ABSTRACT
Background: Despite the disproportionate morbidity and mortality experienced by American Indian and Alaska Native (AI/AN) persons during the coronavirus disease 2019 (COVID-19) pandemic, few studies have reported vaccine effectiveness (VE) estimates among these communities. Methods: We conducted a test-negative case-control analysis among AI/AN persons aged ≥12 years presenting for care from January 1, 2021, through November 30, 2021, to evaluate the effectiveness of mRNA COVID-19 vaccines against COVID-19-associated outpatient visits and hospitalizations. Cases and controls were patients with ≥1 symptom consistent with COVID-19-like illness; cases were defined as those test-positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and controls were defined as those test-negative for SARS-CoV-2. We used unconditional multivariable logistic regression to estimate VE, defined as 1 minus the adjusted odds ratio for vaccination among cases vs controls. Results: The analysis included 207 cases and 267 test-negative controls. Forty-four percent of cases and 78% of controls received 2 doses of either BNT162b2 or mRNA-1273 vaccine. VE point estimates for 2 doses of mRNA vaccine were higher for hospitalized participants (94.6%; 95% CI, 88.0-97.6) than outpatient participants (86.5%; 95% CI, 63.0-95.0), but confidence intervals overlapped. Conclusions: Among AI/AN persons, mRNA COVID-19 vaccines were highly effective in preventing COVID-associated outpatient visits and hospitalizations. Maintaining high vaccine coverage, including booster doses, will reduce the burden of disease in this population.
ABSTRACT
SARS-CoV-2 has exposed limitations of public health mitigation measures such as traditional case investigations and contact tracing. The Whiteriver Service Unit is a rural, acute care hospital on the Fort Apache Indian Reservation in Arizona with integrated health care delivery and public health services. During the first wave of COVID-19 cases in May-June 2020, we developed an innovative case investigation contact tracing approach that relied heavily on cross-trained personnel, in-person encounters, and baseline clinical evaluations. A second COVID-19 surge during December 13, 2020-January 31, 2021, caused incidence to peak at 413 cases per 100 000 community members. During that second surge, we investigated all 769 newly identified COVID-19 cases and notified 1911 (99.4%) of 1922 reported contacts. Median time interval from nasopharyngeal specimen collection to both case investigation and contact notification was 0 days (range, 0-5 days and 0-13 days, respectively). Our primary lesson was the importance of cross-trained personnel who integrated tasks along the testing-tracing continuum (eg, in-person interviews, prompt referral for additional testing and evaluation). These successive steps fed forward to identify new cases and their respective contacts. Our innovative community-based approach was both successful and efficient; our experience suggests that when adapted based on local needs, case investigation and contact tracing remain valuable and feasible public health tools, even in rural, resource-limited settings.
Subject(s)
COVID-19 , Contact Tracing , Humans , United States , COVID-19/epidemiology , SARS-CoV-2 , United States Indian Health Service , Arizona/epidemiologyABSTRACT
Indigenous populations have been disproportionally affected by COVID-19, particularly those in rural and remote locations. Their unique environments and risk factors demand an equally unique public health response. Our rural Native American community experienced one of the highest prevalence outbreaks in the world, and we developed an aggressive management strategy that appears to have had a considerable effect on mortality reduction. The results have implications far beyond pandemic response, and have reframed how our community addresses several complicated health challenges. (Am J Public Health. 2021;111(11):1939-1941. https://doi.org/10.2105/AJPH.2021.306472).