▶ Watch Video: U.S. sees a rise in new coronavirus infections due to the Delta variant Washington — Dr. Anthony Fauci, chief medical adviser to President Biden, said Sunday that Americans who remain unvaccinated against the coronavirus are “propagating” the latest outbreak of cases of the highly contagious Delta variant. “We have 100 million people in this country … who are eligible to be vaccinated, who are not vaccinated,” Fauci said in an interview with “Face the Nation.” “We’ve really got to get those people to change their minds, make it easy for them, convince them, do something to get them to be vaccinated because they are the ones that are propagating this outbreak.” Transcript: Dr. Anthony Fauci on “Face the Nation” Coronavirus infections, hospitalizations and deaths have risen across the country, with the Delta variant driving the surge in areas with low vaccination rates. Nearly all patients hospitalized with COVID-19 are unvaccinated, with the vaccines continuing to provide strong protection against severe illness. Amid the spike in cases, the Centers for Disease Control and Prevention (CDC) last week updated its mask guidance, recommending both vaccinated and unvaccinated Americans in areas of the country with “substantial or high transmission” of COVID-19 return to wearing masks indoors. On Friday, the CDC released more details about what led to the shift, citing new data from a Delta variant outbreak in Provincetown, Massachusetts. The report found that fully vaccinated people with so-called breakthrough infections of the Delta variant can spread the virus, and they carried roughly the same amount of virus in their nasopharynx as the unvaccinated. But the report also showed the coronavirus vaccines protected against serious illness and death. Of the 469 COVID-19 cases identified in the study, 346 were among fully vaccinated people. But no deaths were reported, and of the four fully vaccinated people who were hospitalized, two had underlying medical conditions. Fauci, director of the National Institute of Allergy and Infectious Diseases, said Sunday that the study “absolutely” shows that vaccines work, and said it’s “understandable” that it produced dual messages. The “predominant message,” he said, is that “if you’re vaccinated, you’re much, much more protected against getting infected than an unvaccinated who is completely vulnerable.” “If you do get infected, the likelihood of your getting a severe outcome of the infection is very low,” Fauci continued. “It is much more likely that you will be either without symptoms or minimally symptomatic. So the vaccine is doing what you want it to do. It’s protecting people from getting sick.” Fauci said breakthrough infections are expected, since no vaccine is 100% effective, but said those who are vaccinated and become infected with the coronavirus experience either minimal symptoms or no symptoms at all. A study released Friday from the Kaiser Family Foundation found the rate of breakthrough cases reported among the fully vaccinated is less than 1% in states that provide such data. Now that federal health officials know those with breakthrough infections can transmit the Delta variant, Fauci said the “fundamental reason” for the change in the CDC’s mask guidance is to ensure the virus is not spread to the vulnerable or elderly, as well as children who are not yet eligible for the coronavirus vaccines. “One of the issues that just looms large … when you’re dealing with this, is that you understand people’s feeling that they have the individual right to make their own decision. And I respect that, for sure,” Fauci said. “But the issue is, if you’re going to be part of the transmission chain to someone else, then your decision is impacting someone else. It’s not only impacting you. And you’ve got to think about it, that you are a member of society and you have a responsibility.” Efforts to push the unvaccinated to get their shots do appear to be working, Fauci said. The CDC reported an uptick in coronavirus vaccines administered last week, including in areas with lower rates. Of the doses administered Friday, 563,000 were in newly vaccinated individuals, the highest since July 1, according to Cyrus Shahpar, the White House’s COVID-19 data director.