After four straight days of reporting 1,000 or more new COVID-19 cases, Arizona health officials are reporting 980 new cases on Sunday.

The four-day stretch of 1,000-plus cases is the longest since March 2 through 7, according to Arizona health officials.

The number of virus-related hospitalizations rose in the past week, with 745 COVID-19-related hospitalizations as of Friday.

Health experts attribute the recent surge to low vaccination rates, the fast-spreading delta variant and Fourth of July gatherings.

Nearly 51% of Arizonans have received one dose of a vaccine, which experts say will help prevent considerable strain on the state’s health care system.