INDIANAPOLIS (AP) — The number of Indiana counties approaching high risk for community spread of COVID-19 nearly quadrupled in one week as an especially contagious coronavirus variant spread throughout the state.

Republican Gov. Eric Holcomb cited Indiana’s increased levels of COVID-19 infections as he issued an extension Thursday of the statewide public health emergency until Aug. 30. A new executive order from Holcomb, however, does not reimpose any statewide face mask requirements or crowd-size limits that expired in April.

As of Monday, 15 counties were in Indiana’s second-riskiest category for the spread of the disease, including Huntington, DeKalb, and Steuben, according to an update posted Wednesday on the state’s coronavirus dashboard. Four counties were in that orange category one week earlier.

Indiana’s color-coded coronavirus risk map shows blue, yellow, orange, and red levels that measure weekly COVID-19 cases per 100,000 county residents and the 7-day positivity rate. No Indiana counties are in the highest-risk red category, which indicates very high community spread.

The state’s new coronavirus cases and hospitalizations for COVID-19 rebounded this month to levels last seen in May, as the delta variant, which spreads more easily than previous versions of the coronavirus, continues spreading throughout the country, particularly in places with low vaccination rates, such as Indiana.

Tests conducted this month on a sample of Indiana’s cases showed that as of Thursday, nearly 92% of them were the delta variant, the dashboard showed.

Holcomb said this week that he’s concerned about the variant’s spread at a time when just 50% of Indiana’s eligible population — those age 12 and up — is fully vaccinated and the weekly numbers of Hoosiers getting vaccinated continues to decline after peaking in April.

“If this isn’t persuasive to get vaccinated, I don’t know what could be,” he said Tuesday. “This is not hard to understand. Vaccines work. Look at the numbers. Look at the cases. Look at the hospitalization rates. Look at the deaths. It’s overwhelmingly the unvaccinated.”

Only 44% of Indiana’s full population, including children younger than 12 who aren’t eligible, is fully vaccinated against the virus. That lags behind the national average of 49.4% and far behind the state with the highest vaccination rate, Vermont, where more than two-thirds of the population — 67.4% — is inoculated.

Holcomb said Tuesday that he still won’t implement any new statewide restrictions and will leave such decisions to local officials. The state’s health commissioner, Dr. Kristina Box, is scheduled to provide an update Friday on the state’s response to the pandemic.