One of the things that happens to our immune systems with age is that a preponderance of naïve B-cells (in youth) gives way to a diverse body of memory B-cells (in older adults), each trained to respond to a specific pathogen from the past. (Valter Longo claims that fasting eliminates some of the memory B-cells, which are replaced by naïve B-cells upon re-feeding.)

We know that old and young people have very different responses to COVID and to the COVID vaccines. There is a link between the B-cell story and the differential responses of old and young if we look at a recently re-discovered phenomenon called original antigenic sin. (The term was coined in a 1960 article on influenza.)

(For anyone looking for the Christian theology in this blog, that was it. I apologize for the jokey headline.)

The innate immune system is our first and best line of defense. It is strongest in youth. Neutrophils engulf and digest bacteria and viruses. In addition to neutrophils and natural killer cells, there are short proteins in mucus membranes that protect us.

The mucus layer also contains substances that kill pathogens or inhibit their growth. Among the most abundant of these are antimicrobial peptides, called defensins, which are found in all animals and plants. They are generally short (12–50 amino acids), positively charged, and have hydrophobic or amphipathic domains in their folded structure. They constitute a diverse family with a broad spectrum of antimicrobial activity, including the ability to kill or inactivate Gram-negative and Gram-positive bacteria, fungi (including yeasts), parasites (including protozoa and nematodes), and even enveloped viruses like HIV. Defensins are also the most abundant protein type in neutrophils (see below), which use them to kill phagocytosed pathogens. It is still uncertain how defensins kill pathogens.


—Molecular Biology of the Cell, 4th Edition

How do these simple, generic defenses distinguish invaders from self? There are certain molecules that are characteristic of bacteria and absent in eukaryotes.

The pathogen-associated immunostimulants are of various types. Procaryotic translation initiation differs from eucaryotic translation initiation in that formylated methionine, rather than regular methionine, is generally used as the first amino acid. Therefore, any peptide containing formylmethionine at the N-terminus must be of bacterial origin. Formylmethionine-containing peptides act as very potent chemoattractants for neutrophils, which migrate quickly to the source of such peptides and engulf the bacteria that are producing them….Short sequences in bacterial DNA can also act as immunostimulants.


—Mol Biol of Cell, 4th Ed

Innate immunity is based on inflammation. I’ve seen several sources that describe how the brilliant, all-purpose system of innate immunity turns to chronic, un-targeted inflammation with age, but no explanation as to how the inflammatory response loses its way and attacks the body generally.

The great resistance that young people have to the COVID virus seems to be due to a strong innate immune system; conversely, the second line of defense, the adaptive immune system, which older people rely on, seems to have more trouble with COVID.

Original antigenic sin (OAS): When the immune system first encounters a pathogen, a tiny subset of randomly-generated antibodies that happens to match a subregion (about 120 AA bases) of some protein in the invader is copied in an exponential process that leads to enormous amplification. Thereafter, the body has a memory of some protein fragments of the pathogen, but not others. When the same pathogen is detected months or years later, the immune system will favor its remembered response, rather than exploring its naïve cells for a new one.

The problem called “original sin” arises when the new invader is a related pathogen, not identical to the one first encountered. The immune system recognizes some subsequences, and figures, based on its memory, “we’ve got this one covered”. But sometimes the response that worked well with the original pathogen is sub-optimal for the new one. The body may fail to fight off a new virus simply because it has encountered a similar one in the past. This is the phenomenon that Thomas Francis dubbed “original sin”.

The relevance to present-day pandemic epidemiology is this: Coronaviruses are ubiquitous, and have been around longer than humans; we have all been exposed to many of them. When our bodies first encounter SARS-CoV-2, they are likely to yawn and say, “this looks a lot like something I’ve seen before”. And indeed, this seems to work well for a lot of bodies. No less a light than John Ioannidis has estimated that up to 80% of people cast off the COVID virus with symptoms so mild that they never know they had it. But there are other people for whom the remembered response to some generic coronavirus is not sufficient, and their immune systems get stuck in an obsolete paradigm. Original sin.

“Original sin” can apply to vaccines as well. The COVID spike protein binds to the ACE2 receptor, and has this in common with spike proteins from many past coronaviruses. This makes it likely that parts of the SARS-CoV-2 spike protein have similar regions to other common coronaviruses from the past, (including the original 2003 SARS). The spike protein, of course, is the element of the virus that was chosen by all Western vaccine manufacturers to induce with their vaccine products. So we see a possible reason why young people and old people have such different reactions to the vaccine: young people are responding to the vaccine from the innate immune systems, while older people are responding by selectively amplifying antibodies from their immune memory.

Age and Vaccine Side Effects

The current crop of mRNA vaccines have caused in 11 months about twice as many adverse reactions, including deaths, as the total of all previous vaccines in the 30-year history of VAERS. These post-vaccination events deserve to be counted and addressed. CDC is in denial.

Reported heart attacks (9,746 cases) and deaths (19,532) after vaccination are skewed toward older people. The average age for heart attacks is 62. [these numbers from OpenVAERS]

Myocarditis and pericarditis (15,403) are skewed toward the young, average age 32, and toward boys more than girls.

When adults do have myocarditis following the jab, it is equally likely to be after the first or second dose. But when young people (