Those "repositives" are not infectious cases though.

https://www.nature.com/articles/s41467-020-19802-w

"There was a low repositive rate in recovered COVID-19 patients in Wuhan. Results of virus culturing and contract tracing found no evidence that repositive cases in recovered COVID-19 patients were infectious, which is consistent with evidence from other sources."

Same paper also states that asymptomatic cases are much less likely to be infectious.

Better to say the vast majority of them are later viral shedding or very minor, probably not contagious cases.

There's probably been a few reinfections, and some decent documentation of a couple. If you repeat an experiment millions of times on diverse individuals, you can expect some variation.

There have been cases when genomic analysis was performed during the two infections and it "showed genetically significant differences between each variant associated with each instance of infection".

So reinfection actually is possible.

https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

No. You’re talking about 2 or 3 cases out of millions. It’s very rare to get it twice.

As far as i know, there has been multiple cases in Finland alone. There has been multiple news reports regarding to it. We just don’t know the extent of it yet.

As far as I know the number is way lower than the immunization of the Vaccines and the false positive rate of the tests.

If your immune system failed to get trained by the virus, wouldn't that apply to the vaccine also?

No. The vaccine is a concentrated flood of the proteins that are necessary for the immune system to target the virus.

There are vaccines that cause better immune response than the disease it protects against.