Rapid Tests, in Time for Fall Surge
Last week, the first rapid, inexpensive, coronavirus tests were finally approved for home use by the Food and Drug Administration. These self-administered tests, which don’t require a physician’s prescription, can be used by anyone to determine whether they are infectious, in order to prevent asymptomatic spread of SARS CoV-2. The news was welcomed in particular by assistant professor of epidemiology Michael J. Mina, an immunologist who has been pushing for regulatory approval of such tests since the middle of last year, because they can help control outbreaks—including all those caused by novel variants of the virus—and prevent lockdowns. Even now, as more and more Americans are vaccinated daily, Mina foresees an important role for these antigen tests in what he predicts will be a November surge in infections.
“We’re not going to have all the kids vaccinated” by the time seasonal transmission ramps up again in the fall, he points out. “I feel pretty confident that the surge is going to be a lot smaller than last year” because of the country’s massive vaccine rollout. “But my concern is that the most vulnerable in our communities will then have been vaccinated almost a year earlier. Unfortunately, the most vulnerable are the most elderly, and elderly people don't hold on to their immunological memory very well.”
Mina predicts that some older people who were vaccinated in January and February will no longer retain very strong immunological responses by this fall and winter. “In that case, ongoing spread, even just among kids, will lead to increased case counts,” he explains. “If those cases start to translate into deaths…I think that's going to make everyone very uneasy, and could cause a clamp down again on society.” Rapid tests, if they can be made widely available, could prevent much of the transmission Mina anticipates, and keep society functioning without lockdowns, especially if used to keep nursing homes and schools open and infection-free. The tests yield results in minutes on a paper strip resembling a pregnancy test, and show a positive result only during the five- to six-day window when a person is actually capable of transmitting the virus to others.
News of the test approvals came the same day that the National Institutes of Health and the Centers for Disease Control and Prevention announced massive experiments in North Carolina and Tennessee to evaluate the use of rapid antigen tests at scale. The experiments will help researchers determine whether such tests can eliminate or reduce spread of infection in urban settings—and may help shape a national testing strategy. Because the tests are principally a means of protecting the broader community (ranging from family members, to co-workers, to the general public) rather than oneself, Mina hopes the government will allocate funds toward paying for them: “Public health is not just about suppressing the virus and blocking transmission. Getting kids back to school is a huge part of community public health.”
Although last week’s twin announcements were cause for celebration, Mina remained concerned that the supply of these tests (BinaxNow, made by Abbott, and the QuickVue SARS Antigen Test, made by Quidel) will be limited. “We already know” that they are “going to be picked up and used for K-8 school openings” (such tests are already being used in this manner in Massachusetts, for example), “and businesses will want them, and individuals are going to want them at home.” He could not predict how manufacturers will allocate the supply, but scarcity will likely drive prices higher than he had hoped (to perhaps $10 a test for direct sales to consumers; governments have been paying $5 per test for packs of 40 for use in congregate settings like schools). “Now we need to get more companies [to] produce these tests,” he says, “so that people can actually access them.”