I totally agree with your point re: the need for data. I would push back a bit on the rhetorical issues with conflating traditional 'antivaxxers' with everyone who may be skeptical of these vaccines. It's not clear that these issues can be meaningfully grouped together on an ontological level.
Sorry about that. It isn't really anything to do with the vaccines. It is simply something that may help others, since some unfortunate few (very small %) are even getting "long covid" from just the vaccine alone.
Niacin appears to be very well studied, but not in the context of post-viral illnesses. But there are a mountain of papers which may help to explain why it works. Here are a few:
Why do you hate antivaxxers - are you trained in medicine, molecular biology, etc. or is this nothing more than orthodox ideological position?
The scientific method and science itself is NEVER SETTLED. And it is always advanced from discussion including anecdotes that become more formal research.
Up to 1000mg once per day now, but had to work up slowly over a couple of months, as I wasn't able to tolerate even 10mg at first. You need the "flushing" type of nicotinic acid (it causes your skin to go hot and red for about half an hour, but tolerance of this gradually increases), avoid the "slow release" or "non-flushing" forms of Nicotinic acid. For melatonin I started on 3mg and worked up to 9mg.