At first, the beloved boomers in our lives had a hard time accepting the brutal reality of the coronavirus pandemic, despite being among those most at-risk for severe complications. Now that they’ve more or less adapted and are staying home, having their groceries delivered, canceling their cruises, and avoiding goddamn nonessential travel, the nation’s parents seemed to have moved on to another viral fallacy: the enduring hope of the antibody test.
Scientists have been discussing the importance of a serological test, or antibody test, for months, and for good reason. Earlier in the pandemic, researchers hypothesized that knowing who’s already had COVID-19 could indicate who’s immune to it, which could have been vital information for essential workers and those working on the frontlines in healthcare.
But scientists don’t yet know enough about this coronavirus to sign off on any such thing. That antibodies could signal immunity has been a particularly compelling artifact to wish upon for elected officials who are chomping at the bit to “reopen” their economies. Some have shifted focus to getting everyone antibody tests (even as testing rates for active infections remain abysmal), and are throwing around phrases like “immunity passport.” The World Health Organization has said that it’s still way too soon for antibody tests to be the marker of immunity, and an ability to resume normal life.For now, they remain something of a glimmering promise; they sound great but don’t offer much practical use, outside of maybe a little peace of mind (and even that’s questionable, at best). Here are the facts about why that is the case, framed as good talking points for the next time a boomer relative pesters you about getting an antibody test, and flying home (don’t fly home).
- Scientists don’t yet know how long “immunity” lasts.
The excitement about antibody tests seems mostly predicated on the idea that the presence of antibodies equals immunity. Though it seems like this pandemic has spanned years, COVID-19 is still a relatively new virus, and hasn’t been around long enough to establish how easily people can be reinfected, and we do not know yet with certainty that the presence of antibodies directly translates to any immunity. Reinfection within months or years is common with other human coronaviruses, and it’s still extremely unclear how COVID-19 operates in this respect
- Scientists also don’t know what level of antibodies confers immunity.
Even if a test could show antibodies are present, scientists don’t yet know what level of antibodies a person needs to be actually immune to this specific virus. “The ‘get out of jail free’ card we’re hoping for, it’s just not how it should be sold,” Gigi Gronvall, a senior scholar at the Johns Hopkins Center for Health Security and a co-author of a recent report on antibody testing, recently told the Atlantic.
- Early data suggests not that many people even have the antibodies.
Preliminary studies show far fewer people are testing positive for antibodies than scientists first expected. A pair of studies from the Bay Area and Los Angeles County show antibodies in less than 5 percent of the population, and that’s with methodological errors that likely led to overestimations. Even with full faith that positive antibodies equal lifelong immunity, these figures are still far off from the estimated 70 percent that scientists say establishes herd immunity.
Because of this, even if the fantasy that people who test positive for antibodies can just return to normal life were otherwise feasible (i.e., if a positive test meant the person had definitely been infected before, is substantively immune, and could no longer carry the virus), not remotely enough people have come into contact with the virus for that to be the case.
- Even the “best” antibody tests can still return false positives.
As VICE previously reported, “countless teams of scientists around the world are developing serological tests to detect antibodies related to COVID-19.” The UK recently bought 3.5 million finger-prick tests from China that did not work.
Even with a high confidence level in a particular test, large scale testing is still going to return a lot of false positives. “If the prevalence of COVID-19 is quite low in the population—say, 5 percent—and a test can identify people who are truly negative with 95 percent reliability, half of the ‘positives’ it returns will be false positives,” Zhang reported in the Atlantic. “In other words, half of the people the test says have antibodies wouldn’t actually have them.”
- The most important testing remains the test for active coronavirus infections, and contact tracing, a process that the U.S. hasn’t yet implemented.
Any elected official (or friend, or boomer relative) touting the promise of antibody tests as the key to reopening is putting the cart way before the horse. What matters most now remains what has mattered most throughout the pandemic: More testing capacity for active infections, and encouraging everyone who can do so to stay at home and minimize their movement and interaction with other people.
There are also more opportunities for managing the virus spread that the U.S. hasn’t yet tried to implement. South Korea has also seen vast improvements in infection rates by using contact tracing, or a controversial practice that uses digital monitoring (CCTV, credit card transactions, and GPS phone tracking) to send text alerts to anyone who has come into contact with an infected person. Germany is working on implementing a less-intrusive version of this process.
All of this is subject to change, as the pandemic evolves and antibody tests are subject to further study, but for now, antibody tests are not the magic bullet that many politicians are desperately wishing they were.
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