Biologyfag here. Not an immunologist, but I play one on TV. Putting together a couple of bits of data here…
p. 1:
1) Internal Pfizer vaccine study from Japan, available on government regulator's website (attached for posterity, but for your safety and peace of mind you can get it from them):
https://www.pmda.go.jp/drugs/2021/P20210212001/672212000_30300AMX00231_I100_1.pdf
2) Reuters "Fact Check":
https://www.reuters.com/article/factcheck-vaccine-safe/fact-check-no-evidence-spike-proteins-from-covid-19-vaccines-are-toxic-idUSL2N2NX1J6
“We can confirm the document does not make any reference to spike proteins from the vaccine resulting in dangerous toxins that linger in the body – this claim is incorrect”, the spokesperson said.
3) https://byrambridle.com "fact check" website (NOT Dr. Bridle's website.)
"There is no spike protein in the mRNA vaccines:"
All true. There is (purportedly) no spike protein in the vaccine itself. But what does the mRNA in the vaccine do?
4) (image attached) 48-hour mRNA lipid nanoparticle concentration in Wistar rats, from 1), table 2.6.5.5B.:
https://www.scienceforums.net/uploads/monthly_2021_06/1014698625_ScreenShot2021-06-20at17_55_29.thumb.png.c267f528ecfca1dc5301658cfb44f2d4.png
The mRNA is packaged in lipid (fat) nano- (extremely small) particles in the jab. The Pfizer document contains measurements of the concentration of these lipid nanoparticles in different organs and tissues in Wistar rats over time, from 15 minutes to 48 hours after injection. In other words, they jabbed a bunch of literal lab rats, "sacrificed" that means killed 1 out of 7 of them after 15 minutes, and the same number after 1 hour, 2 hours, 4 hours, 8 hours, 1 day, and 2 days. Then they dissected them, likely pureed the pieces, and used some sort of radiation sensor to measure the concentrations of tritium (radioactive hydrogen) put into the nanoparticles beforehand.
The concentration of particles still found at the injection site after 48 hours was 165 micrograms (µg) per milliliter (mL). An equivalent measure would be milligrams per Liter. To give an idea of the ratio, a Liter is a bit more than a quart, and 1000 grams (a kilogram) is about 2.2 pounds. A (very) loose translation of the ratio of 165 mg/L is 165 parts per million. 165 parts per million doesn't sound like a lot, but remember, this is for whole tissue. 1 million / 165 is one part in 6060, for everything in the tissue, extracellular stuff, cell membrane, intracellular stuff, and a bunch of water. It's a lot.
What happens to the lipid nanoparticles over time after injection? From 15 minutes to two hours, they become detectable in their highest concentrations over time at the injection site (394 mg/L after 1 hour), and in Whole blood (w/red and white blood cells, 5.40 mg/L) and Plasma (just the liquid part, 8.90 mg/L) after 2 hours, where the plasma makes up a bit more than half of the blood volume. They also reach significant concentrations after two hours in the Liver, Spleen, and Kidneys, which are likely attempting to filter/degrade/detoxify/remove them. While 8.90 in the blood after 2 hours seems a lot smaller than 394 at the injection site after 1 hour (311 mg/L after 2 hours), remember that the volume of the injection site is much smaller than the volume of the blood in the rat. Without looking up the average blood volume of mature male/female Wistar rats, it is safe to say that a very large fraction of the injected nanoparticles do not stay at the injection site.
Over the next 48 hours, the concentration at the injection site goes down by about half, the concentration in the blood goes down, and the concentrations in the Liver and Spleen continue to go up. This means that nanoparticles from the injection site continue to leave the injection site, carried away predominantly in the blood plasma, whence they are free to enter cells in other tissues. The fact that the blood concentration continues to go down even as lipid nanoparticles are being released from the injection site further underlines the difference in volume between the injection site and blood. Aside from the injection site, the highest organ concentrations after 48 hours are in the Liver and Spleen.