Convalescent plasma therapy has given doctors hope that an effective treatment for the coronavirus is already here, even if the evidence of its successes is anecdotal.

“Whether it is effective as a treatment, I can give you anecdotal experience,” said Dr. Sohail Rao, executive vice president of the DHR Health system in Texas. “It is a very safe procedure, and it is also very effective because we have seen patients who we were able to get them off the ventilator fairly quickly.”