Companies are rushing to test what may be the next best thing to a coronavirus vaccine: antibody drugs that fight the virus right away, without having to train the immune system to do the job. Antibodies are proteins the body makes when an infection occurs. They attach to a virus and help it be eliminated. The experimental drugs are concentrated versions of antibodies that worked best against the coronavirus in lab an animal tests. They’re being tested to treat COVID-19 and to prevent infection. Results of key studies are expected by fall. If they work, they could be approved before a vaccine.