In June 1981, the rapid-response newsletter of the Center for Disease Control, the Mortality and Morbidity Weekly Report, published news of an unusual pneumonia in otherwise healthy young men in Los Angeles. It would take four years from those first recorded cases of AIDS to the first FDA-approved test for HIV, and over a decade before the first rapid test. Given this history, the idea that we could have a point-of-care rapid test after mere months of a new pathogen’s emergence would seem hopelessly optimistic.
Yet that is what the first-of-its-kind alliance between the U.S. biotechnology industry and the federal government has delivered. Just four months after the emergence of Covid-19, a dizzying array of tests is available to patients, physicians, and researchers. The initial tests, dependent on identifying the viral genome, have now been supplanted by much faster, much less expensive antibody tests. Unlike genomic tests, which require laboratory equipment and take several hours to complete, the new antibody-based tests are portable, and some don’t require any special materials other than saline. The antibody tests may answer questions not only about a patient’s current state but also about whether he has been exposed in the past by measuring antibodies that the immune system creates in response to the coronavirus. Finally, just today, the FDA announced that it is granting authorization for the first Covid-19 test that can be taken at home, affording an opportunity for many people in at-risk groups who have forgone testing up to now. By all measures, the emergency regime set up by the FDA has opened the floodgates of innovation on one of the most vexing problems of responding to a viral outbreak, and with great success.
Unlike bacteria, which can be cultured conveniently in a petri dish, a virus is not easy to detect. The most reliable method uses a technique called polymerase chain reaction (PCR) to amplify the genomic material. But for this to be possible, at least part of the viral genome must be known. It wasn’t until the early days of 2020 that the first sequence of the coronavirus causing Covid-19 was published.
PCR testing is time-consuming, expensive, and requires specialized equipment and expertise. While many university labs have both the personnel and gear to perform small-scale testing, the throughput of PCR diagnostics for identifying viral infections has always been limited. Perhaps the most frequent indication for viral PCR diagnosis—HIV testing and viral-load quantitation—accounted for only 3.13 million tests per year in 2017. By comparison, coronavirus testing exceeded this number by April 17.
For sustainable, large-scale testing and sentinel surveillance—the periodic testing of vulnerable populations to act as bellwethers for resurgence—antibody tests are required. These tests can often be transported easily, either administered in the field or at bedside, and the results returned in as little as five minutes. More important, some antibody-based tests require no ancillary equipment. They can yield valuable information on whether the patient has ever been exposed to the virus.
It often takes years to create a viable antibody test as accurate as PCR-based testing. But in less than six weeks, biotech companies—approached by the U.S. government through the White House-created public-private partnership—have already seen their efforts bear fruit. This is a tribute to the incredible creative potential of the biotech sector, but it also shows the power of free enterprise, unshackled by government bureaucracy. It took more than America’s best scientists to rise to the occasion: it took a regulatory regime to let them do so. The FDA—long derided by the biotech industry for its tedious and costly approval procedures, out of proportion with what’s necessary to protect public health—has stepped up its game in this time of need. If any good is to come out of the loss and heartbreak of this pandemic, we can hope that this newfound flexibility by America’s pharmaceutical and biotechnology regulator will be part of it.