With a vaccine against a coronavirus still months away, companies are rushing to test what the next best thing might be: drugs that deliver antibodies to fight off the virus, without training the immune system to make them.
Antibodies are proteins that the body makes when an infection occurs; they attach to a virus and help eliminate it. Vaccines work by tricking the body into thinking there is an infection so that it makes antibodies and remembers how to do that when the real bug appears.
But it can take a month or two after vaccination or infection for the most effective antibodies to form. The experimental drugs speed up that process by giving concentrated versions of specific ones that work best against the coronavirus in lab and animal tests.
“A vaccine takes time to work, to force the development of antibodies. But if you give an antibody, you get immediate protection, “said Dr. Myron Cohen, University of North Carolina virologist.” If we can generate them in large concentrations, in large fats in an anti-antibody plant … we can The immune system kind of passes. “
These drugs are believed to last a month or more and could rapidly, temporarily grant immunity to people at high risk of infection, such as health workers and family members of someone with COVID-19. If proven effective and if a vaccine does not materialize or protect as hoped, the drugs could eventually be considered for wider use, perhaps for teachers or other groups.
They are also tested as treatments, to help the immune system and prevent serious symptoms like death.
“The hope is to target people who are in the first week of their illness and that we can treat them with the antibody and prevent them from getting sick,” said Dr. Marshall Lyon, an infectious disease specialist taking one such drug test at Emory University in Atlanta.
Having such a tool “would be a very important thing in our fight against COVID,” Cohen said.
Vaccines are seen as a key to controlling the virus, which has confirmed that more than 20 million people worldwide have infected and killed more than 738,000. Several companies are racing to develop faxes, but the results of the big definitive tests needed to evaluate them are months away.
The antibody drugs are “very promising” and, in contrast, could “fairly quickly,” said Dr. Janet Woodcock, an official with the U.S. Food and Drug Administration who is leading the government’s efforts to accelerate COVID-19 therapies. Key research is underway and some answers should come by early fall.
One company, Eli Lilly, has already begun developing its anti-antibody drug, betting that research studies will now yield positive results.
“Our goal is to get something out of it as soon as possible” and to prepare hundreds of thousands of doses for the fall, said Lilly’s chief scientific officer, Dr. Daniel Skovronsky.
Another company that developed an antibody cocktail against Ebola – Regeneron Pharmaceuticals Inc. – now testing one for coronavirus.
“The success of our Ebola program gives us some confidence that we can potentially do this again,” said Christos Kyratsous, a Regeneron microbiologist who helped lead that work.
Regeneron’s drug uses two antibodies to improve the chances that the drug will work, even as the virus evolves to evade action by one.
Lilly is testing two different drugs with one antibody – one with the Canadian company AbCellera and another with a Chinese company, Junshi Biosciences. In July, Junshi said there were no safety concerns among 40 healthy people who attended and that larger studies were underway.
Others working on antibody drugs include Amgen and Adaptive Biotechnology. The Singapore biotech company Tychan Pte Ltd. is also testing an antibody drug and has similar products in development for Zika virus and yellow fever.
“I am cautiously optimistic” about the drugs, said the expert on nature’s top infectious diseases, Dr. Anthony Fauci. “I am guided by the experience we had with Ebola,” where the drugs proved effective.
What could go wrong?
– The antibodies may not reach all the places in the body where they need to act, such as deep in the lungs. All antibody drugs are given via an IV and must make their way through the bloodstream to where they are needed.
– The virus can mutate to prevent the antibody – the reason Regeneron tests a combo with two antibodies that bind to the virus in different places to help prevent it from escaping.
Skovronsky said Lilly sat on one antibody because the production capacity would essentially be cut in half to make two, and “you will have fewer doses.” If a single antibody works, “we can treat twice as many people,” he said.
– The antibodies may not last long enough. If they disappear within a month, it is still OK for treatment, because COVID-19 disease normally resolves during that time. But for prevention, it may not be practical to report infections more often than every month or two.
A San Francisco-based company, Vir Biotechnology Inc., says it has engineered antibodies to last longer than normal do to prevent this problem. GlaxoSmithKline has invested $ 250 million in Vir to test them.
Giving a higher dose can also help. If half of the antibodies disappear after a month, “if you give twice as much, you’ll have two months of protection,” Lilly’s Skovronsky said.
– The big fear: Antibodies can do the opposite of what is hoped for and actually improve the virus’ ability to enter cells or stimulate the immune system in a way that makes people sick. It is a theoretical concern that has not been seen in tests so far, but large, definitive experiments are needed to prove safety.
“As far as we can tell, the antibodies are useful,” Lyon said.
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Marilynn Marchione can be followed on Twitter: @MMarchioneAP
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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.
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