Why Not Everyone Should Take Paxlovid

It’s getting harder to avoid COVID-19, thanks to the dominance of BA.5 in the U.S. and the growing number of other Omicron subvariants. Fortunately, Pfizer’s antiviral treatment Paxlovid can minimize illness from the disease.

But it’s not meant for everyone. Only those who are at increased risk for severe disease from COVID-19 qualify for the drug, including people over age 12 who have weakened immune systems or other health conditions that increase risk of serious effects of COVID-19—like asthma, cancer, liver disease, lung disease, heart disease, and obesity. Paxlovid also comes with a list of potential adverse reactions with common drugs, such as cholesterol-lowering statins.

Because the drug is not approved by the U.S. Food and Drug Administration, but allowed under an emergency use authorization, doctors generally can’t prescribe it outside of the authorization criteria. Yet that’s not stopping people of all ages and risk profiles from asking for Paxlovid, which went from hard-to-find to much more accessible in just a few months. From December 2021, when Paxlovid was authorized, to June 2022, prescriptions for the drug have jumped from 2,500 to nearly 1 million in the U.S., according to data provided to TIME by health-data company Iqvia.

Here’s what prescribers say about who should get Paxlovid at this point in the pandemic.

People at higher risk benefit more

Studies conducted by Pfizer before Paxlovid was authorized have found that the drug reduces the risk of hospitalization and death by up to 89% among unvaccinated people at high risk for bad COVID-19 outcomes. That efficacy has become less impressive as vaccination has increased: the company’s latest data show that Paxlovid is about 57% effective at achieving these outcomes in vaccinated people at lower risk of severe illness, such as those who have at least one of the risk factors that raise the risk of serious COVID-19 illness.

Other data that Pfizer released in June showed that the drug doesn’t significantly reduce the number of symptoms among people of any vaccination status who are at moderate risk of severe disease, compared to those not taking it. “That data changed how I see the medication, which was once hailed as a game changer,” says Dr. Anand Viswanathan, assistant professor of medicine at NYU Langone Health.

Even after the drug was authorized by the U.S. Food and Drug Administration (FDA) in December 2021, supplies were scarce, but the Biden Administration raised awareness and access to Paxlovid in March by announcing the Test to Treat program, which allowed people to get tested at places like pharmacies and receive a prescription on the spot if they were positive. Supply of the drug increased by the spring, and it went from being under-prescribed (in order to reserve limited supplies for people at highest risk) to popular among doctors and patients. On July 7, the FDA further expanded access by allowing state-licensed pharmacists to write prescriptions for anyone over age 12.

With improved access, some experts believe the drug may now be overprescribed. Paxlovid is still one of only a few COVID-19 antiviral treatments authorized by the FDA (others include a pill called molnupiravir and remdesivir, an IV therapy) so people are still asking for it. “There is probably some overprescribing or prescribing in low-risk people,” says Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security and an infectious disease physician.

Despite the drug’s increased popularity, for people who are otherwise healthy and not at high risk of getting severely ill, there are limited data supporting the benefits of taking antivirals like Paxlovid. “For the average healthy person—even a 55 year old with no major medical problems—they might not benefit and just complain of the bad taste in their mouth,” which is a common side effect of Paxlovid, says Adalja. “You have to go back to the primary purpose of prescribing Paxlovid: to prevent severe disease, hospitalization, and death.”

Prescribing by age

Even for people with symptoms who don’t have other health conditions, Adalja generally doesn’t prescribe Paxlovid unless they are ages 65 or older. That’s a common yardstick that doctors are starting to use. But there are no hard and fast rules, even when it comes to age. Dr. William Durkin, an emergency physician at Alvarado Medical Center in San Diego, recently decided not to prescribe Paxlovid to an older patient who was otherwise healthy and did not have any symptoms.

For such patients who don’t have symptoms when they test positive, doctors may write a prescription proactively and tell them to reach out if they do develop symptoms in a day or so. Because Paxlovid is most effective if taken within five days of symptoms appearing, having the prescription ready could ensure that people take advantage of the short window in which the drug works.

The future of Paxlovid

Used properly, an antiviral like Paxlovid can help to slow transmission as the highly contagious Omicron variants continue to spread. “We have been working diligently with clinicians, community organizations, and the general public to make people aware that these medications are available and how important it is to know your risk factors for severe COVID-19 disease,” says Dr. Mary Mercer, associate professor of emergency medicine at the University of California San Francisco and Zuckerberg San Francisco General Hospital and Trauma Center. By limiting the amount of severe disease in communities, the drug is another way to keep the virus under control.

Should a new variant appear that is even better at evading the protection afforded by vaccines, and which causes more serious disease even among the vaccinated, then “Paxlovid may find itself back in the role of game changer,” says Viswanathan.