When President Donald Trump got sick with Covid-19 in October, he credited an antibody drug from Regeneron with making him feel better "immediately."
"I felt as good three days ago as I do now," he said in a video shot in front of the White House after he left Walter Reed National Military Medical Center, promising medicines from Regeneron and Eli Lilly would soon be available to the American public to help stop the terrible effects of Covid-19.
The concern, as these drugs were cleared through the FDA and made it to market last month, was that there wouldn't be enough supply. They're complicated to manufacture, and Regeneron said there were only enough doses for 80,000 Americans by the end of November. Lilly has 250,000 doses available.
An average of more than 200,000 Americans are currently getting diagnosed with Covid-19 every day, according to data compiled by Johns Hopkins University. Policymakers expected to need to ration the antibody drugs.
But a month into their distribution, the opposite problem has emerged: the drugs are not getting used.
"We have a surplus of these monoclonal antibodies right now," Health Secretary Alex Azar told CNBC's Shepard Smith Tuesday night. "What's happening is people are waiting too long to seek out the treatments."
Moncef Slaoui, chief scientific adviser to the U.S. government's Operation Warp Speed, told CNBC Tuesday that the federal government is distributing about 65,000 doses of the antibody drugs every week to states.
But, he said, only 5% to 20% of the doses are getting administered to patients.
"It should be used much more," Slaoui said in a telephone interview, noting the drugs -- which are indicated for patients at high risk for severe Covid-19 -- could cut down on hospitalizations by 50% to 70%.
The drugs are not simple to administer. For one thing, they're given by intravenous infusion, so patients must go to health centers where this can be done. But since they're likely contagious, existing IV facilities, like where patients receive chemotherapy, can't be used.
Another issue is that the drugs need to be given early in the course of the disease. The FDA's guidance for health-care providers says they should be administered as soon as possible after diagnosis, and within 10 days of symptom onset. It recommends against use of the drugs once patients are so sick they're hospitalized.
But many patients don't feel sick right away, so the idea of an IV-infused drug doesn't occur to them immediately after diagnosis, Slaoui and Azar suggested.
"If you are over 65 or at risk of serious complications or hospitalization due to co-morbidities, what have you, and you test positive, you need to seek out and get the Lilly or Regeneron monoclonal antibody," Azar said on the "News With Shepard Smith." "It can dramatically reduce the risk for us of hospitalizations at a time when hospitals are getting very crowded with people with Covid."
But it's a challenge for some health systems to set up the infrastructure to deliver these drugs. Some states are using 100% of their allocation, Slaoui said. Others, like in Georgia and Illinois, may not be using any, according to former FDA Commissioner Dr. Scott Gottlieb.
Georgia's public health department didn't immediately respond to questions about their antibody usage. A spokeswoman for Illinois' Department of Public Health said providers aren't yet required to report use of monoclonal antibodies, but that the U.S. Department of Health and Human Services will require hospitals to report the information starting Jan. 8.
"Trying to get in place the infusion centers that you need, it's not an easy task," Gottlieb told CNBC's Squawk Box Wednesday morning. "Some states like Maryland have set up special sites and done a really good job, and other states didn't plan for this."
He also said funding is an issue.
"States are resource-constrained on their own," Gottlieb noted. "There's probably more the federal government can do to be back-stopping the states."
Gottlieb also warned the stunted antibody rollout is a bad harbinger for the massive Covid-19 vaccine distribution campaign just beginning in the U.S.
"It might be challenging for the states to distribute the vaccines if they can't distribute the antibody drugs," Gottlieb said.
He noted the data behind the medicines suggest "the number needed to treat in terms of keeping one patient out of the hospital ... is 10." Lilly has said it will have 950,000 doses available by the end of January, Gottlieb cited the effects if 900,000 doses were used: "That means if all of the drugs got distributed, we could avoid 90,000 hospitalizations or emergency room visits. That would be substantial."
Lilly noted the IV administration of the antibody drugs "presents unique challenges to the healthcare system," and said it's working to address the challenges to ensure patients who need the drug can get it. The company is running a number of pilot programs through Operation Warp Speed, including one with CVS for in-home infusions, a company spokeswoman said.
Slaoui said Operation Warp Speed would provide help, but "I really think it's the various centers that would need to do it themselves mostly."
"If there is a need of help that can be consolidated at the level of the state, of course tell us what you need and we'll work that out," Slaoui said Tuesday. But he also noted that if some states can't figure out how to use the medicines, the federal government would direct the doses to the places that could.
"If there are places that don't use them," Slaoui said, "why send them?"
Disclosure: Scott Gottlieb is a CNBC contributor and is a member of the boards of Pfizer, genetic testing start-up Tempus and biotech company Illumina. Gottlieb also serves as co-chair of Norwegian Cruise Line Holdings′ and Royal Caribbean's "Healthy Sail Panel."