Pfizer researchers looking for a drug to treat SARS found clues that gave the company a head start in its quest for a pill to treat COVID-19, including the omicron variant.

The drug, known as molnupiravir, has shown promise in treating the disease. The agreement to license its production could help millions of people in the developing world gain access to it.

The medicines from Eli Lilly and Regeneron are infused, a process that can take two hours or longer, including observation for side effects. Staffing is as big an issue as the supply of the drugs.

Eli Lilly's monoclonal antibody will be available to people 65 or older or those with underlying health conditions. Supplies will be short, and allocating the medicine will be a challenge.

To boost the supply of Regeneron's antibody therapy for COVID-19, the federal government entered into a $450 million supply contract. Details of the deal show some safeguards are missing.

The federal government plans to distribute 300,000 doses of the drug at no cost, but that doesn't mean treatment will be free. Intravenous infusion charges can run more than $1,000.

Medical researchers have high hopes that the kind of treatment the president received could end up being an important element in the fight against the pandemic. But clinical trials continue.

President Trump announced on Sunday that the FDA granted emergency use authorization to treat COVID-19 patients with plasma from people who have recovered from the virus, based on "promising" results.