Do antibodies in your system guarantee immunity?

Do antibodies in your system mean you can do as you please, risk-free? It’s an appealing notion, but the numbers beg to differ. The real answers to this question are much more complicated than you might expect—the entire scientific community has spent the last few years trying to untangle this mess.

Do COVID antibodies guarantee immunity?

First things first: according to evidence from the CDC, fully-vaccinated people and patients who have already recovered from COVID-19 both exhibit some amount of protection from a reinfection for the first six months after recovery, though it may vary from person to person. While antibody tests were used widely previously, they have since fallen out of use, at least as an objective indicator of whether a patient is immune to COVID-19. The CDC is also vocal about another important fact: neither prior infection nor a full vaccination series are 100% effective against a new COVID infection later on. Mostly, these provisions serve their roles at the population level, minimizing new infections in a group setting. On an everyday, experiential level, however, there are no guarantees for the individual. What exactly makes one person less susceptible than another?

How does immunity work?

Immunological “memory” refers to the immune system’s ability to combat an infection it’s dealt with before. Once your immune cells have seen a given pathogen, they’re able to eliminate it quickly, preventing it from establishing itself throughout your body. Antibodies are proteins that patrol your bloodstream, targeting foreign particles, cells, and compounds and neutralizing them before they can wreak havoc. They’re not your only line of defense against viruses like COVID-19, however. In the absence of antibodies able to neutralize a pathogen, T cells, another key player in immunity, are also able to provide some protection against biological intruders like COVID.

Antibody vs. T cell response

Antibodies are actually secondary to cell-mediated immunity when the body is dealing with a coronavirus—it’s a trait that SARS-CoV-2 shares with its cousin, SARS. At the three-year mark, only 50% of SARS victims still have detectable antibodies in their systems. Virus-specific T cells, on the other hand, remain in abundance anywhere from six to seventeen years post-infection. Evidence suggests that the same is true for an immune response to COVID-19. The difference in a general sense has a lot to do with the severity of the illness—antibodies are usually deployed when the illness is advanced and aggressive, while T cells are the weapon of choice against milder illness. One theory as to why this may be: T cells are simply more effective, eradicating illness before it has a chance to develop into something much worse. Antibodies aren’t able to quickly sweep out microscopic baddies, and some animal studies show that introducing antibodies by way of vaccination might actually exacerbate the disease, making it worse. Again, it gets a little complicated. The point here is that antibodies aren’t the only reliable indicator of conferred immunity, but, instead, only one aspect of this multidimensional, system-wide response. Thus, antibodies don’t exactly guarantee perfect immunity against COVID—few things do, aside from a lack of exposure. While the presence of antibodies, or even of T cells, may mean that your body is armed and mobilized against a virus to some extent, the net outcome is, unfortunately, a matter of luck, chance, and fate. So it goes. Are you feeling lucky?

It’s a party in your bloodstream: T cells, antibodies, and immunity

So, in summary: do antibodies or T cells in your system make a quicker recovery more likely? Experts believe that both are important, and that a superior COVID vaccine should include both antibodies and compounds that induce a virus-specific T cell response. The focus thus far on antibody treatment for COVID, however, has usurped much of the industry’s inclination toward T cell activity when it comes to vaccine development. CoVac-1 is one vaccine candidate currently up on the block. It’s designed to stimulate the production of COVID-specific T cells in the recipient, eliciting a much broader immune response that smothers SARS-CoV-2 effectively and promptly.