SALT LAKE CITY (ABC4) – Two Utah counties have seen an improvement in their COVID-19 community transmission rates over the last week while two have seen a worsening transmission rate. Based on these rates, the Centers for Disease Control and Prevention is advising Utahns to wear masks in 27 counties.

Last week, nearly every Utah county was marked as having a high level of community transmission of the virus, based on the CDC’s tracking. Of Utah’s 29 counties, Rich and Morgan were the only last week to not be in the ‘high’ category.

In July, the CDC issued new masking guidelines for everyone, regardless of vaccination status, in response to the Delta variant spreading rapidly. Within the guidelines, the CDC encourages anyone living in areas of “substantial and high” virus transmission to wear a mask inside.

According to the CDC’s COVID Data Tracker, the vast majority of counties – 3,020 – across the U.S. are seeing substantial or high COVID-19 transmission. Nebraska is the only state which appears not overwhelmed by red or orange counties.

Below is a side-by-side comparison of the COVID Data Tracker. On the left, is the map for the week of Monday, August 16, through Sunday, August 22. On the right, the map for the week of Sunday, August 22 through Saturday, August 28.

Utah is again among the states who are vastly red.

Of Utah’s 29 counties, just two are not in the ‘high’ categories – Sanpete and Piute, which are in the moderate and low categories, respectively. In the previous week, Rich and Morgan counties were in the moderate and substantial categories, respectively. This week, both are in the high category.

Based on the latest CDC guidance, this means everyone, vaccinated or not, should be wearing a mask when indoors in all but two counties. Below is a side-by-side comparison of Utah’s COVID-19 transmission rates, courtesy of the CDC. On the left, Utah’s transmission rate for Aug. 24, and on the right, the map as of Aug. 30.

As of Aug. 30, 60.4% of Utahns 12-years-old and older are fully vaccinated against the virus. The vaccine is not currently available for kids 11 and under. For more on COVID-19 in Utah, click here.