At least five US teams have cloned antibodies to Covid-19, paving the way for cutting-edge treatments that could be what one researcher calls “an immunity bridge” before a vaccine comes along.

The treatment is monoclonal antibody therapy, and the antibodies come from people who have recovered from the novel coronavirus. Researchers then take the blood, select the most potent antibodies, and make them into a drug. One company, Regeneron Pharmaceuticals, hopes to have a treatment available to patients as early as the end of the summer.

“I think monoclonal antibody therapy has enormous promise as the next big thing for Covid-19,” said Dr. Peter Hotez, a vaccine specialist at Baylor University School of Medicine who is not involved in the research.

Monoclonal antibody therapy is a modern take on convalescent plasma, where someone who has recovered from coronavirus donates blood to someone who is currently ill.
Even if convalescent plasma is effective — it’s still being studied — it has two shortcomings.
First, one person can only give so much blood. Second, the donor might not have enough strong antibodies for the blood donation to be effective.

To develop a monoclonal antibody treatment, researchers cull through thousands of antibodies to find the best ones, and then clone them potentially in unlimited amounts.
Many other illnesses are treated with monoclonal antibodies, such as various forms of cancer, HIV, asthma, lupus, multiple sclerosis and various forms of cancer, but of course there’s no guarantee it could work for Covid-19.

“One of the things about the search is it’s a little bit like finding a needle in a haystack. We’re all searching for the magical antibody that’s a silver bullet,” said Dr. James Crowe, who’s leading the Covid-19 monoclonal antibody effort at Vanderbilt University Medical Center.

Regeneron is hoping to start clinical trials for an antibody treatment for coronavirus in humans as soon as next month, and if everything goes right, perhaps have a treatment ready for widespread distribution by the end of the summer.
“We generated thousands of [antibodies] and then selected the most powerful and potent ones to grow up into an antibody cocktail,” said company president Dr. George Yancopoulos.

Like any treatment under development, it might not pan out. But if it does, it could treat coronavirus and possibly also prevent infection for a period of time.
A vaccine would likely offer longer lasting immunity, but that would likely take longer to develop, with the earliest estimates set at January.

“I think antibodies will be finished first, and will be the bridge toward longer immunity, which will be conferred by vaccines,” said Crowe, director of the Vanderbilt Vaccine Center at Vanderbilt University Medical Center.