Bingo! Even DHS admits it.
...we asked state health officials to estimate how many Americans have been exposed to the virus.
"Now, a year a year and a half into the epidemic, seems like a reasonable estimate could be that about a third, maybe even higher than that of people in the US have been exposed," said Dr. Ryan Westergard, chief medical officer for communicable diseases at Wisconsin's Department of Health Services....
About half of the US is vaccinated. Combine that with 33% naturally-immune from having had the disease, and we are well into the requirement for herd immunity, the lower end of which is 70%.