Understanding COVID-19 in TK-12 Schools in Los Angeles County

  • Vaccines continue to offer effective protection against COVID-19. Unvaccinated children and youth continue to have higher case rates than those who are vaccinated in their same age groups. As of January 11, 2024, the 90-day rate of COVID-19 among youth aged 12-17 years in Los Angeles County was 1.9 times higher among those who were unvaccinated compared to those who were fully vaccinated.
  • School prevention strategies reduce transmission. Evidence has shown that a multipronged prevention strategy that includes masking, physical distancing, testing, isolation of identified cases and quarantining of exposed individuals, and vaccination can help to reduce COVID-19 transmission on campus. (See COVID-19 Case Rates in TK-12 School and in the Community, Los Angeles County)
  • Data dashboards are transparent and actionable. The TK-12 School Data dashboard provides dynamic, visual information to learn about the status of COVID-19 clusters in schools. This information can assist districts and schools to strengthen and target their COVID-19 prevention measures to ensure that schools remain a safe environment for students, teachers, and staff.


  • A cluster is defined as 3 or more COVID-19 cases among students, teachers, and/or staff within a classroom, office, or other pre-defined or identifiable group who were on campus at any point within the 7 days prior to illness onset date. COVID-19 clusters are reported to Public Health from TK-12 Schools and Youth Programs and may have epidemiological links. Clusters do not necessarily represent outbreaks. Public Health investigates these reported clusters and confirms epidemiological linkages to determine if the outbreak criteria have been met.
  • Cases include laboratory confirmed cases and unconfirmed cases (e.g., positive results from over the counter or at-home tests) reported to Public Health.
  • Data may differ from information managed at the district- or school-level due to the reporting time period and data quality control conducted by Public Health staff.
  • Data are refreshed the last Wednesday of every month and reflect data from Monday to Sunday from the prior week. Due to updates and reporting delays, counts may change in future reports.
  • If you have any questions, please contact communityoutbreak@ph.lacounty.gov.


COVID-19 Clusters in TK-12 Schools

New COVID-19 Clusters Reported in the Past 7 Days by TK-12 Schools and Programs, with COVID-19 Community Vaccination or Case Rates, 18 Mar 2024 - 24 Mar 2024

Zero clusters were reported in the past 7 days.

+−
COVID-19 Community Case Rate
Per 100,000 Persons
No Data
0 - 0.49
0.5 - 0.99
1.0 - 1.49
>= 1.5
Leaflet | © OpenStreetMap contributors © CARTO
  • TK-12 schools are required to report all clusters of 3 or more COVID-19 cases who were on campus within 7 days of their illness onset date to Public Health.
  • Schools with a cluster of 3 or more new cases in the past 7 days do not reflect school outbreaks unless posted in the outbreak table below.
  • Cluster associated cases may include individuals who reside outside of Los Angeles County but attend, are employed by, or visited a school/program in Los Angeles County.
  • Community COVID-19 case rates by school district are calculated as the 7-day average number of COVID-19 cases residing within a Los Angeles County school district boundary divided by the population residing within the school district boundary per 100,000 persons. Residence is based on reported home address.
  • Community vaccination by school district is calculated as the percentage of vaccine eligible children aged 5-11 years and 12-18 years who resided within a Los Angeles County school district boundary based on their reported home address and have been vaccinated with all recommended COVID-19 vaccines according to CDC guidelines based on their age and previous vaccination record.
  • Data reported on COVID-19 clusters and cluster associated cases may differ from the information managed at the district- or school-level due to the reporting time period and additional quality control conducted by Public Health staff.
  • Pasadena and Long Beach cases are reported directly to their local health departments.


COVID-19 Outbreaks in TK-12 Schools

A COVID-19 outbreak in TK-12 schools or programs serving school-aged children is when there are at least 3 or more laboratory-confirmed cases of COVID-19 within a 7-day period of each other in a specific group with members who are epidemiologically-linked, do not share a household, and are not a close contact of each other outside of the school. A small fraction of the 3000 schools in LA County have outbreaks. When an outbreak does occur, Public Health assists schools with mitigation measures.

For a list of active COVID-19 outbreaks in TK-12 schools and other educational settings, please see the Active Outbreaks tab.

  • Epidemiologically-linked means that the cases were present at some point in the same setting during the same time while infectious.
  • Outbreaks that are active means that there has been at least one COVID-19 case that is epidemiologically-linked to the outbreak cluster within the past 7 days.