Many areas in the United States can expect to see new surges in Covid cases thanks to lagging vaccination rates and an increase in cases of the more transmissible and dangerous delta variant, according to Dr. Anthony Fauci.
Areas including the Southeast and Midwest, where there are lower vaccination rates, are the most vulnerable — and it could necessitate safety measures, such as wearing a mask again.
"[I]n some places, some states, some cities, some areas, where the level of vaccination is low and the level of virus dissemination is high, that's where you're going to see the spikes," Fauci, White House chief medical advisor, told Chuck Todd during an interview with NBC's "Meet the Press" on Sunday.
"We have a big country with disparity in the willingness to be vaccinated," Fauci said. While 67% of adults in the United States overall have received at least one dose of a Covid vaccine, "there are some states where the level of vaccination of individuals is 35% or less," he said.
Currently, the states with the lowest vaccination rates include Mississippi (30% of people vaccinated), Alabama (33%), Wyoming (35%) and Arkansas (34%), according to Our World in Data.
Some areas are already seeing the effects of low vaccination rates. Recent data from Johns Hopkins University shows that states where vaccination rates are lagging have almost three times as many new Covid cases compared to states with high vaccination rates, CNN reported Monday.
Arkansas, for example, where the vaccination rate is 34%, has 17 new daily cases per 100,000 people, versus Vermont, the nation's most vaccinated state at 66% vaccinated, which has only 0.4 cases per 100,000.
Additionally, unvaccinated people are even more at risk due to the delta variant, which is "faster, it is fitter [and] it will pick off the more vulnerable more efficiently than previous variants," Dr. Mike Ryan, executive director of the WHO's health emergencies program, said during a news conference on June 21.
The potential for new surges means that in these environments where there is a high level of virus and a low level of vaccination, there is "good reason" to follow extra safety precautions, such as wearing a mask even if you're vaccinated, Fauci said.
In May, the CDC said that fully vaccinated people can stop wearing masks and social distancing indoors and outdoors.
But local governments that are responsible for determining what restrictions, such as mask mandates, are appropriate given the level of spread and vaccination rate in a community. For instance, due to a rise in Covid cases attributed to the delta variant, public health officials in Los Angeles County recommended on June 28 that everyone, including vaccinated individuals, wear masks indoors in public places.
It is unlikely, however, that there will be a nationwide spike like the U.S. witnessed last fall and winter, given the proportion of people who are now vaccinated, Fauci said. The nation's average fully vaccinated rate is 47%.
Fauci has said that the inconsistency in vaccination rates across the country will lead to "two Americas," that is, one where the risk of Covid spikes is high and another where the majority of people are vaccinated and the risk is low.
Eric Topol, founder and director of the Scripps Research Translational Institute predicted that the U.S. will see "this patchwork phenomenon," he told Scientific American. "Certain places will light up, and hopefully they won't light up too badly."
While geographic pockets with high rates of vaccination might be safe, Dr. F. Perry Wilson, an epidemiologist at Yale Medicine, said that it could be possible for the virus to "hop, skip, and jump from one poorly vaccinated area to another," leading to "hyperlocal" outbreaks, in an interview with Yale Medicine.
"As we've said so often, that vaccines are not, even as good as they are and highly effective, nothing is 100%," Fauci said.
Correction: This story has been corrected to reflect that the delta Covid variant is more transmissible and more dangerous.