Beware people wielding complex scientific terms. Their jargon is meant to confuse you.

The main concerns here are IgG4 antibodies. The video is a response to this paper suggesting that IgG4 could lead to T-cell exhaustion and, eventually, autoimmunity, but those suggestions are purely speculation at this time. We have no evidence to support those claims.

Scientific understanding of these immune cells is still evolving. However, this paper looked at the issue of IgG4 and offered that they make up only a small part of the antibodies that target the COVID spike protein after vaccination. The paper concluded that, overall, these antibodies are unlikely to weaken the immunity of vaccinated people.

We know perhaps a little more about T-cell exhaustion, as we see it in people who are constantly exposed to high levels of an antigen, such as HIV or cancer patients. We have no evidence that repeated vaccination could lead to that sort of T-cell dysfunction.

This question is still being studied, and more research is needed to understand it. Finally, no evidence supports the idea that mRNA vaccines are causing autoimmunity, and some research even suggests that vaccination protects against it.

In the study where the claim is made, researchers observed over 620,000 COVID vaccine administrations among children aged 2 to 5. They found that the mRNA-1273 vaccine was associated with a higher incidence of febrile seizures within one day after vaccination compared to the control period, while the BNT162b2 vaccine did not show a significant increase in febrile seizure incidence.

Febrile seizures, which are seizures as a result of rapid temperature change in the body, sometimes from illness, commonly occur in children 6 months-5 years old. They may seem scary but are generally harmless. With a population of 247,000 children, 100 of them having seizures is about what we would expect to see in a group of children that size.

Another study examined 795 children hospitalized with acute COVID infection, with 504 included in the analysis. Among them, 93 children (18.4%) experienced seizures during COVID. This suggests that COVID is a potentially more potent risk for febrile seizures than vaccination.

In June 2021, after the Italian government recommended the use of the AstraZeneca COVID-19 vaccine only in people 60 years and older, an 18-year-old received the shot and subsequently developed a rare form of blood clotting.

According to news sources, part of the investigation surrounding the medical staff was not that the vaccine was administered but that they failed to document that she had been vaccinated and to properly test for and treat her specific type of blood clot, vaccine-induced immune thrombotic thrombocytopenia (VITT).

While, exceedingly rarely, the viral vector vaccine can lead to VITT within weeks of vaccination, the United States currently has no viral vector COVID vaccines in use.