“Natural immunity to a virus lasts years or decades, not months.” This statement used to be just a scientific fact based in the field of immunology. Unfortunately, due to the rise of Covid-19 this statement has also become political.
I went through school during a time when data drove policy and decision-making. And because of that, instead of entering a debate about how long our antibodies to the Covid-19 virus last, I decided just to measure them as a science lesson for my boys. Since February 2022, my boys and I have had our Covid-19 antibodies measured regularly. I’ve had us do this to teach them what I was taught about our immune systems and the efficacy of natural immunity.
The antibody tracking exercise, however, provided results that I hadn’t intended. My intention was to show that we still had antibodies long after 90 days had passed from having Covid-19. The results did not come out like I’d envisioned, because my boys and I kept getting exposed to Covid. We had Covid-19 in November 2021, January 2022, May 2022 (my oldest), June 2022 (me and my youngest), and August 2022 (my oldest).
But the real value in measuring our antibodies so frequently has been seeing how the memory cells in our natural immunity work. Memory B cells are a type of B lymphocyte that memorize characteristics of an antigen (e.g. a virus). They remember the same pathogen for a faster, more robust antibody production when reinfections occur in the future.
In our case, we likely had different variants that were predominant over time. In November 2021, it was likely the Delta variant. In January, it was likely the Omicron variant. Next, it was likely the Omicron BA.2. My oldest son’s latest infection was likely the Omicron BA.5 variant, as seen in the monthly levels below.
The variation in the different Covid-19 viruses is centered around how the spike protein of the virus binds to the ACE-2 receptor of the human cells. Likewise, the antibody blocks this spike protein binding. Each variation binds slightly differently to the ACE-2 receptor on the cell, in order to bypass existing antibodies.
As I mentioned in previous blogs, our symptoms became less and less noticeable with each contraction.
This culminated with my oldest son’s last infection in August, where he had no symptoms at all. And this is how natural immunity works. The memory B-cells combined with the existing antibodies mounted a rapid, highly effective response—so much so that he didn’t even realize he was sick. And his antibody levels went up 6.6 times or 660% during that time.
Continuing to track our antibodies as well as talking about natural immunity is significant for two reasons. First, there is still this idea circulating that you “lose your immunity” within months. This news article has an MD saying children lose their immunity in “four to six months,” which is false. Their antibodies may disappear, but their memory cells remain ready. Again, the field of immunology says that adults and children retain their natural immunity for years to decades because of these memory cells.
Second, as of this past May, 75 percent of children in the US were estimated to have a natural immunity to Covid-19. With the Omicron BA.5 outbreak in the US this summer, this number is likely to be in the 80 or 90 percent. This piece of information is important for parents who are considering getting their children vaccinated or boosted.
Parents should answer for themselves whether or not the vaccine or booster is still needed given that they have natural immunity. And they should answer whether or not the benefits of receiving the vaccine or booster outweigh the potential cost.
So, instead of entering the debate, I will continue simply to have our antibodies measured and report them here so you can make your own decisions and conclusions. This month’s antibody numbers are below. As you can see, they all dropped over the last two months, which is to be expected since we were not exposed again. But all of them remain very high. We will be testing every 6-8 weeks now, and will have another report in December!