State and local health officials warn against current antibody tests
April 30, 2020
The first antibody tests have begun to appear on the market, both to purchase online and through a few providers in this region. But are they worth taking, this early in the game?
The answer is no, according to both state health officer Dr. Alexia Harrist and Dr. Heith Waddell of Crook County Medical Services District. At this time, the FDA has not yet approved any antibody test for use.
Some are better than others, says Waddell. Some, said Harrist at Governor Mark Gordon’s press conference last week, are “downright fraudulent”. None of those available so far are completely reliable.
“After a couple of weeks of having a virus, whether it be COVID-19 or any other, your body develops antibodies to these viruses. Through a blood test, those can be detected,” explains Waddell.
“They are trying to build a reliable one for COVID-19. Unfortunately, we’re not quite there yet.”
There have been mentions of FDA-approved tests in recent reports about the pandemic, but Waddell cautions that these are not truly approved and are not intended for common use.
“There are some tests that have been approved for emergency usage by the government – what’s called ‘EUA approved’, which is ‘Emergency Use Authorized’ – but these are not tested properly or over the long term,” he says.
Waddell explains that a test is ranked according to two factors: its sensitivity and specificity. The higher the number, the better the test.
However, while a test that scores 90% on these measures may sound great, that’s not necessarily the case. A percentage of those tested will receive a result that tells them they have already contracted COVID-19 when, in fact, they have not.
“If I say it looks like they have antibodies and can go out into the community and do whatever, and they do that – well, maybe they haven’t caught it yet and maybe they are going to catch it and then spread the disease because they thought they’d already had it,” he says.
Should we, as a state, be considering widespread antibody testing?
“The answer is actually yes, but we have to make sure we have the appropriate test and that the test is accurate,” Waddell says.
CCMSD has discussed offering antibody tests, but decided the downsides would outweigh the benefits. If a test came back as positive that the person had experienced COVID-19, it would be difficult to tell the patient that with any conviction.
“There is actually a margin of error on the negative too but, if we told them they were negative when they actually have had it, there’s no increased detrimental effects of that,” he says.
“But obviously if I tell somebody they are positive when they’re not and then they go out and get sick, that’s troublesome.”
It takes time to develop the medical tools needed to fight disease, he continues.
“A lot of research papers and studies are being done on COVID-19 right now – there are literally hundreds of papers coming out every week. The problem with these is that they are not peer reviewed and so they haven’t gone under the normal scrutiny of science,” Waddell says.
“It really does confuse the message we’re trying to send to people.”
Should you purchase an antibody test right now? Save your hard-earned money, he says.
“I think people have to be careful. Certainly, I would be very cautious about buying the at-home tests because it can be dangerous if the data isn’t correct,” he says.
“It would be great to know where all the people are in Crook County who have the disease or have had it, but I just don’t think we’re there yet with the appropriate testing.”
On the other hand, when antibody testing does become more reliable, it will almost certainly be one of the most powerful weapons in our arsenal against the disease.
“There is a lot of stuff in the pipeline. They’re trying to come up with vaccines, they’re trying to come up with better treatments, they’re trying to come up with ways to recognize it earlier,” Waddell says.
One day, COVID-19 could be like the chicken pox: a few decades ago, it was an illness most kids experienced, but today it is rarely seen thanks to the vaccine.
“This may be something where they eventually develop a vaccine but I think there are still a lot of unknowns and, as many questions as we have, there are researchers all across the world putting in 10 or 16 hour days trying to make this safer for people,” he says.
“They are in the pipeline, but it just takes time.”
For that reason, Waddell stresses that cautious behavior is our best option as a community.
“We still need to practice social distancing, we still need to be really careful at this time,” he says.