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
When I look at (delta variant) the number of deaths and nothing else, the vaccinated come out only slighter better than the unvaccinated. However, the overall risk of death is from the Wuhan virus is much lower than the risk from taking the vaccine itself.