Product Review: Lucira Covid Test
Those free Covid tests you got from the government belong in the garbage. You should be using shiny new tech that’s literally a thousand times better
A recent post on OK Doomer covers the tragic tale of Bob Wachter’s broken neck. With the benefit of hindsight, I see a number of things Wachter could conceivably have done to avoid breaking his neck. In this post, I’ll drill down on only one of his regrettable fails. My bet is that if Wachter had simply used a better Covid test, he could have avoided traumatic brain injury.
On a Sunday afternoon, Wachter felt flu-like symptoms. He took a standard Covid home test, also known as a rapid antigen test (RAT), and it came back negative. So he popped two Tylenols and went to bed. He woke up Monday morning feeling sick as a dog and bathed in sweat - so he understandably chose to hop in the shower. It turns out he was in such a fragile state of health the heat of the shower made him faint and he hit his head so hard on the way down it gashed open his face, gave him a brain bleed, and fractured his third cervical vertebra1. At the hospital, a PCR test revealed he had Covid. He immediately went on Paxlovid because - as everybody knows - Paxlovid works better the earlier you take it. It makes sense to close the barn door before the horse has left the stable.
When home RATs first came out, I was overjoyed - even though we’ve been aware from the start that RATs are nowhere near as sensitive as PCR tests. Although I know of a handful of cases where friends infected each other because a RAT failed to detect an asymptomatic infection, the more typical experience was that RATs helped friends realize they had Covid so they could avoid infecting others and seek early treatment. A not-so-sensitive RAT you can run without supervision in under 15 minutes offers major advantages over a PCR test where you have to traipse across town to see a health care provider and wait days for results.
The important game-changer came when a second generation of home “molecular tests” were finally, after a lot of paternalistic foot-dragging, approved by the FDA. The newer “LAMP” tests are a miracle of modern molecular wizardry - they’re just as fast as RATs, but vastly more sensitive. The new molecular tests are essentially as good as PCR tests. I know some of the scientists who helped develop the second-generation molecular tests, and I confess my initial snap-judgment at the start of the pandemic was that my friends were probably tilting at windmills. I found it hard to imagine all the fancy enzymes working well on something other than purified virus RNA (à la familiar PCR tests). I was wrong. My friends were right. The new molecular tests work great on snot and spit.
My favorite rapid molecular test is a brand called Lucira. Although the maneuver isn’t covered by official FDA authorizations, I’ve found that it’s feasible to put up to 10 swabs into a single Lucira test. At a recent family holiday gathering, we decided to be extra careful because one of my cousins was being treated for brain cancer. A group Lucira test came up positive. It turned out that a seemingly healthy family member was harboring an asymptomatic Covid infection. Crisis averted.
Circling back to Bob Wachter, we can easily imagine a counterfactual scenario where he used Lucira instead of a crappy false-negative-addled RAT. Another advantage of Lucira is that you can easily mix together separate nose and throat swabs in one test. Throat swabs usually turn up positive earlier in the infection than nasal swabs. It seems like a safe bet that Wachter’s Lucira nose and/or throat swab would have turned up positive on Sunday, and he would have known he should pop a Paxlovid instead of a Tylenol before going to bed. Taking Paxlovid on Sunday would have reduced Wachter’s risk of waking up Monday in such bad shape that he nearly bashed his brains out on a bathroom garbage can. Live and learn. Or, in this case, nearly die and don’t learn.
It was good that the government helped make RATs widely available when they were the only home option. But the moment the superior LAMP tests became available, we should have stopped handing out crummy RATs and started distributing - or at least recommending - the vastly superior molecular tests. Instead, we got into a scenario where I had to go scour my parents’ house looking for the free orange-box government RATs they had salted away so I could aggressively replace the obsolete kits with Luciras. The grip of sunk cost fallacy can be strong - even in cases where the cost in question is “free,” and the consequences of “frugally” using up the last of the obsolete kits could literally have been a neck-breaking faceplant.
It’s frustrating that experts like Wachter remain blithely ignorant of Lucira and other new molecular tests. The lack of clear public health messaging - together with the fact that the government continues to put its thumb on the commercial scale by handing out free RATs - has produced a disastrous market failure. Instead of superior LAMP products profitably winning out in a competitive marketplace, Lucira recently declared bankruptcy - and the kits are currently hard to find. Fiasco.
Update 1: After a few months of interrupted supply, Lucira kits are widely available again: https://a.co/d/gVA23wO
Update 2: A newer molecular test called Metrix recently came on the market https://a.co/d/eUunfRv. Although Metrix is about half the cost of Lucira, my family’s casual testing experiments suggest Metrix is much less sensitive than Lucira. If your experience with Metrix is different, please post a comment about it!
Obligatory disclaimer: I’m not a medical doctor. This article is a product review recounting my personal experience hacking a testing device. Use (or don’t use) my advice at your own risk.