxlovid or molnupiravir is right for you.

The information in this article is current as of the date listed, which means that you may have updated information as you read this article. For the latest updates on COVID-19, visit our Coronavirus news page.