Imagine walking into a pharmacy for a COVID test — and leaving with a free treatment.

That's the vision behind President Biden's ambitious "Test to Treat" initiative, announced at Tuesday's State of the Union address, which aims to provide a quick and easy way to reduce illness.

But successful execution of this "one-stop shop" plan – rolled out later this month at CVS, Walgreens and other retail and long-term care facility pharmacies – will be challenging, say experts.

"We need a much better supply of anti-COVID pills, accurate tests, and solid coordination with pharmacists to pull this off," tweeted Scripps Research executive vice president Eric Topol.

Pfizer's antiviral pill, called paxlovid, reduces the risk of hospitalization or death by 89% if provided within five days of symptoms. It is also assumed to reduce the risk of viral transmission.

It's the most important step the U.S. can take to prepare for a future surge, tweeted Dr. Bob Wachter,  professor and chair of the Department of Medicine at UCSF.  Of possible strategies, "if I had to choose, it'd be access to Paxlovid… from test to start (treatment) in one day."

By skipping a doctor's visit, the new approach — part of The White House's 96-page coronavirus strategy, unveiled on Wednesday — could transform a process that is currently slow and burdensome.

"Early 'same day' treatment after a positive test for any infectious disease – particularly respiratory viral ones like COVID and flu – has long been a North Star goal in medicine, especially at scale," according to Dr. Vin Gupta, professor of Health Metrics Sciences at the Institute for Health Metrics and Evaluation at the University of Washington.

CVS and Walgreens do not yet have a start date or estimated number of locations for the program's rollout. But they endorsed the effort.

"With our MinuteClinic retail clinics and CVS Pharmacy footprint we are uniquely positioned to help support the Government's Test to Treat initiative and look forward to helping to provide expanded access as additional inventory becomes available," said Matt Blanchette of CVS Pharmacy.

According to Walgreens spokesperson Karen May, "we look forward to continuing to work closely with the administration and federal agencies on the latest guidance allowing our on-site provider partners to assess patients and order oral COVID-19 therapies."

What would it take for the program to work?

• Adequate supplies of medication. At present, there aren't enough pills for everyone. This means that a pharmacist must decide, based on someone's medical history, who meets the criteria for treatment. But pharmacists don't have access to private medical records. And the patient may not know whether they're high risk.

This will improve, over time. Biden announced that more than a million doses of the pills will be available this month. More than twice as many will be available in April.

• Authorizing pharmacists to write drug prescriptions. With over 85% of Americans living within five miles of a community pharmacy, pharmacists are often the closest healthcare provider. But currently, many pharmacists aren't empowered to give the pill.

In California, pharmacists must have a "Collaborative Practice Agreement" with a doctor to provide treatment such as hormonal contraception, smoking cessation, vaccinations and naloxone, which reverses an opioid overdose, according to Susan Bonilla, CEO of the California Pharmacists Association. COVID therapy would need to be added to this list.

Pharmacists who hold an "advanced practice pharmacist" license are authorized to give therapies, if they connect with the patient's doctor.

• Faster and more accurate tests. Pharmacies' quick "antigen tests," with results available in 10 to 15 minutes, correctly detect infection in about only about 72% of people with symptoms and 58% of people without symptoms. The tests are even less accurate when used in the first day or two of infection. So people may go home empty-handed.

PCR tests are much more sensitive — but because they must be sent to a lab for processing, they're impractical for someone waiting at a pharmacy.

• Careful screening of patients. Not everyone should get the pill, because it can cause severe interactions with many common medicines, including blood thinners, some antidepressants and cholesterol-lowering drugs like Zocor.

"Considerable effort is required to sort out these potentially dangerous drug-drug interactions," said Dr. Derek Eisnor, who serves as HHS's lead for the allocation and distribution of the COVID-19 therapeutics, in a recent webinar.

The pill is also also off-limits for patients with some kidney or liver impairments.

• Pharmacies need to be better staffed, and better paid, for this new responsibility.

There's a labor shortage at pharmacies, and employees say they're under intense strain as their workload has soared due to vaccination and testing. A January survey from the American Pharmacists Association  found that 74 percent of respondents said they didn't have enough time to safely perform patient care and clinical duties. The number of job postings for pharmacists jumped from 12,600 in 2020 to 15,000 in 2021.

Even without this new role, pharmacies are operating with fewer workers and reduced hours, compared to pre-pandemic times.

"It will be important for the government to ensure that Medicare will reimburse pharmacists for clinical services related to this treatment," said Bonilla.

• Pharmacies could become superspreader sites. It's a bad idea for contagious people to cluster indoors while waiting for test results — especially if they're in the company of elders, the immunocompromised and everyone else picking up a prescription. Besides, sick people want to stay home.

Perhaps pharmacies would design a safe drive-through site. Or telemedicine could be used, linking treatments to at-home tests.

The initiative could help usher in a "new normal," where treatment is routine and the virus no longer dominates everyday life, said experts. But much remains to be worked out.

"It is not just a one simple strategy," said Dr. Meg Sullivan, Acting Chief Medical Officer for the Office of the Assistant Secretary for Preparedness and Response. "It is multiple different efforts."