It was early January and my friend in Melbourne had invited me over for coffee. But a surge in the omicron variant was driving Australia to a record number of daily cases, with hospitals overflowing. In that light, the unusual request made total sense: would I mind taking a rapid antigen test before coming inside.
And so I sat in the car, waiting for that little red line to appear before joining my friends.
At as little as $5 apiece, RATs have become the frontline tool for governments and institutions to quickly check whether a person may be infected with Covid-19. The process is simple: Stick the provided cotton swab up each nostril (and/or throat) until you meet resistance, twirl it a few times, and swirl the tip in a small tube of liquid before putting a few drops onto a test strip. Then wait around 15 minutes for the lines. One line (the control) means negative, two (control and test) means positive.
Although the process is much faster than reverse transcription polymerase chain reaction tests, the gold standard, and RATs for Covid-19 have been around for more than a year, it’s taken time for governments to accept them in full. Their reticence is understandable because RATs aren’t as sensitive as RT-PCR tests, meaning that a positive case may not always be picked up.
But that was a time when leaders had decided to shoot for Covid-zero — no infections would be tolerated — or accept a wider spread of the virus. Most of the world has since moved on. Today the question is one of balance between returning to normal and restricting movement in order to protect populations.
RATs now play an important part of the equation. RT-PCRs have around 98% sensitivity, which is close to ideal. By comparison, the best rapid tests pick up only 90% of cases in people with symptoms, and fewer than 50% for those without.
But that’s still good enough because, many believe, a rapid test is better than no test at all when it comes to sorting who may need to be isolated. It’s for this reason that authorities around the globe are deciding to offer tests, and even require they be performed. In Australia, for example, state governments recently decreed that school children get tested twice per week in order to attend class in person, with authorities footing the bill. The federal government, meanwhile, is promising to provide free tests to pensioners and other low-income citizens.
Ironically, like the US government a month ago, Australia’s leaders may be getting ahead of themselves, because slow action to procure supply means the country is running low on testing kits leading to queues at retailers and frustration among citizens as cases rise. A similar thing happened in the lead up to Christmas, when President Joe Biden pledged to send free testing to any household that asked, from a stockpile of up to 500 million kits. He’s since upped that commitment to one billion.
But supply will eventually catch up, as it did with masks and other personal protective equipment. When they’re in abundance we’ll likely see people test themselves voluntarily, even if just for peace of mind. That’s already starting to happen as party hosts and sports groups offer kits as a lure, or requirement, for attendance. In the dating world, people will expect to see a negative test strip before meeting up with a prospective partner, and refusal as an immediate disqualifier.
And just as people tout their vaxx status on social media, expect more Instagram pics of those little plastic kits. Remember to watch for that second line.
Bloomberg
