There is a very clear, highly restrictive policy in two cases against use of animals in testing. Even if reagents conflict with that policy (which calls into question their capability as research leaders), it is still highly restrictive in a field which does not need any additional hurdles.
I'm not so sure. To me it shows the discussion is more nuanced and that one should be informed about these nuances before one makes conclusions or even accusations. Here is one of plenty examples of a project that was partially funded by ME Research UK in which mice were involved
https://www.sciencedirect.com/science/article/pii/S2666354620300120, here's another
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0024602 and here's another . I don't think this has to be explicitly mentioned by anyone because anybody involved in research or carefully reading the studies is probably extremely well aware of all these things.
So why would a study involving 200 mice be so guargantuan then? 10 - 100 million is the number of mice used annually.
Because this would be a far more extensive and longer setup than in most other experiments in which mice are used annually. I'm not sure 200 mice would be sufficient. Probably more than 1000 (i.e. several hundred), but that is an extremely crude estimate if we accept the assumptions initially made, maybe it would be far less or even more, who knows. An experiment where you give mice some cosmetics and see whether there is a short term reaction is a much easier set up than the one proposed, where you have to infect mice and inject a control solution in your controls, run behavioural tests on all of them for an extened period of time, longer than most mouse studies even take, maintain them under specific pathogen-free conditions in well ventilated cages with equally distributed and continuous access to food and water in a temperature and humidity controlled room with specified day and night cycles making sure control mice are kept under the exact same conditions, in the same cage, whilst making sure there is no infectious spread between controls and infected mice as you co-house them 1 to 1, making sure they are acclimatised to their surroundings when performing each test, making sure all experiments are always performed at the same time and following the same pattern over several months if not years etc. There's an extreme amount of potential noise in mouse studies which means you have to have to be extremely careful and have multiple levels of controls making the task extremely laborious. Iwasaki’s study took larger efforts, so did the one by den Dunnen, why is this the case if they just used a handful of mice and a few patient samples they anyways already had access to? Why did Iwasaki only perform her mouse experiments with 4 patients and 4 controls if this is all so quickly done? Running all the necessary tests on one mice takes alone takes multiple days of work, just image having to do that repetitively for a long-term mouse study (which neither den Dunnen, nor Iwasaki nor the study you had cited did) and that for hundreds of mice.
If you're studying something "rare" (for instance ME/CFS or long-lasting LC phenotypes) that happens following a common event (for instance Covid-infection or EBV) you will always need massive sample sizes if you don't start your study with those that are ill (thousands is a low example Ascherio needed more than 10 million in his EBV-MS study and even at that sample size it yields completely unreliable rates, in the above setup you'd probably be able to get away with a much smaller sample size if you can indeed control the number of genuinely uninfected controls).
To ask whether mouse research has been useful in past ME/CFS research in order to justify its future use is not a reasonable hurdle to set.
Frankly there has been so little research up to now that past ME/CFS research cannot be used as a benchmark of what good looks like.
At no time point did I ask about past mouse research in ME/CFS, which obviously would never be a good benchmark for any research in ME/CFS. I’m asking whether you had any examples of past mouse research leading to breakthroughs that would be applicable to ME/CFS, rather than general examples of mouse research in medicine, which is something you have not been able to supply. One would have to ask someone that is actually knowledgable on the subject, but it seems Myasthenia Gravis could be such an example.