Dr. Jerome Adams, former U.S. surgeon general, started a national conversation this weekend when he said he and Dr. Anthony Fauci had been wrong last year when they initially advised against masks and that he worries federal health leaders could be making the wrong move now, too, as cases grow in some places.

Adams spoke to WISH-TV about why now was the right time for him to speak up, how to talk to vaccinated people about putting the masks back on, and what he hopes to see from local health representatives.

In a Saturday evening thread on Twitter, Adams said he and Fauci “famously, prematurely, & wrongly advised against masks,” and that while he thinks they made the best decision they could at the time, he regrets it.

Adams said he and Fauci based their recommendation on the conditions at the time, in an effort to “save the medical masks (which were all that was available) for the medical workers,” he said in the tweets. But conditions changed from that time, and they continue to change now, Adams said.

As cases of COVID-19 rise due to the Delta variant, Adams said he worries the U.S. Centers for Disease Control’s recent guidance that vaccinated people can forgo masks is “a similarly premature, misinterpreted, yet still harmful call.”

Now there’s a push for some cities and counties in the U.S. to bring back masks in the face of rising COVID-19 cases, including in Los Angeles County, one of the nation’s largest, where all people are once again required to wear masks regardless of vaccination status.

Adams said we’ll likely see more cities and states issuing guidelines that are “in direct conflict (with) the mask guidance” issued by the CDC in June. His suggestion: “The sooner CDC says we were wrong, & hits the reset button, the better. Trust me- I know more than anyone.”

According to Adams, the emerging data on COVID-19 “suggests CDC should be advising to vax it AND mask it in areas with” rising “cases and positivity- until we see numbers going back down again.”