That is a formality in my book too.

But if you read on from where your citation stops (i.e. after "...on the diameter of the measles virus"), you find:

"Furthermore, the content of the publications submitted did not meet the requirements for proof. The phenomena presented therein as measles viruses are actually transport vesicles (bubbles) of the cell itself. None of the documentation submitted is based on attempts where the pathogen - as required - had previously been isolated and biochemically characterized or even such an isolation had been scientifically documented. [... (cut out some more things that are formalities to me)...] The determination of the diameter was also not well-founded. The size range of 300 to 1000 nm given in one of the publications presented already refutes the thesis of the virus, since viruses are characterized by a small variation in their diameter between 15 and a maximum of 400 nm. Incidentally, information from the RKI dated January 24, 2012 states that the diameter of measles viruses is said to be 120-400 nm and often contain ribosomes inside, although the latter contradict the existence of a measles virus."

What I get from this is:

1. The virus was not properly "isolated and biochemically characterized" and "isolation had been scientifically documented"

2. The diameter established by the evidence provided was not well founded, and greatly contradict other findings.

What Lanka's main point to me is, is that in order to scientifically establish the existence of a (sub-)microscopic infectious disease carrier, you need to first truly isolate it.

Not "claiming to have isolated it in virologist terms", that is: claiming to have it contained in a concoction monkey kidney tissue, bovine fetal serum, and more; thus in a soup with other DNA carriers. Because this "redefinition of isolation" makes it impossible to say we actually found it. Also we cannot sequence the DNA/RNA of the virus in order to establish it's identity, when we are testing a soup that has other DNA/RNA in it. (That's why virologists use "in silico" sequencing, which is not trustworthy either: especially not when other DNA/RNA is present in the sample)

Since the theory of viruses has become widely accepted, we have learned a lot about other sub-cell biological things with DNA/RNA in them, like exosomes. We have truly isolated them, and truly sequenced their genetic material.

But somehow for viruses with still cannot do that.

I hence hold the position that the hard-scientific evidence on the existence of viruses is very thin, or just not there. It's merely a theory at this point.

Only once the existence is established we can meaningfully establish contagiousness.

For instance with polio it is claimed by "the horrific anti-vaxxers" that the vaccine was introduced when the wave of polio-like symptoms was on the decline. And that polio-like symptoms are since also, conveniently, characterized as other diseases. So there are other reasons than the effectiveness of the vaccine to the disappearance of symptoms in the population.

Hence we need to establish first the virus exists and is contagious, or we end up with the vaccine's effectiveness being the proof of the existence of the virus. Which is basically what I believe is where we currently are. And a decline of the wave of polio-like symptoms
for other reasons can then easily be mistaken for effectiveness of the vaccine.

Therefor hard-scientific evidence is so important. Especially if states enact laws based on it, like we saw with covid measures and all state run vaccination programs.

Thanks for sticking to the discussion btw, I really appreciate you take the time to respond to my points that --i also know-- seem ridiculous from a mainstream viewpoint. Have a great day.