Well to start, there's this: https://www.nejm.org/doi/full/10.1056/NEJMc2103825?query=TOC
However, that wasn't the article I was thinking about when I posted earlier.
This article points to some data that shows that the immune system response is slightly more robust in individuals that recovered from coronavirus and then received an immunization, compared to not getting immunized at all. Peer reviewed, but small sample size (they were collecting cells directly from lymph nodes): https://www.nature.com/articles/s41586-021-03738-2#article-comments
But your data from England is more current. There's also another Cleveland Clinic article that is leaning towards there not being as much of difference between natural immunity and vaccination, similar to the English stats.
I think this will get sorted out in the next year or so. Right now it does seem that the medical community consensus, as bleeding edge as it is at the moment, is that if you recovered from coronavirus, to get at least one shot, especially if you're in a more vulnerable demographic. I also think it's good news that the English research points to delta not really causing a high-reinfection rate.