RELATED: Virus Experts Have Stopped Going to These 4 Places as Delta Surges.ae0fcc31ae342fd3a1346ebb1f342fcb Scott Gottlieb, MD, a virus expert and former head of the U.S. Food and Drug Administration (FDA), told CNBC that he believes the Delta surge has reached its peak in the Southern states. “I thought there was an indication the South was peaking, and I think it’s pretty clear right now the South has peaked,” he said during an Aug. 23 interview on Squawk Box. Many Southern states, like Arkansas and Louisiana, were hit particularly hard by the Delta variant this past summer, largely due to these states having lower vaccination rates than Northern states. But as Gottlieb noted, “You look at states like Arkansas and Louisiana, you see the cases coming down.” According to The New York Times, new cases in Arkansas have decreased by 3 percent over the last two weeks, and in Louisiana, new cases dropped by 13 percent in the same timeframe. Gottlieb also pointed to estimated rates of transmission calculated by public health researchers at Harvard and Yale. The researchers measure transmission through the R naught model; when the R naught in an area is 1, it indicates that the average person infected with COVID there will spread it to one other person. When it is lower than 1, it indicates that the spread of the virus is declining. “The rate of expansion of this epidemic is below 1 in most of the South, which shows a contrasting epidemic,” Gottlieb said. RELATED: For more up-to-date information, sign up for our daily newsletter. This doesn’t mean there still won’t be lingering effects of the Delta variant’s surge in the South, Gottlieb continued. “It doesn’t feel that way because we still have a lot of new infections on a day-over-day basis, and the hospitals still have some very hard weeks ahead,” he said, noting that hospitals in the South are “still going to get maxed out as the infections start to decline.” And not all states are past the worst of it, either. On Aug. 13, the former FDA head told CNBC that the tri-state region of New York, New Jersey, and Connecticut will begin to see Delta cases rise once they slow down in the South. “This is a big country and the Delta wave is going to sweep across the country in a regionalized fashion. By September, hopefully you’ll see the other side of that curve in the South very clearly, but cases will be picking up in the Northeast, the Great Lakes region, maybe the Pacific Northwest,” Gottlieb predicted. He added that it’s likely the Delta surge will move across the country throughout September and October. “Hopefully we’ll be on the other side of it or coming on the other side of it sometime in November, and we won’t see a big surge of infection after this on the other side of this Delta wave,” he said. RELATED: You Must Do This to Protect Yourself From Delta—Even If You’re Vaccinated.