(Bloomberg) -- As Covid-19 again surges across the US, many people are going without time-sensitive therapeutics like Paxlovid because doctors worried about shortages are reluctant to prescribe the drugs. But the situation has changed and supplies are now abundant.

Paxlovid, a combination of pills taken for five days, cuts the risk of hospitalization by nearly 90%, according to the manufacturer, Pfizer Inc. But to be effective, it must be taken within five days of the onset of symptoms—which include everything from a scratchy throat, runny nose, cough and chills to fever, body aches, headache, nausea, vomiting, diarrhea, difficulty breathing and loss of taste or smell.The Food and Drug Administration has issued emergency-use authorizations for the drug to treat mild to moderate Covid-19 in people who are at high risk. The Centers for Disease Control and Prevention defines those as individuals ages 50 years or older, unvaccinated, or with certain medical conditions like kidney, liver, lung and heart disease, diabetes, cancer and HIV. It also recommends the drug for people who are immunocompromised, pregnant, obese, cigarette smokers or suffering from mood disorders.

In March, the Biden administration launched a nationwide initiative to provide quick access to Paxlovid and other oral antivirals. Through this program, people can go to one site to get tested for Covid-19 and a get a prescription filled the same day. These one-stop locations can be found by using the Department of Health and Human Services’ Test to Treat Locator or by calling 1-800-232-0233.Some of the nation’s largest pharmacy chains are participating, including CVS Health Corp., which has 1,200 MinuteClinics inside select stores in 35 states and Washington.

“The number of patients being prescribed oral antiviral medications at our MinuteClinic locations has increased steadily over the last three months,” the company said in an email. Paxlovid, along with Merck & Co.’s Covid pill, molnupiravir, are available at almost all of CVS's pharmacies, the company said.

Yet critics of the program say these lifesaving drugs aren’t getting to those who need them most.In March, NPR reported that a large percentage of the pills the government supplied to pharmacies for free were sitting on store shelves. CNN found that the government’s site-locator tool was missing key locations like the Zuckerberg San Francisco General Hospital, which also offers test-to-treat services

©2022 Bloomberg L.P.