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Clinical epidemiology and risk factors for critical outcomes among vaccinated and unvaccinated adults hospitalized with COVID-19-VISION Network, 10 States, June 2021-March 2023

The epidemiology of COVID-19 continues to develop with emerging variants, expanding population-level immunity, and advances in clinical care. We describe changes in the clinical epidemiology of hospitalized COVID-19 and risk factors for critical outcomes over time. We included adults aged…

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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

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…

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Effectiveness of Monovalent and Bivalent mRNA Vaccines in Preventing COVID-19-Associated Emergency Department and Urgent Care Encounters Among Children Aged 6 Months-5 Years – VISION Network, United States, July 2022-June 2023

On June 19, 2022, the original monovalent mRNA COVID-19 vaccines were approved as a primary series for children aged 6 months-4 years (Pfizer-BioNTech) and 6 months-5 years (Moderna) based on safety, immunobridging, and limited efficacy data from clinical trials. On…

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Real-World Evidence to Supplement Randomized Clinical Trials: Tocilizumab for Severe COVID-19 Pneumonia vs. a Cohort Receiving Standard of Care

Randomized controlled trials (RCTs) remain the gold standard for evaluating treatment efficacy, but real-world evidence can supplement RCT results. Tocilizumab was not found to reduce 28-day mortality in a phase III, double-blind, placebo-controlled trial (COVACTA) among hospitalized patients with severe…

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Effect of the P-selectin Inhibitor Crizanlizumab on Survival Free of Organ Support in Patients Hospitalized for COVID-19: A Randomized Controlled Trial

COVID-19 has been associated with endothelial injury, resultant microvascular inflammation and thrombosis. Activated endothelial cells release and express P-selectin and von Willebrand factor, both of which are elevated in severe COVID-19 and may be implicated in the disease pathophysiology. We…

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Number needed to vaccinate with a COVID-19 booster to prevent a COVID-19-associated hospitalization during SARS-CoV-2 Omicron BA.1 variant predominance, December 2021-February 2022, VISION Network: a retrospective cohort study

Understanding the usefulness of additional COVID-19 vaccine doses-particularly given varying disease incidence-is needed to support public health policy. We characterize the benefits of COVID-19 booster doses using number needed to vaccinate (NNV) to prevent one COVID-19-associated hospitalization or emergency department…

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Rivaroxaban for Prevention of Thrombotic Events, Hospitalization, and Death in Outpatients With COVID-19: A Randomized Clinical Trial

COVID-19 (coronavirus disease 2019) is associated with heightened risks of venous and arterial thrombosis and hospitalization due to respiratory failure. To assess whether prophylactic anticoagulation can safely reduce the frequency of venous and arterial thrombosis, hospitalization, and death in nonhospitalized…

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Social Risks, Social Needs, and Attitudes Toward Social Health Screening 1 Year Into the COVID-19 Pandemic: Survey of Adults in an Integrated Health Care Delivery System

Introduction Information about demographic differences in social risks, needs, and attitudes toward social health screening in non-highly vulnerable adult populations is lacking. Methods The authors analyzed data for 2869 Kaiser Permanente Northern California non-Medicaid-covered members aged 35 to 85 who…

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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…

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SARS-CoV-2 Delta variant genomic variation associated with breakthrough infection in Northern California: A retrospective cohort study

The association between SARS-CoV-2 genomic variation and breakthrough infection is not well-defined among persons with Delta variant SARS-CoV-2 infection. In a retrospective cohort we assessed whether individual non-lineage defining mutations and overall genomic variation (including low frequency alleles) were associated…

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Overall and Telehealth Addiction Treatment Utilization by Age, Race, Ethnicity, and Socioeconomic Status in California After COVID-19 Policy Changes

Addiction treatment rapidly transitioned to a primarily telehealth modality (telephone and video) during the COVID-19 pandemic, raising concerns about disparities in utilization. To examine whether there were differences in overall and telehealth addiction treatment utilization after telehealth policy changes during…

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Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19-Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults – VISION Network, Nine States, September-November 2022

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated…

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COVID-19 Vaccine Safety Surveillance in Early Pregnancy in the United States: Design Factors Affecting the Association Between Vaccine and Spontaneous Abortion

In the Vaccine Safety Datalink (VSD), we previously reported no association between COVID-19 vaccination in early pregnancy and spontaneous abortion (SAB). The current study aims to understand how time since vaccine roll-out or other methodologic factors could affect results. Using…

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Opportunities for understanding the COVID-19 pandemic and child health in the United States: the Environmental influences on Child Health Outcomes (ECHO) program

Ongoing pediatric cohort studies offer opportunities to investigate the impact of the COVID-19 pandemic on children's health. With well-characterized data from tens of thousands of US children, the Environmental influences on Child Health Outcomes (ECHO) Program offers such an opportunity.…

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Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19-Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults – VISION Network, Nine States, September-November 2022

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated…

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Effectiveness of COVID-19 mRNA Vaccines Against COVID-19-Associated Hospitalizations Among Immunocompromised Adults During SARS-CoV-2 Omicron Predominance – VISION Network, 10 States, December 2021-August 2022

Persons with moderate-to-severe immunocompromising conditions might have reduced protection after COVID-19 vaccination, compared with persons without immunocompromising conditions (1-3). On August 13, 2021, the Advisory Committee on Immunization Practices (ACIP) recommended that adults with immunocompromising conditions receive an expanded primary…

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Trends in Diabetes Screening, Risk Factors and Incidence Before and After the SARS-CoV-2 Pandemic Between the California Medi-Cal and Commercially-Insured Populations

Using quasi-experimental research methods, this study is assessing the extent to which disparities in type 2 diabetes prevention and outcomes were exacerbated during the coronavirus disease 2019 (COVID-19) pandemic between the Medi-Cal and commercially-insured populations. The career development plan for…

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Estimation of COVID-19 mRNA Vaccine Effectiveness Against Medically Attended COVID-19 in Pregnancy During Periods of Delta and Omicron Variant Predominance in the United States

Pregnant people are at high risk for severe COVID-19 but were excluded from mRNA vaccine trials; data on COVID-19 vaccine effectiveness (VE) are needed. To evaluate the estimated effectiveness of mRNA vaccination against medically attended COVID-19 among pregnant people during…

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Effectiveness of 2, 3, and 4 COVID-19 mRNA Vaccine Doses Among Immunocompetent Adults During Periods when SARS-CoV-2 Omicron BA.1 and BA.2/BA.2.12.1 Sublineages Predominated – VISION Network, 10 States, December 2021-June 2022

The Omicron variant (B.1.1.529) of SARS-CoV-2, the virus that causes COVID-19, was first identified in the United States in November 2021, with the BA.1 sublineage (including BA.1.1) causing the largest surge in COVID-19 cases to date. Omicron sublineages BA.2 and…

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Effectiveness of Homologous and Heterologous COVID-19 Booster Doses Following 1 Ad.26.COV2.S (Janssen [Johnson & Johnson]) Vaccine Dose Against COVID-19-Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults – VISION Network, 10 States, December 2021-March 2022

CDC recommends that all persons aged ≥18 years receive a single COVID-19 vaccine booster dose ≥2 months after receipt of an Ad.26.COV2.S (Janssen [Johnson & Johnson]) adenovirus vector-based primary series vaccine; a heterologous COVID-19 mRNA vaccine is preferred over a…

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Effectiveness of COVID-19 Pfizer-BioNTech BNT162b2 mRNA Vaccination in Preventing COVID-19-Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Nonimmunocompromised Children and Adolescents Aged 5-17 Years – VISION Network, 10 States, April 2021-January 2022

The efficacy of the BNT162b2 (Pfizer-BioNTech) vaccine against laboratory-confirmed COVID-19 exceeded 90% in clinical trials that included children and adolescents aged 5-11, 12-15, and 16-17 years (1-3). Limited real-world data on 2-dose mRNA vaccine effectiveness (VE) in persons aged 12-17…

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Waning 2-Dose and 3-Dose Effectiveness of mRNA Vaccines Against COVID-19-Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults During Periods of Delta and Omicron Variant Predominance – VISION Network, 10 States, August 2021-January 2022

CDC recommends that all persons aged ≥12 years receive a booster dose of COVID-19 mRNA vaccine ≥5 months after completion of a primary mRNA vaccination series and that immunocompromised persons receive a third primary dose.* Waning of vaccine protection after…

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Effectiveness of a Third Dose of mRNA Vaccines Against COVID-19-Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults During Periods of Delta and Omicron Variant Predominance – VISION Network, 10 States, August 2021-January 2022

Estimates of COVID-19 mRNA vaccine effectiveness (VE) have declined in recent months (1,2) because of waning vaccine induced immunity over time,* possible increased immune evasion by SARS-CoV-2 variants (3), or a combination of these and other factors. CDC recommends that…

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Contributions of COVID-19 Pandemic-Related Stressors to Racial and Ethnic Disparities in Mental Health During Pregnancy

This study aimed to identify racial and ethnic disparities in prenatal mental health and identify COVID-19 pandemic-related health/healthcare and economic contributors to these disparities, using an established framework for disparity investigation. This cross-sectional study includes 10,930 pregnant people at Kaiser…

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Association of the COVID-19 Pandemic With Routine Childhood Vaccination Rates and Proportion Up to Date With Vaccinations Across 8 US Health Systems in the Vaccine Safety Datalink

The COVID-19 pandemic has affected routine vaccine delivery in the US and globally. The magnitude of these disruptions and their association with childhood vaccination coverage are unclear. To compare trends in pediatric vaccination before and during the pandemic and to…

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Laboratory-Confirmed COVID-19 Among Adults Hospitalized with COVID-19-Like Illness with Infection-Induced or mRNA Vaccine-Induced SARS-CoV-2 Immunity – Nine States, January-September 2021

Previous infection with SARS-CoV-2 (the virus that causes COVID-19) or COVID-19 vaccination can provide immunity and protection from subsequent SARS-CoV-2 infection and illness. CDC used data from the VISION Network* to examine hospitalizations in adults with COVID-19-like illness and compared…

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Effectiveness of 2-Dose Vaccination with mRNA COVID-19 Vaccines Against COVID-19-Associated Hospitalizations Among Immunocompromised Adults – Nine States, January-September 2021

Immunocompromised persons, defined as those with suppressed humoral or cellular immunity resulting from health conditions or medications, account for approximately 3% of the U.S. adult population (1). Immunocompromised adults are at increased risk for severe COVID-19 outcomes (2) and might…

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COVID-19 Vaccination and Non-COVID-19 Mortality Risk – Seven Integrated Health Care Organizations, United States, December 14, 2020-July 31, 2021

By September 21, 2021, an estimated 182 million persons in the United States were fully vaccinated against COVID-19.* Clinical trials indicate that Pfizer-BioNTech (BNT162b2), Moderna (mRNA-1273), and Janssen (Johnson & Johnson; Ad.26.COV2.S) vaccines are effective and generally well tolerated (1-3).…

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Interim Estimates of COVID-19 Vaccine Effectiveness Against COVID-19-Associated Emergency Department or Urgent Care Clinic Encounters and Hospitalizations Among Adults During SARS-CoV-2 B.1.617.2 (Delta) Variant Predominance – Nine States, June-August 2021

Data on COVID-19 vaccine effectiveness (VE) since the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, became the predominant circulating strain in the United States are limited (1-3). CDC used the VISION Network* to examine medical encounters (32,867)…

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Use of COVID-19 Vaccines After Reports of Adverse Events Among Adult Recipients of Janssen (Johnson & Johnson) and mRNA COVID-19 Vaccines (Pfizer-BioNTech and Moderna): Update from the Advisory Committee on Immunization Practices – United States, July 2021

In December 2020, the Food and Drug Administration (FDA) issued Emergency Use Authorizations (EUAs) for Pfizer-BioNTech and Moderna COVID-19 vaccines, and in February 2021, FDA issued an EUA for the Janssen (Johnson & Johnson) COVID-19 vaccine. After each EUA, the…

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COVID-19 Vaccination Coverage Among Insured Persons Aged ≥16 Years, by Race/Ethnicity and Other Selected Characteristics – Eight Integrated Health Care Organizations, United States, December 14, 2020-May 15, 2021

COVID-19 vaccination is critical to ending the COVID-19 pandemic. Members of minority racial and ethnic groups have experienced disproportionate COVID-19-associated morbidity and mortality (1); however, COVID-19 vaccination coverage is lower in these groups (2). CDC used data from CDC's Vaccine…

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Multisystem inflammatory syndrome in children and adults (MIS-C/A): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term "Multisystem Inflammatory Syndrome in Children and Adults (MIS-C/A)" to be utilized in the evaluation of adverse events following immunization. The case definition was developed by topic experts convened by the…

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Rationale and Design of the Pragmatic Randomized Trial of Icosapent Ethyl for High Cardiovascular Risk Adults (MITIGATE)

The MITIGATE study aims to evaluate the real-world clinical effectiveness of pre-treatment with icosapent ethyl (IPE), compared with usual care, on laboratory-confirmed viral upper respiratory infection (URI)-related morbidity and mortality in adults with established atherosclerotic cardiovascular disease (ASCVD). IPE is…

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mHealth Mindfulness Intervention for Women with Moderate-to-Moderately-Severe Antenatal Depressive Symptoms: a Pilot Study Within an Integrated Health Care System

Traditional mindfulness-based interventions have been shown to reduce depression symptoms in pregnant women, although in-person classes may pose significant accessibility barriers, particularly during the COVID-19 pandemic. Mobile technology offers greater convenience, but little is known regarding the efficacy of self-paced,…

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Changes in Diagnostic and Demographic Characteristics of Patients Seeking Mental Health Care During the Early COVID-19 Pandemic in a Large, Community-Based Health Care System

The early COVID-19 pandemic resulted in great psychosocial disruption and stress, raising speculation that psychiatric disorders may worsen. This study aimed to identify patients vulnerable to worsening mental health during the COVID-19 pandemic. This retrospective observational study used electronic health…

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Management of Renin-Angiotensin-Aldosterone System blockade in patients admitted to hospital with confirmed coronavirus disease (COVID-19) infection (The McGill RAAS-COVID- 19): A structured summary of a study protocol for a randomized controlled trial

The aim of the RAAS-COVID-19 randomized control trial is to evaluate whether an upfront strategy of temporary discontinuation of renin angiotensin aldosterone system (RAAS) inhibition versus continuation of RAAS inhibition among patients admitted with established COVID-19 infection has an impact…

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A Multicenter, Randomized, Placebo-controlled Pragmatic Phase 3 Study Investigating the Efficacy and Safety of Rivaroxaban to Reduce the Risk of Major Venous and Arterial Thrombotic Events in Medically Ill Outpatients with Acute Symptomatic COVID-19 (PRE

This virtual, pragmatic randomized clinical trial will evaluate whether rivaroxaban reduces the risk of a composite endpoint of major venous and arterial thrombotic events, all-cause hospitalization, and all-cause mortality compared with placebo in outpatients with acute, symptomatic COVID-19 infection.

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Treatment for Anxiety and Substance Use Disorders During the COVID-19 Pandemic: Challenges and Strategies

: The COVID-19 pandemic is likely to exacerbate existing anxiety and substance use disorders (SUDs) and increase vulnerability among individuals previously free of these conditions. Numerous pandemic-related stressors-coronavirus infection fears, social distancing and isolation, activity restrictions, financial insecurity and unemployment,…

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Acute Emergency Care and Outcomes for Stroke, Myocardial Infarction, and Surgery During the COVID-19 Pandemic in Kaiser Permanente Northern California: Implications for Care Delivery During COVID-19 Recovery Phase and Future Surges

The decreased trend in patients seeking care for acute stroke, acute MI, and acute surgical presentations during the COVID-19 pandemic is concerning for potential long-term morbidity, mortality, rehabilitation costs, and preventable downstream health care utilization. We aim to assess the…

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Sacubitril/Valsartan in Advanced Heart Failure With Reduced Ejection Fraction: Rationale and Design of the LIFE Trial

The PARADIGM-HF (Prospective Comparison of Angiotensin II Receptor Blocker Neprilysin Inhibitor With Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial reported that sacubitril/valsartan (S/V), an angiotensin receptor-neprilysin inhibitor, significantly reduced mortality and heart failure…

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Pilot pragmatic randomized trial of mHealth mindfulness-based intervention for advanced cancer patients and their informal caregivers

Assess the feasibility of conducting a cluster randomized trial (RCT) comparing technology-delivered mindfulness-based intervention (MBI) programs against a waitlist control arm targeting advanced cancer patients and their informal caregivers. Two-arm cluster RCT within Kaiser Permanente Northern California (KPNC). We recruited…

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SARS-CoV-2 Infection Among Hospitalized Pregnant Women: Reasons for Admission and Pregnancy Characteristics – Eight U.S. Health Care Centers, March 1-May 30, 2020

Pregnant women might be at increased risk for severe coronavirus disease 2019 (COVID-19), possibly related to changes in their immune system and respiratory physiology* (1). Further, adverse birth outcomes, such as preterm delivery and stillbirth, might be more common among…

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Obesity and Mortality Among Patients Diagnosed With COVID-19: Results From an Integrated Health Care Organization

Obesity, race/ethnicity, and other correlated characteristics have emerged as high-profile risk factors for adverse coronavirus disease 2019 (COVID-19)-associated outcomes, yet studies have not adequately disentangled their effects. To determine the adjusted effect of body mass index (BMI), associated comorbidities, time,…

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COVID-19 Response Grant

Adults with intellectual or developmental disabilities may be especially impacted by the ways the COVID-19 pandemic has led to drastic changes in usual daily routines and the way healthcare encounters have been transitioned to virtual (video, telephone) visits. This project…

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Incidence, clinical outcomes, and transmission dynamics of severe coronavirus disease 2019 in California and Washington: prospective cohort study

To understand the epidemiology and burden of severe coronavirus disease 2019 (covid-19) during the first epidemic wave on the west coast of the United States. Prospective cohort study. Kaiser Permanente integrated healthcare delivery systems serving populations in northern California, southern…

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