Nearly 600,000 courses of Pfizer’s Covid antivral pill Paxlovid are currently sitting on pharmacy shelves unused, official statistics show. 

Data from the U.S. Department of Health revealed the piling up stocks of the drug, which slashes the risk of hospitalization for vulnerable people who catch Covid. 

There are also 200,000 courses of AstraZeneca’s Covid antibody drug Evusheld now waiting to be distributed, while more than a million doses of Merck’s antiviral pill Lagevrio are now available. 

The White House’s chief medical adviser, Dr Anthony Fauci has already admitted that supplies of the drugs are being ‘underutilized’ across the country.

Experts suggest too few doctors are aware that the treatments — which are only available on prescription — are in stock.

They say a lack of Covid testing — leaving many infections unconfirmed — and the pills being available to too few people are also behind the low usage rates. 

It comes amid a rise in cases in the US, which were are up 38 percent over the past week. But hospitalization and death figures remain low. 

The federal Government has purchased millions of doses of the Covid-fighting treatments. 

Only last month President Joe Biden pledged to get the drugs to everyone that needed them free of charge.

But statistics suggest that despite the treatments becoming available nationwide, they are failing to reach many Americans. 

One of the pills available is Paxlovid — an antiviral pill that works by stopping the virus replicating, giving the body time to fight off an infection.

It is available on prescription across the U.S., and involves taking three tablets twice a day for five days.

It is also free to Americans, with the Federal Government footing the bill of $530 for each course.

Clinical trials showed it slashed hospitalization rates by 89 percent among at-risk people who took it within three days of developing Covid symptoms. Some of these patients were vaccinated.

The drug was approved for over-12s with mild or moderate Covid who were at risk from the virus in December. 

But supplies were initially hard to come by, until in recent weeks packets began stacking up on shelves.

Dr Ryan Maves, an infectious diseases expert at Wake Forest School of Medicine in North Carolina, warned few doses were being prescribed because doctors were unaware that the pill is available.

He told NBC News: ‘I think part of the challenge is so early on there was such little supply, and getting ahold of it was a real challenge.

‘But the folks caring for patients who are at high risk may not know it is so much easier to get now.’

Dr Paul Sax, an infectious diseases expert at Harvard Medical School, warned too few pills were being used because of a lack of Covid testing leading to many infections going undiagnosed.

He added that the categories for people to be treated were also too narrow, leading to many not receiving the drugs who could benefit from them.

There have also been problems rolling out Evusheld which, unlike Paxlovid, is meant for immunocompromised patients who have been exposed to Covid but not yet developed symptoms of the virus.

The treatment is available on prescription, and should be given as two injections commonly in each buttocks. 

Scientists say it can spark up to six months of protection from catching the virus.

It was approved by the FDA for immunocompromised over-12s in December, but again, many doses are remaining on shelves.

Janet Handal, who runs an advocacy group for the immunocompromised, told CNN that like with Paxlovid, many doctors were also unaware of this treatment. 

‘We’ve had people in our group call their doctor and ask about Evusheld and been told, “what’s that?”,’ she said.

Dr William Schaffner, a liaison representative for the National Foundation for Infectious Diseases, warned many doctors were unaware of the treatments because they were approved at a time when there was an ‘avalanche’ of Covid news.

‘No one knows about Evusheld,’ he said. ‘I think it’s very sad.

‘There’s never been a mechanism that says “hear ye, hear ye, we have a new way to protect your immune-compromised patients against Covid, and here’s how you get it for your patients”.’

There have also been problems distributing Merck’s Lagevrio — the brand name for molnupiravir — which, like Paxlovid, is available for immunocompromised people within five days of them developing Covid symptoms.

It is taken as four capsules every 12 hours for five days, and is also free to Americans.

Clinical studies show Lagevrio reduces the risk of hospitalization and death by 30 percent among patients with at least one factor putting them at greater risk from Covid — such as being overweight or having an underlying condition.

The U.S. is currently averaging about 39,400 Covid cases a day, up slightly from the 33,000 recorded a week ago.

But there are growing outbreaks in several states — such as New York — which may be being fueled by a new strain of Omicron.

It is thought U.S. case totals are also a serious undercounting of the current situation on the ground, as many people with Covid symptoms do not get tested.

Hospitalizations in the country are currently averaging about 1,400 a day which was barely a change from a week ago.

But some regions — including the city of Philadelphia and several universities — are already bringing back mask mandates fearing another surge in cases.