A new report from the Centers for Disease Control and Prevention examines how effective Arizona’s mitigation measures were on stopping the increase of COVID-19. The report, which tracked case numbers from Jan. 22 to Aug. 7, shows a clear correlation in reduced virus cases after face masks and social distancing were mandated.

In Arizona, the average number of daily virus cases increased approximately 151% after the statewide stay-at-home order was lifted in mid-May, with Gov. Doug Ducey declaring “we are clearly on the other side of this pandemic.”

According to CDC data, two weeks after Arizona's stay-at-home orders were first lifted on May 15, daily new COVID cases increased from 808 on June 1 to 2,026 on June 15. This led to a peak in cases from June 29 to July 2. Cases then began to reduce after Ducey allowed local officials to implement their own mandates on June 17. The ensuing local policies were applicable to approximately 85% of the total Arizona population.

COVID-19 cases then declined by approximately 75% following "sustained prevention efforts" across Arizona. These prevention efforts include wearing masks, limiting public events and closing certain businesses such as bars, movie theaters and gyms. Due to the infection cycle of the virus, case increases and reductions are delayed by an average of two weeks after mandates change.

The report states: The number of COVID-19 cases in Arizona stabilized and then decreased after sustained implementation and enforcement of statewide and locally enhanced mitigation measures, beginning approximately two weeks after implementation and enforcement of mask mandates and enhanced sanitation practices began on June 17; further decreases were observed during July 13–August 7, after statewide limitations and closures of certain services and businesses.

The CDC continues by saying that quantitative data on the effectiveness of community mitigation measures at suppressing the virus’ spread is difficult to calculate, and the primary goal of implementing these widespread “enhanced mitigation measures” in Arizona was to protect and save lives and maintain capacity in the health care system. Ultimately, a combination of voluntary and enforceable measures is more effective than any single measure, although public policy can effectively increase social distancing.

These mitigation measures should still be implemented, particularly before a vaccine or other treatments become widely available. State, local and tribal officials are best positioned to continually monitor data and collaborate to determine the level and types of enhanced mitigation required. Mitigation measures, including mask mandates, that are implemented and enforced statewide appear to have been effective in decreasing the spread of COVID-19 in Arizona.