Many COVID-19 restrictions have been lifted, mask mandates have eased and the country's economy has mostly reopened. However, renewed hopes of normalcy may be cut short by the more transmissible and deadly delta variant.

This fitter virus poses a particular threat to vulnerable areas like the Southeast and Midwest, where vaccination levels are lower and people are more vulnerable. This potential new surge could bring back “good reason” to follow extra safety precautions, such as wearing a mask even if you are vaccinated, according to Dr. Anthony Fauci.

Approximately 1,000 counties have vaccination coverage of less than 30%. Many of those areas with low vaccination rates can expect to see new surges in COVID cases, according to Fauci.

″[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 said Sunday on NBC’s "Meet the Press."

While 67% of adults have received at least one dose of the vaccine, Fauci noted that "there are some states where the level of vaccination of individuals is 35% or less."

The states with the lowest vaccination rates are Mississippi (30%), followed by Alabama (33%), Wyoming (35%) and Arkansas (34%), according to Our World in Data.

Vaccination disparities are already impacting people. Data from Johns Hopkins University shows that states with lagging vaccination rates have almost three times as many new cases compared to those with high vaccination rates.

Some places, like Los Angeles County, are already reinstating mask mandates as preventative measures to protect the unvaccinated population and avoid a new outbreak.

This is unlikely to be a nationwide spike. The delta variant is expected to be a pandemic among the unvaccinated as they are more vulnerable to the virus.

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.

Fauci recently appeared on PBS NewsHour to explain the threat of the delta variant.

"It is clearly more transmissible by multifold, a few times more," he said. "And if you look at the hospitalization, there was a study from Scotland which showed that hospitalizations clearly had a few times more likelihood of getting hospitalized if you were infected with the Delta variant vs. the variants that were previously circulating."