WHO recommends Paxlovid for patients with 'non-severe' COVID-19

April 21 (UPI) -- The World Health Organization strongly recommends Pfizer's oral antiviral drug Paxlovid for people with mild to moderate COVID-19 who are at the highest risk for developing severe illness and needing hospital treatment, officials with the agency announced Thursday.

Paxlovid, which combines two antiviral drugs, nirmatrelvir and ritonavir, can be used to treat those at increased risk for developing severe COVID-19, including the unvaccinated or older adults, the agency's Guideline Development Group said in an article published Thursday by The BMJ.

It can also be used in infected patients with weakened immune systems due to cancer or other underlying health conditions, they said.

It should also be made available in places where COVID-19 vaccine supplies have been limited, such as in the global south, according to the organization.

"Antiviral drugs should be administered as early as possible in the course of the disease," the WHO said in a statement.

"Access to these drugs is tied to the access to [COVID-19] diagnostic tests, especially for those targeting the early phase of disease," it said.

This recommendation is based on data from two clinical trials involving more than 3,000 participants, according to the agency's Guideline Development Group.

In these studies, treatment with Paxlovid lowered participants' risk for hospitalization 85%, they said.

The Food and Drug Administration granted Pfizer and emergency use authorization for Paxlovid in December.

Under that authorization, the drug can be used for treating mild to moderate COVID-19 in adults and children age 12 years and older who weigh at least 88 pounds and are at high risk for progression to severe disease, the agency said.

Paxlovid is available by prescription only and should be initiated as soon as possible after diagnosis of COVID-19 and within five days of symptom onset, it said.

Currently, the United States has stockpiled 20 million courses of the drug, though Pfizer says it will increase supplies to 80 million doses by the end of the year, according to reports.

Concerns remain regarding Paxlovid's availability in low- and middle-income countries, the WHO said.

Although Pfizer has committed to distributing the drug in nearly 100 poorer nations, the global health agency has accused the company of a "lack of transparency ... [that] is making it difficult for public health organizations to obtain an accurate picture of the availability of the medicine."

In addition, a licensing agreement made between Pfizer and the global Medicines Patent Pool, in which drug composition information is shared, "limits the number of countries that can benefit from generic production of the medicine," it said.

In the new recommendations released Thursday the WHO's Guideline Development Group said Paxlovid "likely represents a superior choice ... because it may prevent more hospitalizations than the alternatives."

Pfizer's drug also has fewer potential harms than the antiviral drug molnupiravir, which is manufactured by Merck, and is easier to administer than intravenous options such as remdesivir and antibody treatments, or those that use donated or lab-created immune proteins, they said.

However, they recommend against its use in people at lower risk for severe COVID-19, as the benefits for these patients "are trivial," and they make no recommendation for patients with severe or critical COVID-19.

This is because Paxlovid has not yet been studied on patients in this latter group, the agency said.

The FDA granted Merck an emergency use authorization for molnupiravir in November, but recommends against its use in people who are pregnant because of side effects.

Merck is allowing makers of generic drugs to manufacture and distribute molnupiravir, which the WHO recommends for high-risk patients with non-severe COVID-19, the company announced in January.

In a guideline update issued Thursday, WHO also makes a conditional recommendation to use the antiviral drug remdesivir for patients with non-severe COVID-19 at highest risk of hospitalization.

This recommendation is based on new data from five clinical trials involving 2,700 patients and replaces a previous recommendation against treatment with remdesivir in all patients with COVID-19, the agency said.

WHO guidelines recommend the use of the monoclonal antibody, or lab-created immune protein, treatments, sotrovimab or casirivimab-imdevimab in selected patients with COVID-19, as well as corticosteroids in those with severe disease.

However, the agency advises against the use of convalescent plasma, or plasma donated by patients who have recovered from COVID-19 and have antibodies against it, as well as ivermectin and hydroxychloroquine.