From the Washington Post:
The document strikes an urgent note, revealing the agency knows it must revamp its public messaging to emphasize vaccination as the best defense against a variant so contagious that it acts almost like a different novel virus, leaping from target to target more swiftly than Ebola or the common cold. It cites a combination of recently obtained, still-unpublished data from outbreak investigations and outside studies showing that vaccinated individuals infected with delta may be able to transmit the virus as easily as those who are unvaccinated. Vaccinated people infected with delta have measurable viral loads similar to those who are unvaccinated and infected with the variant. The presentation highlights the daunting task the CDC faces. It must continue to emphasize the proven efficacy of the vaccines at preventing severe illness and death while acknowledging milder breakthrough infections may not be so rare after all, and that vaccinated individuals are transmitting the virus. The agency must move the goal posts of success in full public view.