Dr. Scott Gottlieb told CNBC on Friday that antibody drugs are likely to be important treatments for the coronavirus, but he cautioned against considering them a panacea for the nation’s Covid-19 outbreak.

The former U.S. Food and Drug Administration commissioner said the lack of supply means not every person who becomes diagnosed with the coronavirus will be able to receive an antibody treatment — should the FDA grant emergency use authorization to the two companies that recently applied. 

“I think these drugs will make a meaningful difference for people who are the highest risk of having a bad outcome,” Gottlieb said on “Closing Bell.” ”But this is not going to end the epidemic. This is not going to be widely available to everyone,” he added. 

Priority would probably be given to Covid-19 patients who are over the age of 65, given they are more likely to become severely ill or die, according to Gottlieb. People who have significant underlying medical conditions also would be higher on the list of patients to receive an antibody treatment, he said. 

“We’re not going to have this available in the kind of volumes where you’d want to give it to everyone who is at risk and maybe even as a prophylaxis for people who are at high risk of contracting the infection like people in nursing homes, front-line health-care providers, front-line workers,” he said. 

This week, Regeneron Pharmaceuticals and Eli Lilly both announced they had submitted emergency use applications to the FDA for their monoclonal antibody treatments for the virus. Both companies have released early data showing the antibody drugs could be promising treatments for Covid-19.

The potential treatments have come into focus in recent days after President Donald Trump received Regeneron’s antibody cocktail after he became sick with Covid-19.  

Trump, who received the treatment on a compassionate use basis, has gone on to tout the experimental drug as “a cure” for Covid-19. However, the president received other treatments for the coronavirus, such as Gilead Sciences‘ antiviral remdesivir, and it is difficult to determine the effectiveness of a single drug outside of a randomized clinical trial. 

Antivirals such as remdesivir try to stop the virus from replicating, whereas antibody drugs attach to the existing virus in the body and attempt to neutralize it. 

Although he cautioned the datasets are still limited, Gottlieb stressed he believes the antibody drugs are likely to provide a benefit for Covid-19 patients. But, he said, the U.S. missed an opportunity to ramp up manufacturing in the spring to ensure there are widespread doses available as the drugs come onto the market. 

Antibody drugs are difficult to manufacture, and both Regeneron and Eli Lilly teamed up with rival companies to help produce them. In August, Tarrytown, New York-based Regeneron announced an agreement with Swiss drugmaker Roche to make and distribute its antibody cocktail. 

Indianapolis-based Eli Lilly signed a similar manufacturing agreement for its potential therapy with Amgen, a California biotech firm. 

The companies “worked hard” to get more production capacity online, said Gottlieb, who led the FDA under Trump from May 2017 to April 2019. “But there really wasn’t a national, coordinated strategy to free up manufacturing capacity to be able to produce these at the mass scale that, if we had them at that scale right now, we could effectively use them as a vaccine.”

“Remember, these could be not only used potentially to treat people who are infected and prevent them from getting sick, but you could potentially give people a monthly injection of these drugs and prevent them from ever getting infected,” he added. “That’s how [antibody drugs] were used very successfully in the setting of Ebola.” 

Regeneron said this week that it currently has enough doses of its antibody cocktail for 50,000 patients. It expects to have “doses available for 300,000 patients in total within the next few months,” according to a press release. In early February, Regeneron received the U.S. government’s first batch of funding to develop a Covid-19 treatment. 

Eli Lilly indicated Wednesday that it could supply 100,000 doses of its single antibody treatment in October and up to 1 million doses during the fourth quarter of 2020. The company also has a combination antibody treatment and 50,000 doses of it could be available in the fourth quarter. However, Eli Lilly hasn’t yet applied for emergency use authorization for the combination therapy. 

Given the case count in the U.S., Gottlieb said the current supply of antibody treatments would be insufficient. “You’re going to burn through the supply very quickly, even if infection rates stay at the current levels, which I think that they’ll probably continue to rise,” he said. 

Gottlieb said the government should still consider orchestrating a program to help manufacture more antibody therapies, even though there are high hopes a vaccine may also be ready in the coming months. 

“We should be taking steps right now … to try to make sure we have that supply available in 2021 so we’re not constantly struggling to try to get adequate supply of these drugs, if in fact they’re demonstrated to be safe and effective,” Gottlieb said. “And I think all the early data is encouraging.”