Mercury in fish (split from Pfizer Vaccine: Long Term Side Effects)

[Alfred001]

On 7/8/2021 at 8:46 PM, CharonY said:

So that argument has some merit from a scientific perspective as they argue that the data provided is too thin to fully assess the pharmacokinetics of the formulation. Fundamentally this criticism has some merit and the context makes  more sense than the posts you have provided earlier. 

But before I get into that, I want to emphasize that in the context of OP long-term effects are not expected. For starters, even with incomplete data we see evidence of some elimination. As noted, the test concentrations was much higher relative to the animal weights as for the human formulation, so especially with hydrophilic compounds, it is likely that clearance will happen slower in rats compared to humans (i.e. more will circulate for a longer time). But more importantly, I want to point out the earlier argument with regard to monitoring health endpoint and its relationship to concentrations.

The rats were injected with 300-1000x the dose of their human counterparts (adjusted for weight) and a basic assumption of the effects of drugs is that they follow a dose-relationship (which is also the rationale behind PK and related analyses). So fundamentally you will expect the stronger effects when the concentration is high. Now with respect to the animal studies this has several implications. One is that the levels are massively higher than a person relative to their weight is going to encounter. I.e. any adverse effects should be pronounced in the animal. Second, clearance will be overall slower, as the small body needs to process a lot of material. For humans the relative dose is much lower.

So going back to the health effects, there were separate studies submitted to the various drug agencies based on injecting rats concentrations between 10-100ug of the drug three times a week apart (followed by a 3 week resting period) and compared to a control group. A snippet of the results is here:

In other words, even if injected with over a 1000x of the concentration of the drug several times, there was no indication of serious health effects other than inflammation (which is expected). The increases in the spleen were expected to be related to the inflammatory response, which can lead to the formation of blood cells, which is supported by bone marrow data. This was not the only study, another experiment was presented with more rats at single dose and also looked at organ abnormalities and found none. I.e. the toxicity studies directly look at damages caused by the vaccine components and the conclusion is that even at extremely high concentrations there are no unexpected damages in animal models. Thus, even if LNPs were lingering around, they would be as such low concentration that harmful effects are extremely unlikely. These findings are so far supported by clinical data in humans.

So together the point here is that one should not think that the one report is the full data provided to the drug agencies nor should one expect that any given data point can be easily extrapolated to health issues. Rather, different experiments provide different insights and the panel's job is to look at the full package and make a decision from there.

It would take a bit to explain how area under the curve analyses are conducted and how they are used, but I will for now note that full PK studies are often not required for vaccines. In part because you do not get regular doses of it, so that overdoses and similar events are not an issue. That being said, similar to the tox data, there is also more PK data out there covering about 2 weeks from which they estimated elimination rates:

The public details can be found either on docs provided by the European Medicines Agency, but equivalents should also be found from basically all approving countries. If you are interested in more detail how elimination rates are calculated I could do that if I have a few minutes, but should probably be a different thread.

I won't press this any further, thanks for the responses and the patience.

Let me just ask you something unrelated to the vaccines, if we can take the thread on a very brief digression and if this is a topic you know about:

This business about eliminating lipids got me thinking about something I've often wondered (and worried) about, which is mercury in fish. You'll usually hear that you SHOULD eat fish, but not more than x servings of such and such fish a week.

Is that because if you don't cross a certain threshold of mercury in a given time it will get eliminated without having an effect, whereas if you go beyond that it doesn't get eliminated quick enough and could have some negative effect?

[CharonY]

Yes, basically. At very low doses most mercury can be excreted with a half life of a few days to two weeks. However, especially at higher dosages the excretion pattern becomes more biphasic with a the fast phase (i.e. <2 weeks half life) only eliminating part of the ingested mercury. The rest follows a much slower (1-2 months half life) elimination pattern.

If your intake outpaces the elimination time, you start accumulating which can result in issues.