An effective volunteer community-based COVID-19 response program: the Vashon, WA Medical Reserve Corp Experience

Background Vashon, WA is a rural community at risk from COVID-19 due to advanced age and limited access to acute care. Medical Reserve Corps are a national network of 800 volunteer healthcare organizations that have contributed to the pandemic response in many communities. Here we evaluate the effectiveness of the Vashon Medical Reserve Corp’s (VMRC) volunteer, community-based COVID-19 response program that integrated public engagement, SARS-CoV2 testing, contact tracing, vaccination and material support in reducing COVID-19 transmission and severe disease. Methods This observational cross-sectional study compares cumulative COVID-19 case, hospitalization and death rates on Vashon with other King County zip codes and the county at large from February 2020 through November 2021. We developed multiple linear regression models of COVID-19 rates using metrics of age, race/ethnicity, wealth and educational attainment across King County zip codes. Effectiveness of contact tracing was evaluated by timeliness and success of case investigations, and identification and testing of named contacts. Vaccination effectiveness was estimated by comparing time to reach vaccination milestones. We examined vehicle traffic on Vashon ferries and King County highways to understand whether reduced mobility contributed to Vashon’s reduced COVID-19 rates. Results Vashon’s cumulative COVID-19 case rate was 29% that of King County overall and was lower across all age groups and races/ethnicities (both p<.01). A multiple linear regression model showed Vashon to be a significant outlier among King County zip codes with an observed rate 38% of predicted (p<.05), the lowest of any King County zip code. Vashon’s observed COVID-19 hospitalization and death rates were 22% and 32% of those predicted by parallel regression models. Hence, Vashon’s demographics do not explain its reduced COVID rates. Traffic reductions on King County highways and Vashon ferries were nearly identical throughout the study period suggesting altered mobility also does not explain Vashon’s low COVID-19 rates. Effectiveness of VMRC’s COVID-19 response program was demonstrated by 1) highly effective contact tracing that rapidly interviewed 93% of cases and subsequently tested 96% of named contacts, and 2) attainment of vaccination milestones 1-4 months earlier than comparable King County zip codes (p<.01). Conclusion VMRC’s volunteer, COVID-19 response program was associated with significantly fewer COVID-19 cases than predicted from its demographics. VMRC’s contact tracing and vaccination efforts were highly successful and likely contributed to reduced COVID-19 rates. The VMRC experience suggests that a decentralized community-based public health program can be highly effective in implementing epidemic control strategies when focused on an at-risk community. We suggest that MRCs can be particularly effective in extending the reach of county public health departments and should be included in ongoing pandemic planning. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The authors received no specific funding for this work. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Not Applicable The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was approved by the University of California Human Subjects Protection Committee (#22-36518). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Not Applicable I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Not Applicable I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Not Applicable Data have been deposited in Dryad under a paid agreement with UCSF with accession # orcid.org/0000-0002-1971-2273