It's important to note, his letter is a "call to action", it is not in any way a study or scientific report.
Letters generally aren't.
His call to action was to ask the WHO to call a halt and debate their next actions with him and whichever other world renowned virological scientists they chose.
Hardly the actions of a charlatan, he obviously knows that he has got the science behind him to back up whatever he is planning to say.
Have you actually watched that video?
There were a number of other claims he made.
For a start he repeated the claims made by thousands of doctors world wide that lock downs and face masks were the absolute worst thing that could be done in the face of a new virus, which only the very old or otherwise immuno compromised are vulnerable to.
Everybody else should be out there as normal intermingling and catching the virus, because everybody is born with an immune system that can handle it, and catching that virus makes everybody's immune system stronger .
As those doctors all say, the vulnerable should be shielded while the rest of us get on with our lives.
He said a lot more than that, talking about how using a prophylactic vaccine while in the middle of a pandemic is the worst time to use it.
And doing so will result in turning what started as a relatively mild virus into a deadly killer on the lines of the more deadly virus's that we know.
Put that together with his claim that the body's innate immune system will be severly hampered and prevented from doing it's job by the vaccine, which targets the original covid virus, and which will be a lot less effective against all the new variants which he says are coming out, and which he says are brought about by using the vaccines while in the middle of a pandemic.
He says that the current actions will lead to a steep drop off in death rates, then a plateau of some length, then an ever steeper rise in death rates as the new, stronger variants develop, which the vaccines, and the body's immune system can not handle.
And the ever stronger variants will be just as dangerous to those like myself who will never take the vaccine.
In other words, this absolute advocate of vaccines is saying that you people taking that potion are going to kill us all.
If you want to know the science behind his claims watch the video.