Should Your Company Test for Covid Antibodies?

a scientist holding a tube test at a laboratory

As Covid-19 continues to be a serious concern for businesses and individuals, one issue keeps popping up. Before you bring employees back into the workplace or hold any in-person events, you want to ensure everybody will be safe and remain productive.

Determining how safe your events are will primarily depend on two things. First, is anybody sick? Determining whether someone has Covid, and recognizing that ~50% may be asymptomatic, is what diagnostic tests are for, including lateral flow antigen tests, microfluidics antigen tests, and PCR (Polymerase Chain Reaction) tests. Second, what level of immunity do your attendees have to Covid, either from vaccinations or having already had the virus in the past? Determining that immunity is what antibody (Ab) tests are for.

Ab tests are serology tests, meaning they look for antibodies in your blood. They do not tell you whether you currently have Covid but rather whether your system has antibodies against the virus. But what exactly is an Ab test and what do the results really tell you?

Right now, not a whole lot. Covid Ab tests are currently not a reliable method of determining immunity, or whether you’re safe going back to work or attending a large-scale in-person event. Instead, they are best used simply to find out if someone has had Covid in the past. One reason you might use them is if someone is suffering from long-term symptoms that may seem Covid-related and it’s affecting their work. New research published in the AMA suggests that long-covid is more prevalent than previously thought.  An antibody test could help you determine that those symptoms are related to Covid.

To understand how an Ab test works, you first need to understand antibodies.

Understanding Antibodies

Antibodies, also called immunoglobulins, are the proteins that your body uses to fight against disease. There are different types of antibodies to defend against different diseases. Vaccines create immunity against specific illnesses by generating specific antibodies.

For example, if you received the chickenpox vaccine as a child, then your safety from the disease came from your body creating antibodies that could recognize the illness and fight against it. The same principle goes for the Covid-19 virus. A Covid antibody test specifically looks for antibodies that target that specific virus.

So the goal of a Covid antibody test is not to figure out whether you have antibodies in general, since we all do, or whether you currently have Covid. The question is, do you have Covid-neutralizing antibodies? Can your immune system recognize and fight against the virus if you’re exposed, or are you likely to get sick?

There’s a misconception that if you’ve been vaccinated against Covid, you’re automatically safe from the virus. The problem is, vaccinations are generally only effective for 5-6 months, hence the need for boosters. The level of antibodies declines over time. Plus, vaccinations can’t always target each new variation of the virus effectively.

For example, the differences between the delta variant last year to the omicron subvariants that are currently affecting us is significant. So a lot of people who got sick from delta also got sick from the omicron variant. On the other hand, omicron subvariants don’t have the same level of difference from one to another, so if you got a vaccine or contracted Covid during the BA.1 surge, it will probably be pretty effective against BA.2 as well (with regard to hospitalization and death).

Since immunity wanes, it is not enough today to ask “if” you have been vaccinated. What you really need to know is whether your employees, or those attending your events, have recently been boosted or have contracted the virus recently enough to ensure best-in-class safety.

Antibody Tests

Some Covid Ab tests can tell you if you have Covid-neutralizing antibodies in any measure. You need to be asymptomatic before you take an antibody test, and the test often needs to be overseen by a medical professional.

Right now, most Ab tests are qualitative, which means they just tell you whether you have the antibodies, not how many you have. Qualitative tests can occasionally give false positives, meaning they might say that you have Covid-neutralizing antibodies when you actually don’t. The more specific a test is, the less likely it is that there will be a false positive.

According to the FDA, most Ab tests have low specificity in regard to the type and concentration of protective and neutralizing antibodies, so they can’t actually tell you well enough whether you’re immune to the Covid-19 virus. They don’t tell you whether you have enough antibodies to provide full immunity, and not every Covid antibody test can detect the specific antibodies that result from vaccination.

Again, the reason to use qualitative antibody tests is to see whether you’ve had Covid-19 in the past. If you have had Covid in the past, you could be immune for up to a year after infection, and potentially considerably longer if you’re also vaccinated.

The most important thing to keep in mind is that people shouldn’t stop taking any of their usual precautions just because they get positive results on antibody tests. The safest bet will still be to for people to receive booster vaccines on a regular basis, around every six months. Companies should also continue with regular testing as well – and specifically for example at indoor corporate events and meetings.

Diagnostic Tests

If you want to know whether it’s safe for employees to attend meetings or corporate events, antibody tests won’t tell you. You should seek best-in-class, highly accurate point-of-care (POC) diagnostic testing. POC testing means you can test your employees in the workplace or right before a meeting and find out whether or not they currently have Covid-19.

While you may be tempted to rely on conventional antigen tests, also called “rapid” tests or “at home” tests, their results are often inaccurate. In fact, accuracy levels can be as low as 38% for asymptomatic individuals. Professionals recommend you confirm negative results with a PCR (polymerase chain reaction) test. These tests are much more accurate, but results often take several days, so they’re not always practical for event testing.

A much better option is the highly-accurate, FDA- and EAU-approved microfluidics antigen tests, like the one offered by AllClear Healthcare, which provides the greatest peace of mind for employees coming back to work, HR professionals, event planners, and Environmental Health and Safety (EHS) managers. You can get results comparable to the accuracy of a PCR test (80% to 90%) in minutes instead of days.

The landscape for managing Covid-19 changes daily, and right now there’s no test to definitely say if you’re immune to infection. What you can do is provide best-in-class POC testing and vaccination monitoring to keep your employees and their family members safe.