DENVER (KDVR) — A surge in COVID-19 cases fueled by the highly infectious Delta variant is spurring a new round of public health measures aimed at limiting another wave of infections. Public health data shows the surge is particularly strong in states with lower vaccination rates.

Nationally, COVID-19 rates have swung upward since bottoming out at the summer solstice, forcing the Centers for Disease Control and Prevention to revisit mask use guidelines, even for the previously vaccinated.

On June 21, the 7-day average for new cases was 11,609 per day — its lowest point since the pandemic began. Only a month later on July 23, that daily average had quadrupled to 47,683 per day, which is roughly the same as the national daily case average in the first week of May.

Altogether, the nation’s states added 856,897 COVID-19 cases between June 21 and July 25. But a handful of states claim most of those new cases.

Half of the U.S. COVID cases added in the last month come from only five states: Florida, Texas, California, Missouri and Louisiana.

Florida alone accounts for 20% of the summer’s COVID-19 cases with 163,737 — roughly twice as many as Texas, the state with the next-highest total. Texas added 89,286, or 10% of the total summer COVID cases since June 21. California added roughly the same amount, with 83,899.

However, pinning the surge on the nation’s most populous states is only part of the story. The mid-sized states of Missouri and Louisiana added 52,585 and 35,197 cases, respectively.

Generally, a map of vaccine rates and a map of current COVID-19 rates have an inverse relationship: Heavily vaccinated states have low COVID rates, and vice versa. Gulf Coast states and Southern states are seeing some of the nation’s higher COVID rates and lower vaccination rates.

The first chart below depicts high per-capita vaccination rates with darker shades, while the second shows high infection rates in darker tones.

In recent days, governors have gone one record to pin blame for the surge on the vaccine-hesitant.

“An individual’s choice not to get vaccinated is now impacting the rest of us in a profound and devastating and deadly way,” California Governor Gavin Newsom said in statements to the press earlier this week.

The Associated Press reports that Newsom has been publicly blaming “right wing” politicians and media for perpetuating misinformation about the safety and necessity of the vaccines.

AP polling done in conjunction with the Center for Public Affairs Research recently found that 43% of Republicans said they had not been vaccinated or definitely wouldn’t be, compared to 10% of Democrats. But those findings were made before some news personalities and other high-profile Republican figures voiced a more supportive tone toward the vaccine effort last week.

Last Thursday, Republican Governor Kay Ivey, of Alabama, left no ambiguity her position.

“The new cases of COVID are because of unvaccinated folks,” Gov. Ivey said during an event in Birmingham Thursday. “Almost 100% of the new hospitalizations are with unvaccinated folks. And the deaths are certainly occurring with the unvaccinated folks. These folks are choosing a horrible lifestyle of self-inflicted pain.”

The CDC had previously indicated that vaccinated Americans need not wear masks, even in crowded indoor spaces. The agency reversed course on that guidance on Tuesday, recommending that fully vaccinated Americans in areas with “substantial and high” transmission rates should wear masks indoors at public spaces.