As we stare down September, COVID cases (and hospitalizations) are up everywhere across the country, due to a troubling new variant called Eris. In other words: It’s time to get reacquainted with COVID testing. While you may be used to thinking of COVID tests as interchangeable, there’s a big difference between the standard at-home test and a PCR. Almost four years in, it’s important to understand why PCR tests, which are now harder to find, are the ones you want when accurate testing is important.
The difference between a PCR and a Rapid Antigen Test
When at-home COVID tests became available, they were a powerful tool to help people know they were positive so they could isolate themselves from others. These at-home tests are lateral flow tests, also known as rapid antigen tests (RATs). They measure for proteins on the outside of SARS-C0V-2, but they have a major flaw: They can only detect active virus. If you’re asymptomatic or don’t have a high viral load yet, the RAT may show negative results, while you have an active and contagious infection.
This is why, if you already have symptoms, you may need to test a number of times to confirm you have COVID. Rapid tests are fairly reliable when they come up positive, but a negative doesn’t mean you’re COVID-free. When you first get sick, you may go a number of days (as many as five) without enough virus to set off a positive RAT test, but still be infected.
A PCR, also known as a NAAT or molecular test, measures RNA and can detect even small amounts of the virus. This is why it has always been considered the “gold standard” of COVID testing. These tests are generally considered accurate starting 1-3 days before you experience symptoms.
Why we still need COVID testing
While the likelihood you will die of COVID has gone down dramatically due to vaccines, medical interventions, and natural immunity from infection, the news has not done a great job talking about long COVID. As people get infected two, three, four, and more times, they are playing against the odds. It’s estimated that one in 10—or even as many as one in five—infections leads to long COVID, and to explain how much it’s not “just the flu,” COVID was reclassified as a vascular illness. That means it affects the blood vessels in your body, which go everywhere. Thinking of COVID as a vascular illness helps explain why long COVID is everything from extreme fatigue to migraines to COVID toe, loss of smell and taste, and neurological and cardiovascular conditions.
Through a fascinating irony, the only intervention we have left is an anti-viral called Paxlovid that you can only take within five days of symptoms, and for that, you need a positive test. An anti-viral knocks down your viral load, one of the things we think helps prevent long COVID.
It’s surprising how many people ignore Paxlovid, thinking it’s for extreme cases of COVID. You qualify to take Paxlovid if you are over 50, unvaccinated, or not up to date on vaccinations, if you have any of a long list of risk factors, including depression and smoking, or if you come from a socio-economic group that is more likely to suffer poor outcomes. It doesn’t matter if you’re not suffering from bad symptoms; one of the best reasons to take an intervention is to prevent long COVID, so get tested.
Lastly, you need to get tested because evidentially, people are terrible at knowing when to suspect they have COVID. Current symptoms of COVID mimic allergies, the flu, and a cold, and have begun to include vomiting and nausea again, as well as loss of smell and taste. While a RAT is unreliable for safe socializing with people, a molecular test can pretty reliably clear someone to come in your house that day, or be in close proximity. In that way, these molecular tests can be a tool to help immunocompromised people back into the world. The problem is that you have to be able to get one.
How to get a molecular/PCR test
This time last year, you could roll up to a truck in almost any city and get a rapid PCR test, paid for by the government or insurance, and have results quickly. The companies providing those tests have all left the space now, though, and if you want a PCR, you’re going to be hard-pressed to find one.
Your main options now are urgent care clinics and places that do testing for travel. In both cases, they’ll be expensive. In the case of urgent care, they’ll put you in the same space as all the sick people, who are now no longer required to mask in healthcare settings. Fortunately, there are PCR tests you can take at home.
You can take a rapid molecular test at home
Rapid molecular tests require a similar effort on your part as a RAT test. You’ll swab yourself and then insert said swab into a machine that gives you a result. There are currently just three brands of these tests available: Lucira, Cue, and Metrix. Unlike RAT tests, you have to mail-order them. For a long time, they were just too expensive for most people, so they were relegated to the likes of movie sets, law firms, and Google employees. Prices have gone down, so now they’re more accessible. Here are your options.
Lucira Check It Test
If you’re immunocompromised or COVID cautious, you’ve likely used a Lucira molecular test, because they’re usually the least expensive. These tests come with a disposable plastic hub (the testing machine), and the batteries needed for the hub (wasteful, sure, but at least you can keep the batteries). You set up the hub right before you take the test—like, right before, or the hub can error out. Then you swab your nose, insert the swab into the hub, and wait 30 minutes. The light on the hub will flash for 30 minutes until it reads positive or negative.
Having used these tests for the last year, and having given them to a wide swath of friends, they’re highly usable. Lucira was bought by Pfizer last year, and has just started producing tests again for this winter season, after a six-month lull in production. There are still tests available on the market, but not through Pfizer. A medical supply company called Peach Medical bought all the remaining stock and sells them, but note that the expiration dates may be coming up soon. Lucira tests run $25 to $45 a piece. They also gave Lifehacker a discount code PEACHMEDSUMMER20 to get 20% off your order.
One upside of Lucira is that because the entire kit including the hub comes in each box, they’re transferable. You can give a test to someone who needs it, because they don’t need access to your hub.
Cue COVID-19 Test and Hub
Cue Health inhabited an early space in the home molecular market, grabbing big accounts with Google, who gave all employees a hub (the testing machine) and tests. They are well put-together, and highly reliable, and generally very expensive. The hub has previously been about $200, but it is reusable with their COVID-19 test and a number of other tests they now have available (and units can be found for resale in all the places you’d expect). Even better, they’ve more recently started selling short-expiration bundles, meaning a batch of ten tests that will expire in six to 12 weeks, at a discount. For $300, you get 10 close-expiration tests (you’ll need to use them within one to three months) and a hub.
Cue tests come with a temperature sensor, so you know the tests were transported safely, and they include a nose swab that you insert into the hub to get a reading.
An additional upside of Cue is their followup service, called Cue Care, which is free. If you do test positive, they’ll connect you to a health care professional for possible interventions like Paxlovid. It’s just one less thing to worry about.
Although I’d been a Lucira user for the last year due to cost, these new discounts would be the enticement to move to Cue going forward.
Aptitude Metrix COVID-19 Test and Reader
Like Cue, Metrix is a reusable hub you purchase separately, and a test that you insert into the hub. The main difference is that you should be able to use either a nose swab or saliva for your test sample, which is a big step forward for people sick of sticking a swab up their nostril. (Generally, none of these tests require a deep swab, so it should never hurt.)
This is a brand new test that only entered the market a few weeks ago. Aptitude intends to sell it directly through their site in three to six weeks, but it has been available through Peach Medical for about a month. In interviewing people who had used these tests, a number of people complained about test units erroring out when trying to use saliva. When I spoke with Aptitude’s senior business operations manager, she chalked it up to user error, insisting the tests had an exceptionally low error rate, and suggested users simply use the swabs instead. As of Aug. 25, the tests seem to have been removed from the Peach website, so it’s unclear when they might become available.