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COVID-19 Data Modernization

COVID-19 Data Modernization
Updated Mar. 31, 2023
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Interpretive Summary for March 31, 2023

COVID-19 Data Modernization

Intro - 03-31-2023

This is part of a series of Weekly Review issues coinciding with the end of the COVID-19 public health emergencyExternal and what it means for CDC and the data we report. The first issue published on February 24, 2023, and the final two issues will publish on April 14 and May 12.

The COVID-19 pandemic fundamentally changed expectations for public health, especially the speed at which credible health information is delivered. It created an opportunity to further transform how we collect, use, and share data at CDC and beyond. That momentum won’t stop when the public health emergency ends on May 11. CDC will continue tracking and reporting COVID-19 data, with some changes, while improving our readiness for the next public health emergency.

The Data Modernization Initiative (DMI) is our solution to the challenges public health has faced for too long, which have been highlighted during the pandemic. Through the initiative, CDC is creating a world in which data can move faster than disease. Our ultimate goal is to get better, faster, actionable data for decision-making at all levels of public health.

The pandemic underscored the importance of good data across the nation’s public health system. CDC is working to advance eight core goals Pdf[240 KB, 1 page] for public health surveillance of COVID-19:

  • Monitor trends and intensity of SARS-CoV-2 transmission, identify outbreaks, and provide data to initiate case and contact investigations
  • Understand disease severity and the spectrum of illness
  • Monitor and track vaccine distribution, uptake, and effectiveness
  • Describe risk factors for severe disease and transmission
  • Monitor for variants
  • Assess impact on healthcare systems
  • Estimate disease burden, and forecast trends, impact, and clinical and public health needs
  • Monitor impact of disease and interventions on health equity

DMI’s vision is to create one public health community that can engage robustly with healthcare, communicate meaningfully with the public, improve health equity, and have the means to protect and promote health. The gains we’ve made during the pandemic are now building a bridge to a new kind of surveillance and better approaches to public health data.

What’s New:

  • The Vaccine Effectiveness page was updated to highlight vaccine effectiveness studies published from October 2022 to February 2023.
  • The new Links to Archived Data and Visualizations page is now live to the public. This new page lists all pages archived from COVID Data Tracker and where the archived information can be found.

COVID-19 Community Levels*

As of March 30, 2023, there are 25 (0.8%) counties, districts, or territories with a high COVID-19 Community Level, 279 (8.7%) with a medium Community Level, and 2,915 (90.5%) with a low Community Level. Compared with last week, the number of counties, districts, or territories in the high level decreased by 0.1%, the medium level increased by 2.8%, and in the low level decreased by 2.7%. Overall, 35 out of 52 jurisdictions** had high- or medium-level counties this week. California, Connecticut, Delaware, District of Columbia, Kentucky, Maine, Maryland, Massachusetts, Nevada, New Jersey, North Carolina, Oregon, Puerto Rico, Rhode Island, South Carolina, Utah, and Washington are the jurisdictions that have all counties at low Community Levels.

To check your COVID-19 Community Level, visit COVID Data Tracker. To learn which prevention measures are recommended based on your COVID-19 Community Level, visit COVID-19 Community Level and COVID-19 Prevention.

*CDC recommends use of COVID-19 Community Levels to determine the impact of COVID-19 on communities and to take action. CDC also provides Community Transmission Levels to describe the amount of COVID-19 spread within each county. Healthcare facilities use Community Transmission Levels to determine infection control interventions.

**Includes the 50 states, the District of Columbia, and Puerto Rico.

U.S. COVID-19 Community Levels by County

covid community levels USA map green is low, yellow is medium, orange is high, grey is no data

Reported Cases

As of March 29, 2023, the current 7-day average of weekly new cases (19,999) decreased 9.2% compared with the previous 7-day average (22,035). A total of 104,137,196 COVID-19 cases have been reported in the United States as of March 29, 2023.

Total Cases Reported

Current 7-Day Average*

Previous 7-Day Average

Change in 7-Day Average since Previous Period

*Historical cases are excluded from weekly new cases and 7-day average calculations until they are incorporated into the dataset for the applicable date. Of 79,780 historical cases reported retroactively, 5,347 were reported in the current week and 18,232 in the prior week.

Weekly Trends in COVID-19 Cases in the United States Reported to CDC

Weekly trends in COVID-19 cases in the United States reported to CDC

COVID-19 Variants

CDC Nowcast projections* for the week ending April 1, 2023, estimate the proportion of these lineages designated as Omicron with estimates above 1%: XBB.1.5, XBB.1.9.1, XBB, XBB.1.5.1, and BQ.1.1.

XBB.1.5 is projected to be at approximately 87.9% (95% PI 85.0-90.4%).

XBB.1.9.1, XBB, XBB.1.5.1, and BQ.1.1 are projected to be between 1.9% and 4.6% of circulating lineages.

XBB.1.5 has reached saturation, and XBB.1.9.1, XBB, and XBB.1.5.1 all have positive growth. All other virus lineages are predicted to have very slow or no growth in proportion.

See COVID Data Tracker for the proportions of all relevant lineages currently circulating.

*CDC uses Nowcast projections to predict current variant proportions circulating in the United States. The median time from specimen collection to sequence data reporting is about 3 weeks. As a result, weighted estimates for the most recent few weeks may be unstable or unavailable. View Nowcast estimates on CDC’s COVID Data Tracker website on the Variant Proportions page. 

Variant Proportions

Nowcast variant proportion estimates for 3/26/2023 - 4/1/2023 by HHS Region


As of March 29, 2023, 674.0 million vaccine doses have been administered in the United States. Overall, about 230.4 million people, or 69.4% of the total U.S. population, have completed a primary series.* About 54.9 million people, or 16.5% of the U.S. population, have received an updated booster dose.

Vaccine Doses Administered

Updated Booster Doses Administered**

People who have completed a primary series* (69.4% of the U.S. population)

People who have received an updated booster (16.5% of the eligible U.S. population)

Percentage point change from last week

Percentage point change from last week

*Represents the number of people who have received the second dose in a two-dose COVID-19 vaccine series (such as the Pfizer-BioNTech, Moderna, or Novavax vaccines) or one dose of the single-shot Johnson & Johnson’s Janssen vaccine.

**The number of updated booster doses administered is larger than the number of people who have received an updated booster because one person may receive more than one booster dose.

Daily Change in the Total Number of Administered COVID-19 Vaccine Doses Reported to CDC by the Date of Administration, United States

red line

7-Day moving average

Daily count of COVID-19 vaccination doses by date of vaccine administration, United States

COVID-19 Updated Booster Dose Administration, United States

COVID-19 updated (bivalent) booster dose administration in the United States, by age booster legend


New Hospital Admissions

The current 7-day daily average for March 22–28, 2023, was 2,370. This is a 5.3% decrease from the prior 7-day average (2,501) from March 15–21, 2023.

Total New Admissions

Current 7-Day Average

Prior 7-Day Average

Change in 7-Day Average

The start of consistent reporting of hospital admissions data was August 1, 2020.

Daily Trends in Number of New COVID-19 Hospital Admissions in the United States

Daily Trends in Number of New COVID-19 Hospital Admissions in the United States

New admissions are pulled from a 10 am EDT snapshot of the HHS Unified Hospital Data – Analytic Dataset. Due to potential reporting delays, data from the most recent 7 days, as noted in the figure above with the grey bar, should be interpreted with caution. Small shifts in historic data may also occur due to changes in the Centers for Medicare & Medicaid Services (CMS) Provider of Services file, which is used to identify the cohort of included hospitals.

COVID-NET: Trends in COVID-19 Hospitalization Rates Among Adults and Children (All Ages)

CDC’s Coronavirus Disease 2019-Associated Hospitalization Surveillance Network (COVID-NET) shows that overall COVID-19-associated hospitalizations have continued to decline since late December 2022. Hospitalization rates among people of all ages have declined from a peak of 11.6 per 100,000 population for the week ending December 31, 2022, and have remained below 7.0 per 100,000 population since the week ending January 28, 2023.

Weekly Rates of COVID-19-Associated Hospitalizations Among Adults and Children (All Ages)

COVID-NET chart - 03-31-2023 covid-net chart legend

The dashed lines for the current season indicate potential reporting delays and interpretation of trends should exclude data from recent weeks. Coronavirus Disease 2019 (COVID-19)-Associate­­d Hospitalization Surveillance Network (COVID-NET), a RESP-NET platform, is an additional source for hospitalization data collected through a network of more than 250 acute-care hospitals in 13 states (representing ~10% of the U.S. population). Detailed data on patient demographics, including race and ethnicity, underlying medical conditions, medical interventions, and clinical outcomes, are collected using a standardized case reporting form.



The current 7-day average of new deaths (228) decreased 29.4% compared with the previous 7-day average (323). As of March 29, 2023, a total of 1,125,366 COVID-19 deaths have been reported in the United States.

Total Deaths Reported

Current 7-Day Average*

Prior 7-Day Average

Change in 7-Day Average Since Prior Period

*Historical deaths are excluded from the weekly new deaths and 7-day average calculations until they are incorporated into the dataset by their applicable date. Of 4,113 historical deaths reported retroactively, none were reported in the current week and none were reported in the prior week.

Weekly Trends in Number of COVID-19 Deaths in the United States Reported to CDC

Weekly trends in number of COVID-19 deaths in the United States reported to CDC More Death Data


The percentage of COVID-19 NAATs (nucleic acid amplification tests)* that are positive is decreasing in comparison to the previous week. The 7-day average of percent positivity from NAATs is now 7.1%. The 7-day average number of tests reported for March 17–23, 2023, was 192,093, down 22.0% from 246,346 for the prior 7 days.

Total Tests Reported

7-Day Average Tests Reported

7-Day Average % Positivity

Previous 7-Day Average % Positivity

Percentage point change in 7-Day Average % Positivity since Prior Week

*Test for SARS-CoV-2, the virus that causes COVID-19

COVID-19 NAAT Laboratory Test 7-day Percent Positivity by State/Territory

COVID-19 nucleic acid amplification test 7-day percent positivity by state and territory

Wastewater Surveillance

COVID Data Tracker’s Wastewater Surveillance tab tracks levels, changes, and detections of SARS-CoV-2* viral RNA in wastewater at over 1,400 testing sites across the country.

Currently, about 43% of sites across the country are reporting moderate to high SARS-CoV-2 levels in wastewater. About 11% of sites reporting wastewater data are currently seeing some of the highest levels for those sites since December 1, 2021. About 42% of sites are experiencing a decrease in SARS-CoV-2 levels, and about 51% are reporting an increase.

For more information on how to use wastewater data, visit CDC’s wastewater surveillance website.

*The virus that causes COVID-19

SARS-CoV-2 Levels in Wastewater by Site

SARS-CoV-2 levels in wastewater by site white dot new site, blue dot 0% to 19%, light blue dot 20% to 39%, lightest blue dot 40% to 59%, orange dot 60% to 79%, red dot 80% to 100%

0% denotes that levels are the lowest they have been at the site; 100% denotes that levels are the highest they have been at the site.

More Wastewater Data