'IgG switcheroo' as in the phenomenon of antibody dependent enhancement, right?

No. I'll explain. The immune system relies on a basic recognition of "self" and "not self". Anything in your body that isn't part of you, that is, not your cell, not your tissue, not your protein, is "not self". Food, air you breathe in and out, bacteria, fungus, anything, that makes it into your body should register with your immune system as "not self". There's lots of different protocols the immune system goes through to judge the threat level posed by "not self" objects.

The protocols are divided by IgG groups 1-5. Each different group of IgG does a different policing mechanism to control "not-self" categories. For instance, some fungus and bacteria are healthy. In fact, you can't live with out them but they go to stay in a particular area and not go out of it. They're like guest that can only use the guest facilities. Every part of you has it's own bacteria and fungus ecosystem. We call it the microbiome. For instance, everyone has candida fungus on their body. The problem is when candida fungus is overgrown and causes the rash known as thrush or other problems.

Some IgG sits wherever your mucus membrances are: the eyes, nose, ears, butt, vagina, penis and mouth. I believe it's IgG 1, but also some IgG 4 is located in your openings. Other IgG operate inside the blood vessels and go to anywhere the skin has a wound and is bleeding. Nobody knows everything about IgG, but you might think of them as what decades ago, we called "white" blood cells, or immunity cells.

They all do different things. For instance, pollen from plants that we normally breathe in should be labeled by your immune system as an allergen, thus the allergen "police officer" which is IgG 4, should respond to this relatively harmless threat and just "escort" it out of the body. If your immune system over-reacts and sends in IgG 3, you have a severe allergic reaction and could die. The problem is the killer immune cells, IgG 3 is a "killer" because it doesn't just "escort" "not-self" particles out. It fights the "not-self" particles to the death, either them or you. It's a sterilizing sort of immune response that will not allow some particles to be present in your system. Mostly though, IgG 3 fights disease like strep throat, influenza and real sicknesses that can kill you so it's good to have this response. You want a robust IgG 3 response because it's your last line of defense against really bad things that find their way into your body. You don't want your body dealing with something such as strep with the allergen response IgG4 because you will die since strep will kill you. You don't want strep bacteria just being escorted out. You want the invader dead, torn apart and eliminated.

IgG3 should be the immune system response to the presence of SARS-COV-2 virus, even for those with no jab and natural immunity. For the vast majority of purebloods, a robust IgG 3 response is exactly what happens which is why pure bloods aren't getting sick anymore or just slightly sick. Natural immunity has trained your IgG 3 to recognize the SARS-Cov-2 virus as a significant threat and wastes no time in attacking it...at this point. Those who are SARS-COV-2 naive, that means they haven't had the virus at all, will likely get sick from it the first time, especially if they have low levels of Vitamin D3 and don't get a good source of vitamin C but after that, they will develop a strong robust and durable immunity to it because IgG will then recognize the SARS COV 2 virus and fight it to the death immediately. That's why most of us pure bloods aren't getting sick with this anymore.

Unfortunately, those who have been jabbed, especially if someone has received three or more mRNA jabs, have a dysfunction in their immune system. Their bodies are no longer treating the SARS-COV-2 virus like the threat it should be but treating it like an allergy. Thus, IgG 3 is not being activated when presented with the virus. Instead, IgG4 is being activated which is "escorting" and "policing" the virus in the body. It is not trying to get rid of the virus and stop the illness from progressing. It's just relabeling the virus "kind of sort of maybe self, but also allergen" Thus, the disease Covid, although "mild" in those who have had the jabs, is recurring on a regular basis because the immune system isn't treating it like a hostile invader. The immune system is treating it like it's allergen or a "friendly" microbe. The virus is staying in the system and multiplying and causing recurrences of health problems. For now IgG4 is kind of making the virus stay in a "compound" of sorts anywhere in the body but it's not eliminating the colonies of virus. (okay, the virus doesn't care about colonies like bacteria and fungi do, but the problem is, in this case, it's ACTING like it does).

SIMPLIFIED: The killer t-cells are treating the virus like it's allergen and not a threat. This is bad because SAR COV 2 virus is a threat, not the least of all because it's carrying the spike protein.

#eli5