A surge of new coronavirus antibody tests, some of them used in studies that appear to show a far greater rate of infection and recovery than we’d imagined, has set the world to dreaming.


Maybe so many people have been infected that the actual fatality rate from COVID-19 is too low to justify closing down so much of our day-to-day lives. Or maybe a positive antibody test could be used as a kind of “passport” to work and normal life, since that person theoretically couldn’t be sickened and couldn’t pass the virus on to others. Or better yet, maybe we are nearing herd immunity, in which high numbers of immune people keep the disease from sickening the population at large, enabling the public to be set free from their homes.


For now, sorry to say, those are just dreams.


Unlike the diagnostic “PCR” tests that measure whether someone has contracted COVID-19, antibody tests look at a body’s immune system for evidence that an individual has been exposed to and defeated the disease.


The nation is awash in more than 120 antibody tests for the novel coronavirus that were approved by the Food and Drug Administration without requiring the usual verification of accuracy. The agency was attempting to get the tests out quickly and avoid a repeat of the unconscionable delays in producing the PCR tests, which remain in too short supply.


But having plenty of tests won’t help if they’re inaccurate, and some of the antibody tests have unacceptably high rates of false positives. Such mistakes give people the dangerous belief that they’re safe from the disease and an even more dangerous belief that they can’t infect others. Those who show up at a medical office for antibody testing are unlikely to know exactly which test they’re being given and what its accuracy rate is.


Even with very accurate tests, the presence of antibodies doesn’t necessarily mean immunity; too little is known about the resistance that antibodies provide to reinfection. If that immunity exists, it’s also unclear how long it will last.


Studies that purportedly showed that vastly more people have been infected have come under criticisms for alleged shortcomings in their methodology. But even if many people had been infected, and even if they had immunity as a result, and even if that immunity could be counted on to last at least several months — we’re piling up the “ifs” here — we’d still be woefully short of what’s needed for herd immunity.


And even if COVID-19 has a significantly lower fatality rate than originally thought, that doesn’t mean it couldn’t kill a lot of people. Given that the virus is easily spread through casual contact and there are no known treatments, if there is no broad-based social distancing, a fatality rate of less than 1% could still exact a horrendous toll.


The FDA needs to figure out which tests are worthy of approval and which aren’t, and then allow only the former on the market. More robust studies using those tests are needed to give us a better idea how widespread the infections have been, and those are coming.


And unfortunately, we’ll have to wait to find out more about the role of antibodies in preventing future infection, and, we hope, to obtain an effective vaccine from the more than 80 under development. That’s our best chance at herd immunity. Yes, science and government need to move quickly against a fast-moving virus, but speed isn’t a substitute for reliable information.


Los Angeles Times