Variation of State-Issued Nonpharmaceutical Interventions During the Pandemic

The proportion of the US population subject to state-issued COVID-19 prevention measures varied greatly throughout the pandemic. During periods of high disease transmission and low coverage of state-issued measures, local or federal interventions may provide additional layers of protection if local or federal governments can issue prevention policies for their jurisdictions.

Research demonstrates that early, sustained, and layered implementation of nonpharmaceutical interventions (NPIs) is an essential strategy to mitigate burdens during pandemics. In the United States, state governments implemented NPIs, such as closure or social distancing requirements for restaurants and bars, stay-at-home orders, gathering limits, and mask mandates, to address the COVID-19 pandemic. The timing and stringency of these NPIs varied greatly from state to state, which raises the question, “how much of the US population was subject to these NPIs at various stages of the COVID-19 pandemic?” In our article, “Trends in percentages of the US population covered by state-issued COVID-19 nonpharmaceutical interventions, March 1, 2020–August 15, 2021,” we found that the coverage (relative to the US population) of state-issued NPIs varied considerably during the COVID-19 pandemic.

Most states quickly issued layered NPIs early in the COVID-19 pandemic. For instance, by March 20, 2020, 39 states and the District of Columbia prohibited on-premises dining at restaurants. The restrictions affected more than 80% of the US population. Also, between March 28 and May 28, 2020, more than 60% of the US population lived in states that allowed only gatherings of ten or fewer persons. The US population under stay-at-home mandates for all people ranged from 64% to 75% between April 3 and May 3, 2020.

As COVID-19 deaths began to decrease during the summer of 2020, most state-issued NPIs were eased or withdrawn. Yet, during winter 2020–2021, the US COVID-19 burden surged to maximums of around 250,000 daily new COVID-19 cases, and 3,400 deaths were reported, which exceeded the reported maximums of about 31,000 daily new COVID-19 cases and 2,300 deaths in early 2020. Despite the increase in cases and deaths, only a few states re-implemented NPIs.

States were more willing to continue or re-implement mask mandates and limits on gathering sizes than other NPIs. States started implementing mask mandates in April 2020 and most kept these mandates in place until March 2021. Around 80% of the US population was consistently covered by state-issued mask mandates between August 2020 and February 2021. Gathering restrictions limited to ten or fewer people also covered similar proportions of the US population in early 2020 (68%) and winter 2020–2021 (66%).

The US Food and Drug Administration first authorized the use of the Pfizer-BioNTech COVID-19 vaccine on December 11, 2020. All state-issued NPIs were lifted or relaxed as the fully-vaccinated population gradually increased and as COVID-19 caseloads decreased in the first half of 2021. However, most NPIs were not re-implemented when the Delta variant began spreading rapidly, and COVID-19 cases and deaths increased again between June and August 2021. During this time, no states prohibited indoor dining.

The sizable variations in the applicability of state-issued NPIs throughout the COVID-19 pandemic highlight the potential roles of city, county, or federal government action in a future pandemic. During periods of high disease transmission and low coverage of state-issued NPIs, other levels of government may reduce the pandemic burden by issuing additional layers of prevention policies for their respective jurisdictions.

For further information, read our article here: “Trends in percentages of the US population covered by state-issued COVID-19 nonpharmaceutical interventions, March 1, 2020–August 15, 2021.”

Data Sources:

Heesoo Joo, PhD, is an economist in the Division of Global Migration and Quarantine at the Centers for Disease Control and Prevention (CDC). She has evaluated public health programs and interventions and conducted regulatory impact analyses. Dr. Joo earned her PhD in Economics from the State University of New York at Albany.

Mara Howard-Williams, JD, is the lead of CDC’s Mitigation Policy Analysis Unit. She uses legal epidemiology to examine how the law impacts public health throughout the United States. Prior to joining CDC, she focused on the role of culture in global health, recognizing and adhering to international human rights instruments, and promoting health as a human right. Additionally, she helped global nonprofit organizations maximize their efforts through strategic program planning and evaluation.

Russell F. McCord, JD, is a public health analyst with the Office of Population Health and Policy Analytics (previously with PHLP). His work involves facilitating legal epi work with internal and external partners and providing subject matter expertise on legal and policy issues across various public health topics.

Gregory Sunshine, JD, serves as a Public Health Analyst with CDC’s Public Health Law Program in the Center for State, Tribal, Local, and Territorial Support. Gregory oversees research on emergency declarations, isolation and quarantine, medical countermeasures, and legal preparedness competencies. Gregory earned his JD from the University of Maryland School of Law and his Bachelor of Arts in Political Science from Dickinson College. Before CDC, Gregory worked at the Baltimore City Health Department.

James A. Fuller, PhD, is an epidemiologist in the Global Disease Detection Operations Center in the Center for Global Health at CDC. He specializes in data analysis and visualization during public health emergencies. James earned his PhD in Epidemiology from the University of Michigan School of Public Health.

Brian A. Maskery, PhD, currently works as an economist with CDC’s Division of Global Migration and Quarantine. Brian supports policy analysis and development and works on research topics including economic impact analyses, regulatory impact analyses, evaluation of prevention programs for migrating populations, and the economic costs of disease outbreaks and pandemics. Brian earned his PhD from the University of North Carolina School of Public Health and worked at the International Vaccine Institute prior to joining CDC.