Research confirms that T-cells hold the key to lasting immunity against COVID. While most of us are familiar with the notion that antibodies protect us against a specific virus, it is not as well known that antibodies can fade, sometimes even after just a few months. T-cells, however, hold a cellular memory of infection for years, sometimes decades. Further, T-cells are the cells responsible for telling the other immune cells what to do and coordinating a full-fledged response. In a sense, the T-cells are the commander-in-chief and the soldiers of the immunological army.
The human immune system falls into two major categories – innate and adaptive immunity. The former is present at birth and is the immune system’s more primitive way of protecting us by directly attacking viruses or cells that have been infected by a virus. The latter (adaptive) is the immunity we acquire over the course of our lives as we become exposed to different pathogens, either through natural infection or vaccination.
T-cells are unique because demonstrate properties of both innate and acquired immunity.
In contrast, antibodies are ‘acquired’ over a lifetime. When we’re born, we do not have antibodies to the viruses and bacteria waiting in the world around us. They develop when we get exposed to a pathogen. In other words, we acquire immunity via antibodies (also known as B-cells, named for Bone marrow, where they are made).
The genius of the T-cell (so named because they come from the Thymus gland) is that they regulate both arms of the immune system.
There are actually many types of T-cells, all with a specific function. Some T-cells directly kill infected cells – like an army soldier. Some T-cells tell the blood to make antibodies. Some T-cells communicate to surrounding tissue to settle down and slow the immune response, so the host (that’s us) doesn’t sustain too much collateral damage. It is really quite exquisite how the T-cells, in a well-functioning immune system, coordinate everything at the cellular level.
But T-cells do something even more interesting – which is to keep a memory of what the virus looks like so we recognize it (or its close cousins, molecularly speaking) in the future. That is what we ultimately want – a lasting immunity that comes in the form of “cellular memory.” T-cells are what make this happen.
In people who were infected with the first SARS virus (now called SARS-CoV-1) in 2002-2004, they have T-cell memory of the virus, which means immunity, nearly two decades later. Circulating antibodies, on the other hand, were gone. But this is good news – for those with T-cell memory against the COVID-19 virus, they may have long-lasting immunity.
The referenced 2021 paper in the medical journal Immunity lists four hallmarks of T-cell immunity:
- Ability of T-cells to recognize the virus (via special receptors on its cell surface)
- Ability of T-cells to respond quickly when it “sees” the virus
- Ability of T-cells to remember what to do in order to fight it
- Presence of T-cells in barrier tissues (like nose & throat) that are first to encounter a virus
It states that “even in the midst of an active infection, the immune system makes an investment in the future of the host by selecting activated T-cells to become memory progenitors.”
In other words, the immune system is smart enough to worry about the future, even amidst a crisis. It is a well-functioning T-cell that makes it possible.
SpectraCell measures T-cell function as part of its flagship test, the Micronutrient Test.
(Immunity, January 2021)
LINK to FREE FULL TEXT T Cell Memory: Understanding COVID-19