{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T09:18:15Z","timestamp":1771665495216,"version":"3.50.1"},"reference-count":26,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2024,4,17]],"date-time":"2024-04-17T00:00:00Z","timestamp":1713312000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University of Southern California\u2019s Zumberge Innovation Fund"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>In the early phases of the COVID-19 pandemic, vaccine accessibility was limited, impacting large metropolitan areas such as Los Angeles County, which has over 10 million residents but only nine initial vaccination sites, which resulted in people experiencing long travel times to get vaccinated. We developed a mixed-integer linear model to optimize site selection, considering equitable access for vulnerable populations. Analyzing 277 zip codes between December 2020 and May 2021, our model incorporated factors such as car ownership, ethnic group disease vulnerability, and the Healthy Places Index, alongside travel times by car and public transit. Our optimized model significantly outperformed actual site allocations for all ethnic groups. We observed that White populations faced longer travel times, likely due to their residences being in more remote, less densely populated areas. Conversely, areas with higher Latino and Black populations, often closer to the city center, benefited from shorter travel times in our model. However, those without cars experienced greater disadvantages. While having many vaccination sites might improve access for those dependent on public transit, that advantage is diminished if people must search among many sites to find a location with available vaccines.<\/jats:p>","DOI":"10.3390\/ijerph21040491","type":"journal-article","created":{"date-parts":[[2024,4,17]],"date-time":"2024-04-17T10:52:37Z","timestamp":1713351157000},"page":"491","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Optimizing the Selection of Mass Vaccination Sites: Access and Equity Consideration"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-5225-3723","authenticated-orcid":false,"given":"Basim","family":"Aljohani","sequence":"first","affiliation":[{"name":"Department of Industrial and Systems Engineering, University of Florida, Gainesville, FL 32603, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Randolph","family":"Hall","sequence":"additional","affiliation":[{"name":"Epstein Department of Industrial and Systems Engineering, University of Southern California, Los Angeles, CA 90089, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,17]]},"reference":[{"key":"ref_1","unstructured":"Staff and Wire Reports (2023, June 05). List: SoCal Coronavirus Vaccination Super-Sites. Available online: https:\/\/www.nbclosangeles.com\/news\/local\/list-socal-super-coronavirus-vaccination-sites\/2506311\/."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ong, P.M., Pech, C., Gutierrez, N.R., and Mays, V.M. (2021). COVID-19 medical vulnerability indicators: A predictive, local data model for equity in public health decision making. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18094829"},{"key":"ref_3","unstructured":"Public Health Alliance of Southern California (2022, October 26). California Healthy Places Index. Available online: https:\/\/map.healthyplacesindex.org\/."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Yu, M., Fu, Y., and Liu, W. (2023). An Optimization Method for Equalizing the Spatial Accessibility of Medical Services in Guangzhou. ISPRS Int. J. Geo-Inf., 12.","DOI":"10.3390\/ijgi12070292"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Yinusa, A., and Faezipour, M. (2023). Optimizing Healthcare Delivery: A Model for Staffing, Patient Assignment, and Resource Allocation. Appl. Syst. Innov., 6.","DOI":"10.3390\/asi6050078"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Mollalo, A., and Tatar, M. (2021). Spatial Modeling of COVID-19 Vaccine Hesitancy in the United States. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18189488"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Alemdar, K.D., Kaya, \u00d6., \u00c7odur, M.Y., Campisi, T., and Tesoriere, G. (2021). Accessibility of Vaccination Centers in COVID-19 Outbreak Control: A GIS-Based Multi-Criteria Decision Making Approach. ISPRS Int. J. Geo-Inf., 10.","DOI":"10.3390\/ijgi10100708"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Cheng, M., Tao, L., Lian, Y., and Huang, W. (2021). Measuring Spatial Accessibility of Urban Medical Facilities: A Case Study in Changning District of Shanghai in China. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18189598"},{"key":"ref_9","unstructured":"Bravo, F., Hu, J., and Long, E. (2023). Closer to home: Partnering to distribute vaccinations under spatially heterogeneous demand. SSRN, preprint."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1007\/s10729-020-09538-w","article-title":"Selecting pharmacies for COVID-19 testing to ensure access","volume":"24","author":"Risanger","year":"2021","journal-title":"Health Care Manag. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1002\/nav.22007","article-title":"Where to locate COVID-19 mass vaccination facilities?","volume":"69","author":"Bertsimas","year":"2022","journal-title":"Nav. Res. Logist. (NLR)"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"811858","DOI":"10.3389\/fpubh.2022.811858","article-title":"A Survey of Location-Allocation of Points of Dispensing During Public Health Emergencies","volume":"10","author":"Alghanmi","year":"2022","journal-title":"Front. Public Health"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"240","DOI":"10.31387\/oscm0490344","article-title":"A Locational Analysis Model of the COVID-19 Vaccine Distribution","volume":"15","author":"Lusiantoro","year":"2022","journal-title":"Oper. Supply Chain. Manag. Int. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"102617","DOI":"10.1016\/j.omega.2022.102617","article-title":"Bi-objective optimization for a multi-period COVID-19 vaccination planning problem","volume":"110","author":"Tang","year":"2022","journal-title":"Omega"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e14151","DOI":"10.7717\/peerj.14151","article-title":"Optimal selection of COVID-19 vaccination sites in the Philippines at the municipal level","volume":"10","author":"Cabanilla","year":"2022","journal-title":"PeerJ"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Alhothali, A., Alwated, B., Faisal, K., Alshammari, S., Alotaibi, R., Alghanmi, N., Bamasag, O., and Bin Yamin, M. (2022). Location-Allocation Model to Improve the Distribution of COVID-19 Vaccine Centers in Jeddah City, Saudi Arabia. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19148755"},{"key":"ref_17","unstructured":"US Food & Drug Administration (2023, March 15). FDA Approves First COVID-19 Vaccine, Available online: https:\/\/www.fda.gov\/news-events\/press-announcements\/fda-approves-first-covid-19-vaccine."},{"key":"ref_18","unstructured":"US Census Bureau (2023, March 15). Explore Census Data, Available online: https:\/\/data.census.gov\/table?g=040XX00US06_1400000US06037101122_050XX00US06037."},{"key":"ref_19","unstructured":"US Census Bureau (2022, December 01). Explore Census Data, Available online: https:\/\/data.census.gov\/map?g=040XX00US06&tid=ACSDP5Y2020.DP04&cid=DP04_0057E&layer=VT_2020_860_Z2_PY_D1&mode=thematic&loc=33.5590."},{"key":"ref_20","unstructured":"Centers for Disease Control and Prevention (2023, August 15). Coronavirus Disease 2019 (COVID-19), Available online: https:\/\/archive.cdc.gov\/#\/details?q=race&start=0&rows=10&url=https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/covid-data\/investigations-discovery\/hospitalization-death-by-race-ethnicity.html."},{"key":"ref_21","unstructured":"Los Angeles County Department of Public Health (2023, May 13). LA County COVID-19 Vaccine Dashboard, Available online: https:\/\/publichealth.lacounty.gov\/media\/Coronavirus\/vaccine\/vaccine-dashboard.htm."},{"key":"ref_22","unstructured":"U.S Bureau of Labor Statistics (2023, December 05). Los Angeles Area Economic Summary, Available online: https:\/\/www.bls.gov\/regions\/west\/summary\/blssummary_losangeles.pdf."},{"key":"ref_23","unstructured":"US Department of Transportation (2023, May 08). Revised Departmental Guidance on Valuation of Travel Time in Economic Analysis, Available online: https:\/\/www.transportation.gov\/office-policy\/transportation-policy\/revised-departmental-guidance-valuation-travel-time-economic."},{"key":"ref_24","unstructured":"AAA Southern California (2023, May 10). Auto Club: SoCal Driving Costs Six Percent Higher than US Average. Available online: https:\/\/news.aaa-calif.com\/news\/auto-club:-socal-driving-costs-six-percent-higher-than-us-average."},{"key":"ref_25","unstructured":"City of Los Angeles (2022, November 20). City of Los Angeles Hub. Available online: https:\/\/geohub.lacity.org\/."},{"key":"ref_26","unstructured":"Office of Policy Development and Research (2023, November 20). ZIP Code Population Weighted Centriods. Available online: https:\/\/hudgis-hud.opendata.arcgis.com\/datasets\/d032efff520b4bf0aa620a54a477c70e_0\/about."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/21\/4\/491\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:29:34Z","timestamp":1760106574000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/21\/4\/491"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,17]]},"references-count":26,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["ijerph21040491"],"URL":"https:\/\/doi.org\/10.3390\/ijerph21040491","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,17]]}}}