Delta has been reported to have an R value anywhere from five to nine when not controlled.
disallowed/politics/nsw/nsw-s-extraordinary-vaccination-rates-give-it-a-fighting-chance-against-delta-20210823-p58l1g.html
https://fm.cnbc.com/applications/cnbc.com/resources/editorialfiles/2021/07/30/CDC_slides.pdf
