Plasma is being studied as a way to fight off the virus
The possible therapy is based on a medical concept called Âpassive immunity. People who recover from an infection developÂ antibodiesÂ that circulate in the blood and can neutralize the pathogen. Infusions of plasma ÃÂ the clear liquid that remains when blood cells are removed Â may increase people disease-fighting response to the virus, giving their immune systems an important boost. The approach has been used against polio, measles, mumps and flu.
The recovered people could haveÃÂ in their bloodÂ something that could be very useful, said Arturo Casadevall, chair of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health. The history is this has been used in 120 years in medicine, and its well-known.Â
Casadevall is hopeful the treatment, called Âconvalescent plasma, could provide short-term relief to a medical system that faces a surge of patients, with no approved drugs or vaccines. But he and colleagues face regulatory, logistical and scientific challenges to set up a process that will ultimately be limited in how many people it can treat. Researchers must collect blood plasma from people after theyÂve recovered, then test it to determine if it is likely to be potent against the disease and deliver it to patients.
New York Gov. Andrew M. Cuomo (D)announcedÂ his state would begin trying the treatment in patients stricken with covid-19, the disease caused by the coronavirus. The Food and Drug AdministrationÂ announced TuesdayÂ it was helping facilitate access to the experimental treatment, while underscoring the need to establish safety and effectiveness. Mount Sinai Health System in New YorkÂ announcedÂ this week that it plans to begin transfers of antibody-rich plasma from recovered patients to people who are severely ill.
We get really hung up on always trying the newest, latest, greatest thing. And sometimes the classics are good, too, and they tend to be ignored, said Jeffrey P. Henderson, an infectious disease specialist at Washington University in St. Louis, who is working on the project.
First, experts must develop tests to measure the levels of antibodies, and then use those to identify donors whose plasma is rich in antibodies that could help others battle the illness. Then, they have to deliver the plasma to patients Â most likely in clinical trials designed to measure whether it works. The plasma must be safe and disease-free, not only from other blood-borne pathogens but also from the novelÂ coronavirus.
Plasma could be used to treat people who are sick and to prevent illness in health-care workers, Casadevall said, especially those at greatest risk for developing the illness because of repeated exposure
Access to the therapy is likely to vary. Many hospitals are racing to set up clinical trials that would be open to patients who meet specific criteria. The FDA has also created a track for Âemergency useÂ a way for people with serious or immediately life-threatening illness to gain access to the treatment. But many logistical questions need to be solved, including the question of who will pay for the experimental treatment.
On Friday,ÃÂ Bloomberg PhilanthropiesÂ and the state of Maryland announced they would jointly provide $4 million to support the effort.
ÃÂÃÂFor specific services, I am charging my endowment funds. The resources will catch up. If they donÂt catch up, that is life,Â Joyner said.
But the research into plasma is only one part of a broader effort to learn from peopleÂs natural immune response to unlock secrets to treatment. In the longer term, Marasco and other researchers plan to develop drugs based on coronavirus-fighting antibodies. Marasco has a library of 27 billion antibodies from 57 donors that he plans to screen, looking for ones that are active against the new coronavirus.
ÂItÂs hard to tell in this exceptional time,Â Nussenzweig said. ÂNormally, this is something that would take a year and a half. I donÂt know exactly how much it can be accelerated.Â The convalescent plasma approach is appealing because it could provide a shorter-term option than an antibody therapy, which is also being pursued by drug companies. But even those who are working to make the treatment possible acknowledge it is just a bridge to a better, and more broadly accessible, solution.
To give the treatment the best chance of succeeding, the researchers want to make sure they provide patients plasma that contains lots of antibodies Â and design trials that can rigorously demonstrate whether it is working.
ÂI did have an adverse reaction Â my heart rate dropped to 40, and they had to stop the transfusion briefly before resuming it, Mukpo said in an email. ÂIt was a very unpleasant experience, but I did feel better the next day. Its hard to say whether that was because of the transfusion or just my body finally getting over the hump” Â Courtesy Washington Post