Comparable Outcomes for Bebtelovimab and Ritonavir-Boosted Nirmatrelvir Treatment in High-Risk Patients With Coronavirus Disease-2019 During Severe Acute Respiratory Syndrome Coronavirus 2 BA.2 Omicron Epoch.

The effectiveness of bebtelovimab in real-world settings has not been assessed. In this retrospective cohort study of 3607 high-risk patients, bebtelovimab was used more commonly than nirmatrelvir-ritonavir for treatment of coronavirus disease 2019 (COVID-19) among older patients, immunosuppressed patients, and those with multiple comorbid conditions. Despite its use in patients with multiple comorbid conditions, the rate of progression to severe disease after bebtelovimab (1.4% [95% confidence interval, 1.2%-1.7%]) was not significantly different from that for nirmatrelvir-ritonavir treatment (1.2% [.8%-1.5%]). Our findings support the emergency use authorization of bebtelovimab for treatment of COVID-19 during the Omicron epoch dominated by BA.2 and subvariants.

Coronavirus Disease 2019 Vaccine-Breakthrough Infections Requiring Hospitalization in Mayo Clinic Florida Through August 2021.

We characterized coronavirus disease 2019 (COVID-19) breakthrough cases admitted to a single center in Florida. With the emergence of delta variant, an increased number of hospitalizations was seen due to breakthrough infections. These patients were older and more likely to have comorbidities. Preventive measures should be maintained even after vaccination.

Low antispike antibody levels correlate with poor outcomes in COVID-19 breakthrough hospitalizations.

BACKGROUND: While COVID-19 immunization programs attempted to reach targeted rates, cases rose significantly since the emergence of the delta variant. This retrospective cohort study describes the correlation between antispike antibodies and outcomes of hospitalized, breakthrough cases during the delta variant surge. METHODS: All patients with positive SARS-CoV-2 polymerase chain reaction hospitalized at Mayo Clinic Florida from 19 June 2021 to 11 November 2021 were considered for analysis. Cases were analyzed by vaccination status. Breakthrough cases were then analyzed by low and high antibody titers against SARS-CoV-2 spike protein, with a cut-off value of ≥132 U/ml. Outcomes included hospital length of stay (LOS), need for intensive care unit (ICU), mechanical ventilation, and mortality. We used 1:1 nearest neighbor propensity score matching without replacement to assess for confounders. RESULTS: Among 627 hospitalized patients with COVID-19, vaccine breakthrough cases were older with more comorbidities compared to unvaccinated. After propensity score matching, the unvaccinated patients had higher mortality (27 [28.4%] vs. 12 [12.6%], p = 0.002) and LOS (7 [1.0-57.0] vs. 5 [1.0-31.0] days, p = 0.011). In breakthrough cases, low-titer patients were more likely to be solid organ transplant recipients (16 [34.0%] vs. 9 [12.3%], p = 0.006), with higher need for ICU care (24 [51.1%] vs. 22 [11.0%], p = 0.034), longer hospital LOS (median 6 vs. 5 days, p = 0.013), and higher mortality (10 [21.3%] vs. 5 [6.8%], p = 0.025) than high-titer patients. CONCLUSIONS: Hospitalized breakthrough cases were more likely to have underlying risk factors than unvaccinated patients. Low-spike antibody titers may serve as an indicator for poor prognosis in breakthrough cases admitted to the hospital.

Real-World Clinical Outcomes of Bamlanivimab and Casirivimab-Imdevimab Among High-Risk Patients With Mild to Moderate Coronavirus Disease 2019.

BACKGROUND: Bamlanivimab and casirivimab-imdevimab are authorized for treatment of mild to moderate coronavirus disease 2019 (COVID-19) in high-risk patients. We compared the outcomes of patients who received these therapies to identify factors associated with hospitalization and other clinical outcomes. METHODS: Adult patients who received monoclonal antibody from 19 November 2020 to 11 February 2021 were selected and divided into those who received bamlanivimab (n = 2747) and casirivimab-imdevimab (n = 849). The 28-day all-cause and COVID-19-related hospitalizations were compared between the groups. RESULTS: The population included 3596 patients; the median age was 62 years, and 50% were female. All had ≥1 medical comorbidity; 55% had multiple comorbidities. All-cause and COVID-19-related hospitalization rates at 28 days were 3.98% and 2.56%, respectively. After adjusting for medical comorbidities, there was no significant difference in all-cause and COVID-19-related hospitalization rates between bamlanivimab and casirivimab-imdevimab (adjusted hazard ratios [95% confidence interval], 1.4 [.9-2.2] and 1.6 [.8-2.7], respectively). Chronic kidney, respiratory and cardiovascular diseases, and immunocompromised status were associated with higher likelihood of hospitalization. CONCLUSIONS: This observational study on the use of bamlanivimab and casirivimab-imdevimab in high-risk patients showed similarly low rates of hospitalization. The number and type of medical comorbidities are associated with hospitalizations after monoclonal antibody treatment.

Completion lymph node dissection in patients with sentinel lymph node positive cutaneous head and neck melanoma.

BACKGROUND: Relatively few cutaneous head and neck melanoma (CHNM) patients with were included in the multicenter selective lymphadenectomy trial II (MSLT-II). Our objective was to investigate whether immediate completion lymph node dissection completion of lymph node dissection (CLND) was associated with survival benefit for sentinel lymph node (SLN) positive CHNM using the National Cancer Database. METHODS: SLN positive patients with CHNM from 2012 to 2014 were retrospectively analyzed. Patients were divided into two groups: those who underwent SLN biopsy (SLNB) only versus those who underwent SLNB followed by CLND (SLNB + CLND). The primary outcome was 5-year overall survival (OS). RESULTS: Among 530 SLNB + patients, 342 patients underwent SLNB followed by CLND (SLNB + CLND). The SLNB only group had fewer positive SLN, less advanced pathologic stage, and a lower rate of adjuvant immunotherapy. There was no significant difference in 5-year OS between the two groups (51.0% vs 67%; P = .56). After adjusting for pathologic stage, there remained no difference in 5-year OS among patients with stage IIIA (63.0% vs. 73.6%, P = 0.22) or IIIB/IIIC disease (39.1% vs 57.8%; P = .52). Conclusions Using a large nationwide database, CLND was not shown to be associated with improved OS for patients with SLNB positive CHNM, validating the results of MSLT-II.

Establishing Mayo Clinic's Coronavirus Disease 2019 Virtual Clinic: A Preliminary Communication.

The coronavirus disease 2019 (COVID-19) pandemic is taking a massive toll on health care systems globally. We developed the COVID-19 virtual clinic (CVC) in conjunction with drive through testing to cope with this situation. There are two arms of the CVC: (1) a screening arm and (2) positive patient arm. Screening is performed over the phone based on the Centers for Disease Control and Prevention screening guideline. Positive patients are followed at regular intervals by video appointments where concerns can be addressed by a provider while also tracking symptom progression. We enrolled 63 positive patients out of 1,153 screened for COVID-19 as of this writing. The CVC continues to address patients' concerns and symptoms in an effort to minimize emergency department and hospital patient volumes, as incidence increases. Drive through testing in conjunction with a virtual clinic allows us to provide high-quality care in an anxious time without consuming excessive personal protective equipment or unnecessarily exposing health care workers. This article could serve as a model to guide other practices to cope with this and future pandemics.

Intravenous Access in Gastrointestinal Hemorrhage: A Multidisciplinary Quality Improvement Initiative Led by Emergency Department Nurses and Internal Medicine Physicians.

BACKGROUND: The management of acute gastrointestinal hemorrhage (GIH) is focused on early resuscitation through 2 large-bore intravenous (2LBIV) catheters, although adherence to this recommendation is low. LOCAL PROBLEM: Of 100 patients hospitalized with GIH in 2017, only 14 received 2LBIV access. The goal of this study was to improve this measure. METHODS: A multidisciplinary team used the DMAIC (define, measure, analyze, improve, and control) framework to perform a quality improvement initiative. INTERVENTIONS: The team used quality tools including a stakeholder survey, swimlane diagram, and fishbone diagram. The first intervention involved education of the hospitalists directing admissions, and the second intervention involved education of emergency department (ED) physicians and nurses regarding the importance of 2LBIV placement. RESULTS: Following the second intervention, there was a substantial increase in 2LBIV placement to 37 of 86 (43%). CONCLUSIONS: Carefully directed education of ED physicians and nurses with monthly feedback was effective in improving appropriate intravenous placement in patients with GIH.

Communication Training Helps to Reduce Burnout During COVID-19 Pandemic.

Objective: To determine the effectiveness of communication training and its impact on burnout among healthcare providers (physicians, physician assistants, nurse practitioners), in the setting of the COVID-19 pandemic. Methods: To evaluate the effectiveness of communication training on burnout during the COVID-19 pandemic, healthcare providers participating in a Communication in Healthcare (CIH) module between October 31, 2019, through February 20, 2020, were identified using a scanned sign-in sheet. A 3-question online survey regarding the utilization of communication skills during the COVID-19 pandemic was sent via email. An ordinal scale was used to rate the effectiveness of the training on subsequent burnout and work satisfaction during the pandemic. Results: Of the 98 surveys distributed via email, a total of 33 participants completed the survey. Seventy-three percent of respondents agreed that communication training helped prevent burnout, and 39% strongly agreed that the modules improved work satisfaction. Conclusion: Our study found communication training was effective in reducing burnout in healthcare providers, in the setting of the COVID-19 pandemic. The participants felt the communication tools learned from the training modules were useful in improving work satisfaction and communication with patients during the pandemic.

Association of Neutralizing Antispike Monoclonal Antibody Treatment With Coronavirus Disease 2019 Hospitalization and Assessment of the Monoclonal Antibody Screening Score.

Objective: To test the hypothesis that the Monoclonal Antibody Screening Score performs consistently better in identifying the need for monoclonal antibody infusion throughout each "wave" of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant predominance during the coronavirus disease 2019 (COVID-19) pandemic and that the infusion of contemporary monoclonal antibody treatments is associated with a lower risk of hospitalization. Patients and Methods: In this retrospective cohort study, we evaluated the efficacy of monoclonal antibody treatment compared with that of no monoclonal antibody treatment in symptomatic adults who tested positive for SARS-CoV-2 regardless of their risk factors for disease progression or vaccination status during different periods of SARS-CoV-2 variant predominance. The primary outcome was hospitalization within 28 days after COVID-19 diagnosis. The study was conducted on patients with a diagnosis of COVID-19 from November 19, 2020, through May 12, 2022. Results: Of the included 118,936 eligible patients, hospitalization within 28 days of COVID-19 diagnosis occurred in 2.52% (456/18,090) of patients who received monoclonal antibody treatment and 6.98% (7,037/100,846) of patients who did not. Treatment with monoclonal antibody therapies was associated with a lower risk of hospitalization when using stratified data analytics, propensity scoring, and regression and machine learning models with and without adjustments for putative confounding variables, such as advanced age and coexisting medical conditions (eg, relative risk, 0.15; 95% CI, 0.14-0.17). Conclusion: Among patients with mild to moderate COVID-19, including those who have been vaccinated, monoclonal antibody treatment was associated with a lower risk of hospital admission during each wave of the COVID-19 pandemic.

Cardiovascular Concerns from COVID-19 in Pilots.

BACKGROUND: Cardiovascular disease, now complicated by the COVID-19 pandemic, remains a leading cause of death and risk for sudden incapacitation for pilots during flight. The capacity for aeromedically significant cardiovascular sequelae with potentially imperceptible clinical symptoms elicits concern both during and following resolution of acute COVID-19 in pilots.OBJECTIVE: We summarize the current state of knowledge regarding COVID-19 cardiovascular implications as applied to the aviation environment to better understand their significance toward flight safety and application toward a focused cardiovascular screening protocol following recovery from infection.METHODS: A narrative review of the cardiovascular implications of COVID-19 infection was performed using the PubMed literature search engine and existing organizational guidelines. In addition, to established medical aviation benchmarks, surrogate populations examined included high performance athletes (as a correlate for high G-forces), and scuba divers (as an environmental work analog). Conditions of primary concern included myocardial injury, proarrhythmic substrates, risk of sudden death, myopericarditis, pulse orthostatic lability in response to vigorous activity, cardiovagal dysfunction, and thromboembolic disease.LITERATURE REVIEW: Cardiovascular screening guideline recommendations post-infection recovery are suggested based on profile stratification: airperson flight class, tactical military, and aerobatic pilots. This provides an approach to inform aeromedical decision making.CONCLUSION: Aviation medical examiners should remain cognizant of the clinically apparent and occult manifestations of cardiovascular dysfunction associated with COVID-19 infection when applying return-to-work screening guidelines. This will ensure high flight safety standards are maintained and sudden incapacitation risk mitigated during and following the ongoing pandemic.Elkhatib W, Herrigel D, Harrison M, Flipse T, Speicher L. Cardiovascular concerns from COVID-19 in pilots. Aerosp Med Hum Perform. 2022; 93(12):855-865.

SARS-CoV-2 and influenza coinfection throughout the COVID-19 pandemic: an assessment of coinfection rates, cohort characteristics, and clinical outcomes.

Case reports of patients infected with COVID-19 and influenza virus ("flurona") have raised questions around the prevalence and severity of coinfection. Using data from HHS Protect Public Data Hub, NCBI Virus, and CDC FluView, we analyzed trends in SARS-CoV-2 and influenza hospitalized coinfection cases and strain prevalences. We also characterized coinfection cases across the Mayo Clinic Enterprise from January 2020 to April 2022. We compared expected and observed coinfection case counts across different waves of the pandemic and assessed symptoms and outcomes of coinfection and COVID-19 monoinfection cases after propensity score matching on clinically relevant baseline characteristics. From both the Mayo Clinic and nationwide datasets, the observed coinfection rate for SARS-CoV-2 and influenza has been higher during the Omicron era (2021 December 14 to 2022 April 2) compared to previous waves, but no higher than expected assuming infection rates are independent. At the Mayo Clinic, only 120 coinfection cases were observed among 197,364 SARS-CoV-2 cases. Coinfected patients were relatively young (mean age: 26.7 years) and had fewer serious comorbidities compared to monoinfected patients. While there were no significant differences in 30-day hospitalization, ICU admission, or mortality rates between coinfected and matched COVID-19 monoinfection cases, coinfection cases reported higher rates of symptoms including congestion, cough, fever/chills, headache, myalgia/arthralgia, pharyngitis, and rhinitis. While most coinfection cases observed at the Mayo Clinic occurred among relatively healthy individuals, further observation is needed to assess outcomes among subpopulations with risk factors for severe COVID-19 such as older age, obesity, and immunocompromised status.

Real-world Clinical Outcomes of Bebtelovimab and Sotrovimab Treatment of High-risk Persons With Coronavirus Disease 2019 During the Omicron Epoch.

Background: Antispike monoclonal antibodies are recommended for early treatment of high-risk persons with mild to moderate coronavirus disease 2019 (COVID-19). However, clinical outcomes of their use during the severe acute respiratory syndrome coronavirus 2 Omicron wave are limited. Methods: This is a descriptive retrospective study of high-risk adult patients who received treatment with sotrovimab (January 1-March 20, 2022) or bebtelovimab (March 21-April 30, 2022). The primary outcome was the proportion of patients who progressed to severe outcome within 30 days after receiving antispike-neutralizing monoclonal antibody infusion. Results: A total of 3872 high-risk patients (median age, 62.7 years; 41.1% male) with mild to moderate COVID-19 received sotrovimab (n = 2182) or bebtelovimab (n = 1690). Among sotrovimab-treated patients, the most common comorbidities were an immunosuppressed condition (46.7%), hypertension (38.2%), and diabetes (21.2%). The rates of severe outcome, intensive care unit (ICU) admission, and mortality were 2.2%, 1.0%, and 0.4%, respectively, after sotrovimab infusion. Among bebtelovimab-treated patients, the most common comorbidities were hypertension (42.7%), diabetes (17.1%), and an immunosuppressed condition (17.0%). The rates of severe disease, ICU admission, and mortality were 1.3%, 0.5%, and 0.2%, respectively, after bebtelovimab infusion. Older age, immunosuppressed status, and several comorbidities were associated with severe disease progression, while COVID-19 vaccination was associated with lower risk. No anaphylaxis was reported during monoclonal antibody infusion. Conclusions: This real-world analysis of a large cohort of high-risk patients demonstrates low rates of severe disease after treatment with sotrovimab during the era dominated by Omicron B.1.1.529 and after treatment with bebtelovimab during the era dominated by BA.2 and Omicron subvariants.

Clinical and laboratory profiles of the SARS-CoV-2 Delta variant compared with pre-Delta variants.

OBJECTIVES: The emergence of SARS-CoV-2 variants of concern has led to significant phenotypical changes in transmissibility, virulence, and public health measures. Our study used clinical data to compare characteristics between a Delta variant wave and a pre-Delta variant wave of hospitalized patients. METHODS: This single-center retrospective study defined a wave as an increasing number of COVID-19 hospitalizations, which peaked and later decreased. Data from the United States Department of Health and Human Services were used to identify the waves' primary variant. Wave 1 (August 8, 2020-April 1, 2021) was characterized by heterogeneous variants, whereas Wave 2 (June 26, 2021-October 18, 2021) was predominantly the Delta variant. Descriptive statistics, regression techniques, and machine learning approaches supported the comparisons between waves. RESULTS: From the cohort (N = 1318), Wave 2 patients (n = 665) were more likely to be younger, have fewer comorbidities, require more care in the intensive care unit, and show an inflammatory profile with higher C-reactive protein, lactate dehydrogenase, ferritin, fibrinogen, prothrombin time, activated thromboplastin time, and international normalized ratio compared with Wave 1 patients (n = 653). The gradient boosting model showed an area under the receiver operating characteristic curve of 0.854 (sensitivity 86.4%; specificity 61.5%; positive predictive value 73.8%; negative predictive value 78.3%). CONCLUSION: Clinical and laboratory characteristics can be used to estimate the COVID-19 variant regardless of genomic testing availability. This finding has implications for variant-driven treatment protocols and further research.

Effectiveness of Monoclonal Antibodies in Preventing Severe COVID-19 With Emergence of the Delta Variant.

Anti-spike monoclonal antibodies have proven invaluable in preventing severe outcomes from COVID-19, including hospitalization and death. The rise of the SARS-CoV-2 delta variant begs the question of whether monoclonal antibodies maintain similar efficacy now as they had when the alpha and beta variants predominated, when they were first assessed and approved. We used a retrospective cohort to compare rates of severe outcomes in an epoch in which alpha and beta were predominant compared with delta. A total of 5356 patients were infused during the alpha/beta variant-predominant (n=4874) and delta variant-predominant (n=482) era. Overall, odds of severe infection were 3.0% of patients in the alpha/beta-predominant era compared with 4.9% in the delta-predominant cohort. The unadjusted odds ratio (OR) was higher for severe disease in the delta era (OR, 1.67; 95% CI, 0.96 to 2.89), particularly when adjusted for Charlson Comorbidity Index (adjusted OR, 2.04; 95% CI, 1.30 to 3.08). The higher odds of severe infection could be due to a more virulent delta variant, although the possibility of decreased anti-spike monoclonal antibody effectiveness in the clinical setting cannot be excluded. Research into the most effective strategies for using and improving anti-spike monoclonals for the treatment of emerging variants is warranted.

Surveillance of Safety of 3 Doses of COVID-19 mRNA Vaccination Using Electronic Health Records.

Importance: Recent reports on waning of COVID-19 vaccine-induced immunity have led to the approval and rollout of additional doses and booster vaccinations. Individuals at increased risk of SARS-CoV-2 infection are receiving additional vaccine doses in addition to the regimen that was tested in clinical trials. Risks and adverse event profiles associated with additional vaccine doses are currently not well understood. Objective: To evaluate the safety of third-dose vaccination with US Food and Drug Administration (FDA)-approved COVID-19 mRNA vaccines. Design, Setting, and Participants: This cohort study was conducted using electronic health record (EHR) data from December 2020 to October 2021 from the multistate Mayo Clinic Enterprise. Participants included all 47 999 individuals receiving 3-dose COVID-19 mRNA vaccines within the study setting who met study inclusion criteria. Participants were divided into 2 cohorts by vaccine brand administered and served as their own control groups, with no comparison made between cohorts. Data were analyzed from September through November 2021. Exposures: Three doses of an FDA-authorized COVID-19 mRNA vaccine, BNT162b2 or mRNA-1273. Main Outcomes and Measures: Vaccine-associated adverse events were assessed via EHR report. Adverse event risk was quantified using the percentage of study participants who reported the adverse event within 14 days after each vaccine dose and during a 14-day control period, immediately preceding the first vaccine dose. Results: Among 47 999 individuals who received 3-dose COVID-19 mRNA vaccines, 38 094 individuals (21 835 [57.3%] women; median [IQR] age, 67.4 [52.5-76.5] years) received BNT162b2 (79.4%) and 9905 individuals (5099 [51.5%] women; median [IQR] age, 67.7 [59.5-73.9] years) received mRNA-1273 (20.6%). Reporting of severe adverse events remained low after the third vaccine dose, with rates of pericarditis (0.01%; 95% CI, 0%-0.02%), anaphylaxis (0%; 95% CI, 0%-0.01%), myocarditis (0%; 95% CI, 0%-0.01%), and cerebral venous sinus thrombosis (no individuals) consistent with results from earlier studies. Significantly more individuals reported low-severity adverse events after the third dose compared with after the second dose, including fatigue (2360 individuals [4.92%] vs 1665 individuals [3.47%]; P < .001), lymphadenopathy (1387 individuals [2.89%] vs 995 individuals [2.07%]; P < .001), nausea (1259 individuals [2.62%] vs 979 individuals [2.04%]; P < .001), headache (1185 individuals [2.47%] vs 992 individuals [2.07%]; P < .001), arthralgia (1019 individuals [2.12%] vs 816 individuals [1.70%]; P < .001), myalgia (956 individuals [1.99%] vs 784 individuals [1.63%]; P < .001), diarrhea (817 individuals [1.70%] vs 595 individuals [1.24%]; P < .001), fever (533 individuals [1.11%] vs 391 individuals [0.81%]; P < .001), vomiting (528 individuals [1.10%] vs 385 individuals [0.80%]; P < .001), and chills (224 individuals [0.47%] vs 175 individuals [0.36%]; P = .01). Conclusions and Relevance: This study found that although third-dose vaccination against SARS-CoV-2 infection was associated with increased reporting of low-severity adverse events, risk of severe adverse events remained comparable with risk associated with the standard 2-dose regime. These findings suggest the safety of third vaccination doses in individuals who were eligible for booster vaccination at the time of this study.

Impact of a High-Risk, Ambulatory COVID-19 Remote Patient Monitoring Program on Utilization, Cost, and Mortality.

OBJECTIVE: To evaluate care utilization, cost, and mortality among high-risk patients enrolled in a coronavirus disease 2019 (COVID-19) remote patient monitoring (RPM) program. METHODS: This retrospective analysis included patients diagnosed with COVID-19 at risk for severe disease who enrolled in the RPM program between March 2020 and October 2021. The program included in-home technology for symptom and physiologic data monitoring with centralized care management. Propensity score matching established matched cohorts of RPM-engaged (defined as ≥1 RPM technology interactions) and non-engaged patients using a logistic regression model of 59 baseline characteristics. Billing codes and the electronic death certificate system were used for data abstraction from the electronic health record and reporting of care utilization and mortality endpoints. RESULTS: Among 5796 RPM-enrolled patients, 80.0% engaged with the technology. Following matching, 1128 pairs of RPM-engaged and non-engaged patients comprised the analysis cohorts. Mean patient age was 63.3 years, 50.9% of patients were female, and 81.9% were non-Hispanic White. Patients who were RPM-engaged experienced significantly lower rates of 30-day, all-cause hospitalization (13.7% vs 18.0%, P=.01), prolonged hospitalization (3.5% vs 6.7%, P=.001), intensive care unit admission (2.3% vs 4.2%, P=.01), and mortality (0.5% vs 1.7%; odds ratio, 0.31; 95% CI, 0.12 to 0.78; P=.01), as well as cost of care ($2306.33 USD vs $3565.97 USD, P=0.04), than those enrolled in RPM but non-engaged. CONCLUSION: High-risk COVID-19 patients enrolled and engaged in an RPM program experienced lower rates of hospitalization, intensive care unit admission, mortality, and cost than those enrolled and non-engaged. These findings translate to improved hospital bed access and patient outcomes.

Comparative effectiveness of mRNA-1273 and BNT162b2 against symptomatic SARS-CoV-2 infection.

BACKGROUND: mRNA coronavirus disease 2019 (COVID-19) vaccines are safe and effective, but increasing reports of breakthrough infections highlight the need to vigilantly monitor and compare the effectiveness of these vaccines. METHODS: We retrospectively compared protection against symptomatic infection conferred by mRNA-1273 and BNT162b2 at Mayo Clinic sites from December 2020 to September 2021. We used a test-negative case-control design to estimate vaccine effectiveness (VE) and to compare the odds of symptomatic infection after full vaccination with mRNA-1273 versus BNT162b2, while adjusting for age, sex, race, ethnicity, geography, comorbidities, and calendar time of vaccination and testing. FINDINGS: Both vaccines were highly effective over the study duration (VEmRNA-1273: 84.1%, 95% confidence interval [CI]: 81.6%-86.2%; VEBNT162b2: 75.6%, 95% CI: 72.2%-78.7%), but their effectiveness was reduced during July-September (VEmRNA-1273: 75.6%, 95% CI: 70.1%-80%; VEBNT162b2: 63.5%, 95% CI: 55.8%-69.9%) as compared to December-May (VEmRNA-1273: 93.7%, 95% CI: 90.4%-95.9%; VEBNT162b2: 85.7%, 95% CI: 81.4%-88.9%). Adjusted for demographic characteristics, clinical comorbidities, time of vaccination, and time of testing, the odds of experiencing a symptomatic breakthrough infection were lower after full vaccination with mRNA-1273 than with BNT162b2 (odds ratio: 0.60; 95% CI: 0.55-0.67). CONCLUSIONS: Both mRNA-1273 and BNT162b2 strongly protect against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is imperative to continue monitoring and comparing available vaccines over time and with respect to emerging variants to inform public and global health decisions. FUNDING: This study was funded by nference.