The matter is somewhat technical, but important. A study involved taking antibodies from people suffering from Long Covid, and injecting this into mice. It was found that the mice, who had previously not been infected with Covid, developed Covid symptoms. It has been proposed that Long covid is similar to the Covid vax injuries, and some believe it is in fact a vaccine injury. The transmission via an injection of antibodies suggests that Covid can be transferred, via the blood, an issue which has been of concern to Japanese health authorities.
If it does prove to be the case that Covid can be transmitted via blood transfusions in humans, that is not a good reason to not have a blood transfusion, because if one is in a desperate situation needing a transfusion, Covid infection is secondary.
https://nakedemperor.substack.com/p/can-you-get-vaccine-side-effects
"A recent study titled "Transfer of IgG from Long COVID patients induces symptomology in mice" took antibodies from Long COVID patients and injected them into mice to determine whether they developed similar symptoms.
Whilst this study only looked at Long COVID, many people think some vaccine injuries are similar to Long COVID. In fact, a lot of people think Long COVID is actually a misdiagnosed vaccine injury.
What we can say for sure is that both Long COVID patients and individuals vaccinated with a Covid mRNA vaccine have changes to their antibodies. Remember all the studies from last year showing that the vaccinated had an IgG4 class switch whereby their bodies began to tolerate the Covid virus, instead of killing it off, as if it were a harmless fragment of pollen.
Anyway, back to the study - which is still a preprint so hasn't undergone a peer review yet. The purpose of the study was to determine whether antibodies were a cause or a consequence of Long COVID (remember this study is only looking at Long COVID but I am assuming it also applies to vaccinated antibodies).
To test this, the authors of the papers purified antibodies from patients' blood. These were then transferred into mice before the mice were tested for symptoms.
They found that after the antibodies had been transferred, the mice began displaying Long COVID symptoms. For example, the mice felt more pain when tested using a Von Frey test.
The scientists also tried separating the blood donors into different groups with different symptoms. Looking at the proteins in the blood they identified three separate groups (red/grey/yellow).
They found that antibodies from the different groups produced different symptoms in the mice.
Groups 1 and 2 had antibodies which targets proteins associated with the nervous system and immune cells. This can lead to increased pain sensitivity and chronic pain symptoms. When transferred into the mice they also showed an increased sensitivity to pain. This means they were more sensitive to touch and other stimuli.
Group 3 had antibodies that target muscle-related proteins, resulting in reduced physical activity and fatigue. Again, mice injected with IgG from this group showed reduced movement and activity.
By demonstrating that IgG from Long COVID patients can induce symptoms in mice, the research highlights the potential involvement of antibodies in the disease. It also suggests that any vaccine related antibodies, including the IgG4 class switch that has been occurring, can be transferred to another person via their blood."