The question is not what causes Covid-19? We know it is caused by the virus, SARS-CoV-2. And we know quite a lot about the virus and the disease. Thousands of studies and articles have been published on this virus and disease to-date. The question is what causes a particular version of Covid-19, in which the disease continues indefinitely. Usually, a mild case lasts 1 to 3 weeks, a moderate case lasts 2 to 4 weeks, and a severe case can last well over a month. But the “longhaulers” type of Covid is not severe, but moderate, and yet it is not cleared within a month or so. Some “longhaulers” have been sick since March or April, and it’s now August.
I have a hypothesis as to what causes Longhaulers Syndrome. It’s described on my Covid blog here: The Longhaulers Hidden Virus Hypothesis and in the follow up article here.
It turns out that this hypothesis was first proposed by William Petri, MD, PhD. of Univ. of Virginia Medical School in this article here. And that just increases my surety about the hypothesis.
Ronald L Conte Jr
the reproach of Christ 
Ron,
Have you heard of vaccinologist Sarah Catherine Gilbert (better known as Sarah Gilbert)?
It’s been rumored that she might already have the vaccine against Covid-19. According to Wikipedia, her candidate vaccine could be available by September 2020.
The following is an article from Bloomberg.com:
https://www.bloomberg.com/news/features/2020-07-15/oxford-s-covid-19-vaccine-is-the-coronavirus-front-runner
I have heard of her vaccine, the Oxford vaccine. It will not be ready by September. In April, she hoped she could hit that date, but recent reports say it will take months longer.