Behavioral responses of terrestrial mammals to COVID-19 lockdowns.

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.

Estimates of Bivalent mRNA Vaccine Durability in Preventing COVID-19-Associated Hospitalization and Critical Illness Among Adults with and Without Immunocompromising Conditions - VISION Network, September 2022-April 2023.

On September 1, 2022, CDC's Advisory Committee on Immunization Practices (ACIP) recommended a single bivalent mRNA COVID-19 booster dose for persons aged ≥12 years who had completed at least a monovalent primary series. Early vaccine effectiveness (VE) estimates among adults aged ≥18 years showed receipt of a bivalent booster dose provided additional protection against COVID-19-associated emergency department and urgent care visits and hospitalizations compared with that in persons who had received only monovalent vaccine doses (1); however, insufficient time had elapsed since bivalent vaccine authorization to assess the durability of this protection. The VISION Network* assessed VE against COVID-19-associated hospitalizations by time since bivalent vaccine receipt during September 13, 2022-April 21, 2023, among adults aged ≥18 years with and without immunocompromising conditions. During the first 7-59 days after vaccination, compared with no vaccination, VE for receipt of a bivalent vaccine dose among adults aged ≥18 years was 62% (95% CI = 57%-67%) among adults without immunocompromising conditions and 28% (95% CI = 10%-42%) among adults with immunocompromising conditions. Among adults without immunocompromising conditions, VE declined to 24% (95% CI = 12%-33%) among those aged ≥18 years by 120-179 days after vaccination. VE was generally lower for adults with immunocompromising conditions. A bivalent booster dose provided the highest protection, and protection was sustained through at least 179 days against critical outcomes, including intensive care unit (ICU) admission or in-hospital death. These data support updated recommendations allowing additional optional bivalent COVID-19 vaccine doses for certain high-risk populations. All eligible persons should stay up to date with recommended COVID-19 vaccines.

Effectiveness of COVID-19 Vaccines at Preventing Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompromised Adults: An Observational Study of Real-World Data Across 10 US States from August-December 2021

Background Immunocompromised (IC) persons are at increased risk for severe COVID-19 outcomes and are less protected by 1-2 COVID-19 vaccine doses than are immunocompetent (non-IC) persons. We compared vaccine effectiveness (VE) against medically attended COVID-19 of 2-3 mRNA and 1-2 viral-vector vaccine doses between IC and non-IC adults. Methods Using a test-negative design among eight VISION Network sites, VE against laboratory-confirmed COVID-19–associated emergency department (ED) or urgent care (UC) events and hospitalizations from 26 August-25 December 2021 was estimated separately among IC and non-IC adults and among specific IC condition subgroups. Vaccination status was defined using number and timing of doses. VE for each status (versus unvaccinated) was adjusted for age, geography, time, prior positive test result, and local SARS-CoV-2 circulation. Results We analyzed 8,848 ED/UC events and 18,843 hospitalizations among IC patients and 200,071 ED/UC events and 70,882 hospitalizations among non-IC patients. Among IC patients, 3-dose mRNA VE against ED/UC (73% [95% CI: 64-80]) and hospitalization (81% [95% CI: 76-86]) was lower than that among non-IC patients (ED/UC: 94% [95% CI: 93-94];hospitalization: 96% [95% CI: 95-97]). Similar patterns were observed for viral-vector vaccines. Transplant recipients had lower VE than other IC subgroups. Conclusions During B.1.617.2 (Delta) variant predominance, IC adults received moderate protection against COVID-19–associated medical events from three mRNA doses, or one viral-vector dose plus a second dose of any product. However, protection was lower in IC versus non-IC patients, especially among transplant recipients, underscoring the need for additional protection among IC adults.

The relationship between controllability, optimal testing resource allocation, and incubation-latent period mismatch as revealed by COVID-19.

The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supply-constrained resource allocation strategies for controlling novel disease epidemics. To address the challenge of constrained resource optimization for managing diseases with complications like pre- and asymptomatic transmission, we develop an integro partial differential equation compartmental disease model which incorporates realistic latent, incubation, and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals. Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission. To analyze the influence of these realistic features on disease controllability, we find optimal strategies for reducing total infection sizes that allocate limited testing resources between 'clinical' testing, which targets symptomatic individuals, and 'non-clinical' testing, which targets non-symptomatic individuals. We apply our model not only to the original, delta, and omicron COVID-19 variants, but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions, which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness. We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies, while the relationship between incubation-latent mismatch, controllability, and optimal strategies is complicated. In particular, though greater degrees of presymptomatic transmission reduce disease controllability, they may increase or decrease the role of non-clinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length. Importantly, our model allows a spectrum of diseases to be compared within a consistent framework such that lessons learned from COVID-19 can be transferred to resource constrained scenarios in future emerging epidemics and analyzed for optimality.

Implementation of Multi-level Interventions to Mitigate Risk of SARS-CoV-2 Delta Variant at a PUBLIC UNIVERSITY in Southern United States.

During the coronavirus disease 2019 (COVID-19) pandemic, navigating the implementation of public health measures in a politically charged environment for a large state entity was challenging. However, Louisiana State University (LSU) leadership developed and deployed an effective, multi-layered mitigation plan and successfully opened in-person learning while managing cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the fourth surge. We describe the plan to provide a framework for other institutions during this and future responses. The goals were 3-fold: maintain a quality learning environment, mitigate risk to the campus community, and ensure that LSU operations did not contribute to health-care stress. As of September 2022, LSU has achieved high compliance with interventions and relatively low virus activity on campus compared with peer institutions. This university model can serve as a template for similar implementation plans in the context of complex socio-political and economic considerations.

Effectiveness of BNT162b2 COVID-19 Vaccination in Children and Adolescents.

OBJECTIVES: We assessed BNT162b2 vaccine effectiveness (VE) against mild to moderate and severe coronavirus disease 2019 (COVID-19) in children and adolescents through the Omicron BA.4/BA.5 period. METHODS: Using VISION Network records from April 2021 to September 2022, we conducted a test-negative, case-control study assessing VE against COVID-19-associated emergency department/urgent care (ED/UC) encounters and hospitalizations using logistic regression, conditioned on month and site, adjusted for covariates. RESULTS: We compared 9800 ED/UC cases with 70 232 controls, and 305 hospitalized cases with 2612 controls. During Delta, 2-dose VE against ED/UC encounters at 12 to 15 years was initially 93% (95% confidence interval 89 to 95), waning to 77% (69% to 84%) after ≥150 days. At ages 16 to 17, VE was initially 93% (86% to 97%), waning to 72% (63% to 79%) after ≥150 days. During Omicron, VE at ages 12 to 15 was initially 64% (44% to 77%), waning to 13% (3% to 23%) after ≥150 days; at ages 16 to 17 VE was 31% (10% to 47%) during days 60 to 149, waning to 7% (-8 to 20%) after 150 days. A monovalent booster increased VE to 54% (40% to 65%) at ages 12 to 15 and 46% (30% to 58%) at ages 16 to 17. At ages 5 to 11, 2-dose VE was 49% (33% to 61%) initially and 41% (29% to 51%) after 150 days. During Delta, VE against hospitalizations at ages 12 to 17 was high (>97%), and at ages 16 to 17 remained 98% (73% to 100%) beyond 150 days; during Omicron, hospitalizations were too infrequent to precisely estimate VE. CONCLUSIONS: BNT162b2 protected children and adolescents against mild to moderate and severe COVID-19. VE was lower during Omicron predominance including BA.4/BA.5, waned after dose 2 but increased after a monovalent booster. Children and adolescents should receive all recommended COVID-19 vaccinations.

Recent Increase in Incidence of Severe Acute Hepatitis of Unknown Etiology in Children is Associated with Infection with Adenovirus and Other Nonhepatotropic Viruses.

OBJECTIVE: To evaluate whether the nature and severity of non-A-E severe acute hepatitis in children noted by the World Health Organization from late 2021 through early 2022 was indeed increased in 2021-2022 compared with prior years. STUDY DESIGN: We performed a single-center, retrospective study to track the etiology and outcomes of children with non-A-E severe acute hepatitis in 2021-2022 compared with the prior 3-year periods (2018-2019, 2019-2020, and 2020-2021). We queried electronic medical records of children ≤16 years of age with alanine or aspartate aminotransferase levels of >500 IU. Data were analyzed for the periods of October 1, 2021, to May 1, 2022, and compared with the same time periods in 2018-2021. RESULTS: Of 107 children meeting entry criteria, 82 cases occurred from October to May of 2018-2022. The average annual case number was 16.3 in 2018-2021 compared with a 2-fold increase (to 33) in 2021-2022 (P = .0054). Analyses of etiologies showed that this increase was associated with a higher number of children who tested positive for viruses (n = 16) when compared with the average of 3.7 for 2018-2021 (P = .018). Adenovirus (26.1%) and severe acute respiratory syndrome coronavirus-2 (10.3%) were the most frequently detected viruses in 2021-2022. Despite evidence of acute liver failure in 37.8% of children in the entire cohort and in 47% of those with viral infection, the overall survival rate was high at 91.4% and 88.9%, respectively. CONCLUSIONS: The number of children with severe acute hepatitis in our center increased from 2021 to May 2022, with a greater frequency of cases associated with adenovirus, yet transplant-free survival remains high.

Protection of 2 and 3 mRNA Vaccine Doses Against Severe Outcomes Among Adults Hospitalized with COVID-19 - VISION Network, August 2021 - March 2022.

BACKGROUND: We assessed COVID-19 vaccination impact on illness severity among adults hospitalized with COVID-19 August 2021-March 2022. METHODS: We evaluated differences in intensive care unit (ICU) admission, in-hospital death, and length of stay among vaccinated (2 or 3 mRNA vaccine doses) versus unvaccinated patients aged ≥18 years hospitalized for ≥24 hours with COVID-19-like illness (CLI) and positive SARS-CoV-2 molecular testing. We calculated odds ratios for ICU admission and death and subdistribution hazard ratios (SHR) for time to hospital discharge adjusted for age, geographic region, calendar time, and local virus circulation. RESULTS: We included 27,149 SARS-CoV-2 positive hospitalizations. During both Delta and Omicron-predominant periods, protection against ICU admission was strongest among 3-dose vaccinees compared with unvaccinated patients (Delta OR [CI]: 0.52 [0.28-0.96]); Omicron OR [CI]: 0.69 [0.54-0.87]). During both periods, risk of in-hospital of death was lower among vaccinated compared with unvaccinated but ORs were overlapping; during Omicron, lowest among 3-dose vaccinees (OR [CI] 0.39 [0.28-0.54]). We observed SHR >1 across all vaccination strata in both periods indicating faster discharge for vaccinated patients. CONCLUSIONS: COVID-19 vaccination was associated with lower rates of ICU admission and in-hospital death in both Delta and Omicron periods compared with being unvaccinated.

Online Telesupervision: Competence Forged in a Pandemic

Online telesupervision (OTS) is synchronous (real-time) audio and video interactions between a supervisor and a clinician who are not in the same physical location. The COVID-19 pandemic created an abrupt pivot to OTS, requiring systemic supervisors and clinicians to adopt and utilize technologies which were unfamiliar to many. To facilitate the effective adoption and implementation of OTS we draw attention to three distinct competencies critical to the effective use of OTS: technological, contextual, and relational. These competencies are in no way exhaustive but lay the ground work for systemic supervisors to engage and connect with supervisees using video conferencing technology. In addition to the competencies, specific techniques and strategies are suggested to assist supervisors hone their skills in OTS and subsequently improve the quality and effectiveness of supervision in a virtual environment.

Estimation of COVID-19 mRNA Vaccine Effectiveness and COVID-19 Illness and Severity by Vaccination Status During Omicron BA.4 and BA.5 Sublineage Periods.

Importance: Recent SARS-CoV-2 Omicron variant sublineages, including BA.4 and BA.5, may be associated with greater immune evasion and less protection against COVID-19 after vaccination. Objectives: To evaluate the estimated vaccine effectiveness (VE) of 2, 3, or 4 doses of COVID-19 mRNA vaccination among immunocompetent adults during a period of BA.4 or BA.5 predominant circulation; and to evaluate the relative severity of COVID-19 in hospitalized patients across Omicron BA.1, BA.2 or BA.2.12.1, and BA.4 or BA.5 sublineage periods. Design, Setting, and Participants: This test-negative case-control study was conducted in 10 states with data from emergency department (ED) and urgent care (UC) encounters and hospitalizations from December 16, 2021, to August 20, 2022. Participants included adults with COVID-19-like illness and molecular testing for SARS-CoV-2. Data were analyzed from August 2 to September 21, 2022. Exposures: mRNA COVID-19 vaccination. Main Outcomes and Measures: The outcomes of interest were COVID-19 ED or UC encounters, hospitalizations, and admission to the intensive care unit (ICU) or in-hospital death. VE associated with protection against medically attended COVID-19 was estimated, stratified by care setting and vaccine doses (2, 3, or 4 doses vs 0 doses as the reference group). Among hospitalized patients with COVID-19, demographic and clinical characteristics and in-hospital outcomes were compared across sublineage periods. Results: During the BA.4 and BA.5 predominant period, there were 82 229 eligible ED and UC encounters among patients with COVID-19-like illness (median [IQR] age, 51 [33-70] years; 49 682 [60.4%] female patients), and 19 114 patients (23.2%) had test results positive for SARS-CoV-2; among 21 007 hospitalized patients (median [IQR] age, 71 [58-81] years; 11 209 [53.4%] female patients), 3583 (17.1 %) had test results positive for SARS-CoV-2. Estimated VE against hospitalization was 25% (95% CI, 17%-32%) for receipt of 2 vaccine doses at 150 days or more after receipt, 68% (95% CI, 50%-80%) for a third dose 7 to 119 days after receipt, and 36% (95% CI, 29%-42%) for a third dose 120 days or more (median [IQR], 235 [204-262] days) after receipt. Among patients aged 65 years or older who had received a fourth vaccine dose, VE was 66% (95% CI, 53%-75%) at 7 to 59 days after vaccination and 57% (95% CI, 44%-66%) at 60 days or more (median [IQR], 88 [75-105] days) after vaccination. Among hospitalized patients with COVID-19, ICU admission or in-hospital death occurred in 21.4% of patients during the BA.1 period vs 14.7% during the BA.4 and BA.5 period (standardized mean difference: 0.17). Conclusions and Relevance: In this case-control study of COVID-19 vaccines and illness, VE associated with protection against medically attended COVID-19 illness was lower with increasing time since last dose; estimated VE was higher after receipt of 1 or 2 booster doses compared with a primary series alone.

Disparities in Unilateral Do Not Resuscitate Order Use During the COVID-19 Pandemic.

OBJECTIVES: A unilateral do-not-resuscitate (UDNR) order is a do-not-resuscitate order placed using clinician judgment which does not require consent from a patient or surrogate. This study assessed how UDNR orders were used during the COVID-19 pandemic. DESIGN: We analyzed a retrospective cross-sectional study of UDNR use at two academic medical centers between April 2020 and April 2021. SETTING: Two academic medical centers in the Chicago metropolitan area. PATIENTS: Patients admitted to an ICU between April 2020 and April 2021 who received vasopressor or inotropic medications to select for patients with high severity of illness. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The 1,473 patients meeting inclusion criteria were 53% male, median age 64 (interquartile range, 54-73), and 38% died during admission or were discharged to hospice. Clinicians placed do not resuscitate orders for 41% of patients ( n = 604/1,473) and UDNR orders for 3% of patients ( n = 51/1,473). The absolute rate of UDNR orders was higher for patients who were primary Spanish speaking (10% Spanish vs 3% English; p ≤ 0.0001), were Hispanic or Latinx (7% Hispanic/Latinx vs 3% Black vs 2% White; p = 0.003), positive for COVID-19 (9% vs 3%; p ≤ 0.0001), or were intubated (5% vs 1%; p = 0.001). In the base multivariable logistic regression model including age, race/ethnicity, primary language spoken, and hospital location, Black race (adjusted odds ratio [aOR], 2.5; 95% CI, 1.3-4.9) and primary Spanish language (aOR, 4.4; 95% CI, 2.1-9.4) had higher odds of UDNR. After adjusting the base model for severity of illness, primary Spanish language remained associated with higher odds of UDNR order (aOR, 2.8; 95% CI, 1.7-4.7). CONCLUSIONS: In this multihospital study, UDNR orders were used more often for primary Spanish-speaking patients during the COVID-19 pandemic, which may be related to communication barriers Spanish-speaking patients and families experience. Further study is needed to assess UDNR use across hospitals and enact interventions to improve potential disparities.

Evaluation of an intensive workshop on research methods in supportive oncology.

OBJECTIVES: Since 2015, the Harvard Workshop on Research Methods in Supportive Oncology has trained early-career investigators in skills to develop rigorous studies in supportive oncology. This study examines workshop evaluations over time in the context of two factors: longitudinal participant feedback and a switch from in-person to virtual format during the COVID pandemic. METHODS: We examined post-workshop evaluations for participants who attended the workshop from 2015 to 2021. We qualitatively analyzed evaluation free text responses on ways in which the workshop could be improved and "other comments." Potential areas of improvement were categorized and frequencies were compiled longitudinally. Differences in participants' ratings of the workshop and demographics between in-person and virtual formats were investigated with t-tests and Chi-square tests, respectively. RESULTS: 286 participants attended the workshop over 8 years. Participant ratings of the workshop remained consistently high without substantial variation across all years. Three main themes emerged from the "other comments" item: (1) sense of community; (2) passion and empowerment; and (3) value of protected time. Participants appeared to identify fewer areas for improvement over time. There were no significant differences in participant ratings or demographics between the in-person and virtual formats. SIGNIFINACE OF RESULTS: While the workshop has experienced changes over time, participant evaluations varied little. The core content and structure might have the greatest influence on participants' experiences.

Protection From COVID-19 mRNA Vaccination and Prior SARS-CoV-2 Infection Against COVID-19-Associated Encounters in Adults During Delta and Omicron Predominance.

BACKGROUND: Data assessing protection conferred from COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection during Delta and Omicron predominance periods in the United States are limited. METHODS: This cohort study included persons ≥18 years who had ≥1 health care encounter across 4 health systems and had been tested for SARS-CoV-2 before 26 August 2021. COVID-19 mRNA vaccination and prior SARS-CoV-2 infection defined the exposure. Cox regression estimated hazard ratios (HRs) for the Delta and Omicron periods; protection was calculated as (1-HR)×100%. RESULTS: Compared to unvaccinated and previously uninfected persons, during Delta predominance, protection against COVID-19-associated hospitalizations was high for those 2- or 3-dose vaccinated and previously infected, 3-dose vaccinated alone, and prior infection alone (range, 91%-97%, with overlapping 95% confidence intervals [CIs]); during Omicron predominance, estimates were lower (range, 77%-90%). Protection against COVID-19-associated emergency department/urgent care (ED/UC) encounters during Delta predominance was high for those exposure groups (range, 86%-93%); during Omicron predominance, protection remained high for those 3-dose vaccinated with or without a prior infection (76%; 95% CI = 67%-83% and 71%; 95% CI = 67%-73%, respectively). CONCLUSIONS: COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection provided protection against COVID-19-associated hospitalizations and ED/UC encounters regardless of variant. Staying up-to-date with COVID-19 vaccination still provides protection against severe COVID-19 disease, regardless of prior infection.

Keeping the Lights On: The Impact of the COVID-19 Pandemic on Elective Total Joint Arthroplasty Utilization in the United States.

Background: It was estimated that up to 30,000 primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures would be cancelled each week during the moratorium on elective surgeries in the United States (US). The purpose of this study was to analyze the impact of the COVID-19 pandemic on elective total joint arthroplasty (TJA) utilization in the US. Methods: A retrospective study was conducted using the PearlDiver database. Patients who underwent primary elective THA and TKA were identified and filtered by state and month from January through September of both 2019 and 2020. The volume of these procedures immediately following the moratorium on elective surgeries were compared to the same months the previous year. Results: For THA, overall, there was a 27.39% reduction in THA volume from 2019 to 2020 in March and an 88.94% reduction in April. For TKA, overall, there was a 31.28% reduction in TKA volume in March and a 96.61% reduction in April. When the states were separated into two cohorts by 2020 presidential election vote, there was a significantly larger decrease in THA and TKA volume observed in the 25 states and Washington DC that voted democrat compared to the 25 states that voted republican in both March (p < 0.05) and April (p < 0.05). Both THA (118.29%) and TKA (101.02%) volume returned to pre-pandemic levels by June. Conclusion: Overall, this study demonstrated that elective TJA utilization did reduce as anticipated following the CMS moratorium on elective surgeries but quickly returned to pre-pandemic levels by June.

Attention to climate change only temporarily diverted by COVID-19 (preprint)

The COVID-19 pandemic disrupted peoples’ daily lives and dominated the public discourse. It thus displaced people’s attention to and concerns about climate change. We analyze 13.5 million tweets on climate change posted before and after the onset of the pandemic (2018–2021) and show that attention to climate dropped substantially in 2020 with the onset of the pandemic. While research has helped to explain this drop in the context of issue attention theory, our analysis highlights a remarkable recovery in attention in 2021 towards pre-pandemic levels. Moreover, our large-scale, transformer-based text analysis reveals important thematic shifts during this period. In particular, we show a sustained drop in attention to activist movements and subsequently an increased focus on climate causes and climate solutions. This means, that while the climate change discourse in general recovered from the COVID-19 pandemic, activist movements such as the school protests that have mobilized millions around the globe in 2019 have measurably lost traction on Twitter.

Myocardial Infarction across COVID-19 Pandemic Phases: Insights from the Veterans Health Affairs System (preprint)

Background Cardiovascular procedural treatments were deferred at scale during the COVID-19 pandemic, with unclear impact on patients presenting with Non-ST Elevation Myocardial Infarction (NSTEMI). Methods In a retrospective cohort study of all patients diagnosed with NSTEMI in the U.S. Veterans Affairs Healthcare System from 1/1/19 to 10/30/22 (n=67,125), procedural treatments and outcomes were compared between the pre-pandemic period and six unique pandemic phases (1: Acute phase, 2: Community spread, 3: First Peak, 4: Post-Vaccine, 5. Second Peak, 6. Recovery). Multivariable regression analysis was performed to assess association between pandemic phases and 30-day mortality. Results NSTEMI volumes dropped significantly with the pandemic onset (62.7% of pre-pandemic peak) and did not revert to pre-pandemic levels in subsequent phases, even after vaccine availability. Percutaneous coronary intervention (PCI) and/or coronary artery bypass grafting (CABG) volumes declined proportionally. Compared to the pre-pandemic period, NSTEMI patients experienced higher 30-day mortality during Phase 2 and 3, even after adjustment for COVID-19 positive status, demographics, baseline comorbidities, and receipt of procedural treatment (adjusted OR for Phase 2-3 combined: 1.26 [95% CI 1.13-1.43], p<0.01). Patients receiving VA-paid community care had a higher adjusted risk of 30-day mortality compared to those at VA hospitals across all six pandemic phases. Conclusions Higher mortality after NSTEMI occurred during the initial spread and first peak of the pandemic, but resolved before the second, higher peak - suggesting effective adaptation of care delivery but a costly delay to implementation. Investigation into the vulnerabilities of the early pandemic spread are vital to informing future resource-constrained practices.

Relationships Between Social Vulnerability and Coronavirus Disease 2019 Vaccination Coverage and Vaccine Effectiveness.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccination coverage remains lower in communities with higher social vulnerability. Factors such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure risk and access to healthcare are often correlated with social vulnerability and may therefore contribute to a relationship between vulnerability and observed vaccine effectiveness (VE). Understanding whether these factors impact VE could contribute to our understanding of real-world VE. METHODS: We used electronic health record data from 7 health systems to assess vaccination coverage among patients with medically attended COVID-19-like illness. We then used a test-negative design to assess VE for 2- and 3-dose messenger RNA (mRNA) adult (≥18 years) vaccine recipients across Social Vulnerability Index (SVI) quartiles. SVI rankings were determined by geocoding patient addresses to census tracts; rankings were grouped into quartiles for analysis. RESULTS: In July 2021, primary series vaccination coverage was higher in the least vulnerable quartile than in the most vulnerable quartile (56% vs 36%, respectively). In February 2022, booster dose coverage among persons who had completed a primary series was higher in the least vulnerable quartile than in the most vulnerable quartile (43% vs 30%). VE among 2-dose and 3-dose recipients during the Delta and Omicron BA.1 periods of predominance was similar across SVI quartiles. CONCLUSIONS: COVID-19 vaccination coverage varied substantially by SVI. Differences in VE estimates by SVI were minimal across groups after adjusting for baseline patient factors. However, lower vaccination coverage among more socially vulnerable groups means that the burden of illness is still disproportionately borne by the most socially vulnerable populations.