In other words, natural infection offers a much better shield against the delta variant than vaccines.
The study was described by Bloomberg as "the largest real-world analysis comparing natural immunity - gained from an earlier infection - to the protection provided by one of the most potent vaccines currently in use."
“It’s a textbook example of how natural immunity is really better than vaccination,” says Charlotte Thålin, a physician and immunology researcher at Danderyd Hospital and the Karolinska Institute who studies the immune responses to SARS-CoV-2. “To my knowledge, it’s the first time [this] has really been shown in the context of COVID-19.”
Study: https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1
This just sets the stage for the next round of vaccines after they change them to meet the mutation