Researchers and drug companies around the world are testing the use of antibody therapies to treat and prevent Covid-19—but while some of the therapies have shown promise, experts say the therapies might not be available for use until next year. Here's what you need to know about the potential treatments.
What are antibody therapies?
Antibody therapies are created using antibodies that were naturally generated by either a human or animal that was infected with a given disease or virus. For Covid-19 antibody therapies, the treatments rely on isolated antibodies to neutralize the new coronavirus, known as SARS-CoV-2, which causes Covid-19.
Researchers have so far considered convalescent plasma treatments, which are made from the plasma of people who were recently infected with the virus and transfused into Covid-19 patients, as well as other treatments developed from the blood of newly recovered patients as potential antibody treatments for Covid-19.
Researchers have also started developing monoclonal antibodies, which are antibodies that can be isolated and manufactured in larger quantities via artificial reproduction, for the new coronavirus. According to Reuters, these types of antibody therapies can be easier to scale, because unlike convalescent plasma, monoclonal antibodies do not require a "steady supply of antibody-rich blood."
Some scientists are considering using the monoclonal antibodies for a prophylactic treatment that potentially could prevent infection from the new coronavirus before it is contracted, Scientific American reports.
Who is developing the therapies?
Several organizations are developing these potential therapies.
For instance, Regeneron Pharmaceuticals started developing Covid-19 antibodies in January, when the disease's genetic sequence became available. Researchers culled the antibodies from genetically modified mice that carry human genes, as well as people, to create an "antibody cocktail," Scientific American reports. Christos Kyratsous, VP of research on infectious diseases and viral vector technologies at Regeneron, said the cocktail could enter clinical trials in June, with the goal of having doses of its preventative monoclonal antibody treatments ready for use by later this summer or fall, according to Scientific American.
Separately, Vanderbilt University researchers have collected antibodies from about a dozen people who've recovered from Covid-19 and found about 40 antibodies that have the potential to neutralize the novel coronavirus, according to Robert Carnahan, associate director of the Vanderbilt Vaccine Center. The researchers are working with Cambridge University and AstraZeneca to develop potential therapies, some of which could enter clinical trials this summer, Carnahan said.
AstraZeneca is also working on a potential treatment combining two antibodies, which can "reduce the chance of resistance developing to one antibody," according to Pascal Soriot, the drugmaker's CEO.
Eli Lilly is developing different antibody treatments, including a monoclonal treatment, that have already started early testing in humans.
Meanwhile, the CoVIg-19 Plasma Alliance is using convalescent plasma to develop a standardized dose of antibodies that could be used on patients with different blood types. GlaxoSmithKline and AbbVie are also working to develop potential antibody treatments for Covid-19, according to Reuters.
When will the therapies be ready?
Studies suggest antibody therapies could be an effective way to treat Covid-19, but health experts say it will be a while before the treatments can be deployed.
Jill Horowitz, executive director of strategic operations at Rockefeller University's Laboratory of Molecular Immunology, said manufacturers may not have the existing capacity to produce antibody therapies. "Every factory that gets built has a reason. And you can bet that all those factories are committed to [existing] drugs that we need," Horowitz said.
Antibodies are also expensive, especially since they often are administered intravenously—a fact that could make them difficult to deliver on a larger scale, especially in lower-income countries, according to Arthur Reingold, an epidemiologist and biostatistician at the University of California-Berkeley.
The type of antibody treatment also determines when the treatments will be available. For instance, clinical trials for therapeutic treatments are usually faster than trials for prophylactic treatments, according to Horowitz. And since "therapy is a dire need right now," FDA is likely to approve treatments for Covid-19 faster than preventives for the disease—although approvals for antibody treatments are likely at least six months away, as well, Horowitz said.
So while antibody therapies may eventually help treat Covid-19, health experts "should be careful about how they communicate and basically create hope in the population," according to Florian Krammer, a microbiologist and infectious disease expert at the Icahn School of Medicine at Mount Sinai. "I think it's very dangerous to say, 'Within [months], we will have [an] antibody therapeutic that works, and everybody will get it.' That's unrealistic" (Erman, Reuters, 6/19; Kramer, Scientific American, 5/29; The Guardian, 6/7).