With a coronavirus vaccine still a few months off, companies are rushing to test what might be the next best thing: drugs that give antibodies to fight the virus right away, without having to train the immune system to do them.
Antibodies are proteins that the body makes when an infection occurs; they join a virus and help it to be eliminated. Vaccines work by tricking the body into thinking it has an infection, so it makes antibodies and reminds us how to do it if a real bug appears.
But it may take a month or two after vaccination or infection for the most effective antibodies to form. Abbreviation of experimental drugs it processes giving concentrated versions of specific ones that worked best against coronavirus in laboratory and animal tests.
“A vaccine takes time to work, to force the development of antibodies. But when you give an antibody, you get immediate protection, “said Dr. Myron Cohen, a virologist at the University of North Carolina.”; If we can generate them in large concentrations, in large jars in an antibody factory. .. we can do some sort of bypassing the immune system. “
These medications are believed to last for a month or more and can provide rapid, temporary immunity to people at high risk of infection, such as health care workers and family members of someone with COVID-19. If they prove effective and if a vaccine does not materialize or protect as hoped, the medication may eventually be considered for wider use, perhaps for teachers or other groups.
They are also being tested as treatments, to help the immune system and prevent severe symptoms or death.
“There is hope to target people who are in the first week of their illness and that we can treat them with antibodies and prevent them from getting sick,” said Dr. Marshall Lyon, an infectious disease specialist who helps test such a drug at Emory University in Atlanta.
Having such a tool “would be a really important thing in our fight against COVID,” Cohen said.
Vaccines are seen as a key to controlling the virus, which has been confirmed to have infected more than 20 million people worldwide and killed more than 738,000. Some companies are competing to develop vaccines, but the results of the large final tests needed to evaluate them are months away.
Antibody drugs are “very promising” and, conversely, may be available “very soon,” said Dr. Janet Woodcock, a U.S. Food and Drug Administration official who is leading government efforts to speed up COVID-19 therapies. Key studies are underway and some answers should come by early fall.
One company, Eli Lilly, has already started producing its own antibody drug, betting that now-developing studies will yield positive results.
“Our goal is to get something out of it as soon as possible,” and to have hundreds of thousands of doses ready by the fall, said Lilly’s chief scientific officer, Dr. Daniel Skovronsky.
Another company that developed a cocktail of anti-Ebola antibody drugs – Regeneron Pharmaceuticals Inc. – is now testing one for coronavirus.
“Success with our Ebola program gives us some confidence that we can do it again potentially,” said Christos Kyratsous, a Regeneron microbiologist who helped guide that work.
Regeneron drug uses two antibodies to increase the chances of the drug working even if the virus evolves to avoid the actions of one.
Lilly is testing two different drugs, with a single antibody – one with Canadian company AbCellera and another with Chinese company Junshi Biosciences. In July, Junshi said there were no safety concerns in the 40 healthy people who tried it and that larger studies were starting.
Others working on antibody drugs include Amgen and Adaptive Biotechnology. Singapore-based biotech company Tychan Pte Ltd is also testing an antibody drug and has similar products under development for Zika virus and yellow fever.
“I am a cautious optimist” about medicines, said the country’s top infectious disease expert, Dr. Anthony Fauci. “I’m saddened by the experience we had with Ebola,” when the medication proved effective.
What could go wrong?
Antibodies cannot reach all the places in the body where they need to act, such as deep in the lungs. All antibody drugs are given through an IV and must make their way into the bloodstream, wherever they are needed.
– The virus can change to avoid antibodies – the reason Regeneron is trying a combination of two antibodies that bind to the virus in different places to help prevent its survival.
Skovronsky said Lilly stuck to an antibody because production capacity would essentially be cut in half to make two, and “you will have fewer doses available”. If a single antibody works, “we can treat twice as many people,” he said.
– Antibodies may not last long enough. If they fade within a month, it is still good for treatment as COVID-19 disease usually resolves by that time. But for prevention, it may not be practical to give infusions more often than every month or two.
A San Francisco-based company, Vir Biotechnology Inc., says it has created antibodies to last longer than they usually do to avoid the problem. GlaxoSmithKline has invested $ 250 million in Vir to try them out.
Giving a higher dose can also help. If half the antibodies disappear after a month, “if you give twice as much, you will have two months of protection,” Lilly’s Skovronsky said.
– The great fear: Antibodies can do the opposite of what is hoped for and actually increase the virus’ ability to enter cells or stimulate the immune system in a way that makes people sicker. It is a theoretical concern that has not been seen so far in testing, but large, definitive experiments are needed to prove safety.
“As best we can say, antibodies are beneficial,” Lyon said.
Marilynn Marchione can be followed on Twitter: @MMarchioneAP
The Associated Press Department of Health and Science receives support from the Department of Science Education of the Howard Hughes Medical Institute. AP is solely responsible for all content.