Reprinted with permission from Alternet

COVID-19's highly infectious Delta variant has been causing considerable misery in the U.S., especially in red states with low vaccination rates. And according to expert immunologist Dr. Anthony Fauci, a COVID-19 variant that is even worse than Delta may wreak havoc in the United States if more Americans don't get vaccinated.

In an interview with McClatchy, the 80-year-old Fauci — who heads the National Institute of Allergy and Infectious Diseases and is President Joe Biden's chief medical adviser — warned, "What we're seeing, because of this increase in transmissibility, and because we have about 93 million people in this country who are eligible to get vaccinated who don't get vaccinated — that you have a significant pool of vulnerable people."

According to the Centers for Disease Control and Prevention, 70 percent of U.S.-based adults have been at least partially vaccinated for COVID-19. That figure is taking into consideration the U.S. as a whole; vaccination rates can vary considerably from one state to the next.

Some of the lowest vaccination rates are in deeply Republican states. The Mayo Clinic reports that the number of U.S. residents who have been at least partially vaccinated for COVID-19 ranges from 75 percent in Vermont and 72 percent in Massachusetts to 39 percent in Mississippi, 43 percent in Alabama and Mississippi and 49 percent in Missouri.

A major difference between the current COVID-19 surge that is pounding the U.S. and previous surges is that this one is, according to Biden's administration, a "pandemic of the unvaccinated."

Fauci told McClatchy, "Even if we vaccinated everyone today, we're not going to see an effect until the middle to end of September."

The more COVID-19 is allowed to spread in the U.S., according to Fauci, the more dangerous a variant that is worse than the Delta variant will be.

"If we don't crush the outbreak to the point of getting the overwhelming proportion of the population vaccinated," Fauci told McClatchy, "then what will happen is the virus will continue to smolder through the fall into the winter, giving it ample chance to get a variant — which, quite frankly, we're very lucky that the vaccines that we have now do very well against the variants, particularly against severe illness. We're very fortunate that that's the case. There could be a variant that's lingering out there that can push aside Delta."

Fauci added, "If another one comes along that has an equally high capability of transmitting but also, is much more severe, then we could really be in trouble. People who are not getting vaccinated mistakenly think it's only about them. But it isn't. It's about everybody else, also."