Coronavirus cases in Vermont are at an all-time high, but tests have been hard to come by.
Long lines and sold-out at-home test kits have become the norm. However, finding a test is only half the battle. It’s important to understand what each kind of test can do — and cannot do. Timing and cost can also be factors.
Results from the average PCR test — the kind you might get at a drive-thru clinic — may take a day or two to process. The wait could be even longer when the demand for tests increases. The labs that process the swabs often are closed on holidays and weekends, which could extend the waiting time for results.
At-home antigen test kits, retailing at roughly $25 apiece, are essentially a mini-laboratory complete with swabs, tubes and test strips. The testing process itself can be intimidating at first since it involves many steps, some waiting periods and a level of precision that the average person may not be used to.
Understanding the results is the other big issue, said William Schaffner, medical director of the National Foundation for Infectious Diseases.
“The average person thinks of a test as either positive or negative, and that all tests are more or less the same,” said Schaffner, who is also a professor of infectious diseases at Vanderbilt University. “And unfortunately, neither of those is true.”
As the Delta and Omicron variants of Covid-19 continue to spread, more people — including those who are vaccinated — will test positive, although so far the severity of the illness in vaccinated people is considerably less intense than in unvaccinated people.
Because of the highly contagious Omicron variant, Covid-19 cases have soared. Vermont reported 1,727 cases Tuesday and, as of Jan. 2, the state was averaging 785 new cases a day, a 123% increase from a month earlier, according to data from the Vermont Department of Health. State health officials expect cases to rise even more this month.
Here are answers to common questions.
What test should I use?
Most Vermonters have three options to consider: PCR, LAMP or antigen test.
- Most people are familiar with the PCR test, by far the oldest detection method. People usually get swabbed at a collection site or the doctor’s office. The swab is then put into a tube that’s sent to an off-site lab for processing.
The PCR, the “gold standard” of Covid-19 detection, can detect relatively small viral pieces with accuracy.
“If you’re positive, you certainly have a positive result” with a PCR, Schaffner said. “If you’re negative, you can (know) essentially 100% that you’re negative.”
But these tests are so sensitive that people who have had coronavirus can test positive for weeks after they’re no longer infectious, he said.
- The antigen test kits offer faster feedback and can be done entirely at home, but they are less accurate than the PCR. People generally need to have a lot more virus in their nose to get a positive result using that method, Schaffner said. Each test kit looks a little different and comes with slightly different instructions.
- Another at-home test, known as LAMP, gives people the same accuracy as PCR but without having to send the nasal swabs off-site. The kits, which retail at $75-plus apiece, are even more complicated than the antigen test kits.
The LAMP tests the state health department distributed to people over the holidays, for example, came with a battery-operated detector and a tube that has to snap into place for an accurate reading.
If you have time or you are looking mainly for accuracy, a PCR or LAMP test might be best, said Christi Wojewoda, director of clinical microbiology at University of Vermont Medical Center in Burlington.
People opting for at-home tests must carefully follow the instructions that come with their kit, Wojewoda said.
“If you just tickle the inside of your nose for a second, then you’re not collecting the sample the test needs,” she said.
What do my results mean?
All tests come with one big caveat: They offer only a point-in-time snapshot, Wojewoda said. That’s especially important with Omicron, a variant with a shorter incubation time than Delta.
Understanding the results is a little easier for people who have symptoms of Covid-19. If you get positive results from a PCR or LAMP test and have symptoms, you have Covid-19. A positive antigen test also offers some certainty but may require additional testing — and in the meantime, Wojewoda advises people to quarantine and reach out to their doctor for further guidance.
If you have Covid-like symptoms, but your antigen test comes back negative, test again the following day. It’s not uncommon to get a negative antigen test when the infection is just beginning, but then test positive as the virus advances, Wojewoda said.
[Looking for data on breakthrough cases? See our reporting on the latest available statistics.]
The situation is a bit more complicated when people without any Covid-like symptoms use an at-home test. A single negative result is not accurate enough to rule out Covid-19. A second or even third test over a few days could provide additional assurance.
A negative PCR or LAMP test can be interpreted with more certainty.
The bottom line? No test is perfect, Wojewoda said, and it’s important to interpret them correctly.
Where can I find a test?
The state offers free PCR tests at several sites, but appointments may not always be available.
Some pharmacies — including Kinney Drugs, Walgreens and CVS — offer PCR testing by appointment, but many testing slots are already full. As of Tuesday morning, for example, Walgreens locations in Essex Junction and Burlington were booked, while pharmacies in Rutland and Middlebury only had a few open slots in the coming days.
Rapid at-home tests are not always available. On Tuesday, antigen tests were completely sold out at the CVS online store. Target locations in Burlington and in nearby New Hampshire and New York state were also out. Some online retailers, including Amazon, have tests, but because shipping delays are possible, a test bought online may not arrive quickly.
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