This is directly contradictory to the evidence I've seen (https://pubmed.ncbi.nlm.nih.gov/34103407/ https://pubmed.ncbi.nlm.nih.gov/34103407/ for a publication,

This is directly contradictory to the evidence I've seen (https://pubmed.ncbi.nlm.nih.gov/34103407/ https://pubmed.ncbi.nlm.nih.gov/34103407/ for a publication, this article based on a similar study: https://directorsblog.nih.gov/2021/06/22/how-immunity-generated-from-covid-19-vaccines-differs-from-an-infection/ https://directorsblog.nih.gov/2021/06/22/how-immunity-genera..., and this https://www.medrxiv.org/content/10.1101/2021.04.25.21256049v1 https://www.medrxiv.org/content/10.1101/2021.04.25.21256049v... which suggests that you get a boost from the vaccine even if you've had the virus). In other words, there's strong evidence that you get a stronger immune response, for longer, that is more effective against variants with the vaccine than with a natural infection. The paper I think you're referring to (https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v2.full.pdf https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v...) states "It is not known how well these results will hold if or when some of the newer variants of concern become prominent. However, if prior infection does not afford protection against some of the newer variants of concern, there is little reason to suppose that the currently available vaccines would either. Vaccine breakthrough infections with variants have indeed been reported [17]", but this is directly contradicted by some of the other studies I cited, that to show better protection against variant re-infection.