Plasma taken from recovered patients of COVID-19 are being used by researchers to try and cure the affected lot. This hypothesis is simple. The blood of people who have recovered from an infection contains antibodies. Antibodies are molecules that have learned to recognize and fight the pathogens, such as viruses, that have caused disease. Unlike with vaccines, whose development takes time, or experimental medication, which needs to go through several different stages of testing before it can obtain formal approval, this approach allows doctors to use what is already there — the blood of those who have recovered from the illness — to treat hospitalized patients. But while vaccines also operate on the premise of stimulating a person’s immune system to block or kill the virus, they do not use “ready-made” antibodies, and testing them for safety and efficacy could take a year or more. Doctors could use this therapy alongside other options as they gradually become available. “Convalescent plasma provides something that can be used today with standard knowledge and standard procedures. But we do hope that better options will be available in the future,” said Dr. Arturo Casadevall, chair of the Molecular Microbiology & Immunology Department at Johns Hopkins Bloomberg School of Public Health.