Effectiveness of Bivalent mRNA COVID-19 Vaccines in Preventing COVID-19-Related Thromboembolic Events Among Medicare Enrollees Aged ≥65 Years and Those with End Stage Renal Disease - United States, September 2022-March 2023.

COVID-19 has been associated with an increased risk for thromboembolic events, including ischemic stroke, venous thromboembolism, and myocardial infarction. Studies have reported lower rates of COVID-19-related thromboembolic events among persons who received the COVID-19 vaccine compared with persons who did not, but rigorous estimates of vaccine effectiveness (VE) in preventing COVID-19-related thromboembolic events are lacking. This analysis estimated the incremental benefit of receipt of a bivalent mRNA COVID-19 vaccine after receiving an original monovalent COVID-19 vaccine. To estimate VE of a bivalent mRNA COVID-19 dose in preventing thromboembolic events compared with original monovalent COVID-19 vaccine doses only, two retrospective cohort studies were conducted among Medicare fee-for-service enrollees during September 4, 2022-March 4, 2023. Effectiveness of a bivalent COVID-19 vaccine dose against COVID-19-related thromboembolic events compared with that of original vaccine alone was 47% (95% CI = 45%-49%) among Medicare enrollees aged ≥65 years and 51% (95% CI = 39%-60%) among adults aged ≥18 years with end stage renal disease receiving dialysis. VE was similar among Medicare beneficiaries with immunocompromise: 46% (95% CI = 42%-49%) among adults aged ≥65 years and 45% (95% CI = 24%-60%) among those aged ≥18 years with end stage renal disease. To help prevent complications of COVID-19, including thromboembolic events, adults should stay up to date with COVID-19 vaccination.

Race, ethnicity, and immune tolerance induction in hemophilia A in the United States.

Background: In racially diverse communities, treatment of chronic diseases can vary across racial and ethnic groups. Objectives: To examine healthcare disparities in hemophilia care in the United States by evaluating receipt of immune tolerance induction (ITI) among different racial and ethnic groups. Methods: In this cross-sectional study, people with severe hemophilia A with an inhibitor who entered the Center for Disease Control and Prevention Community Counts registry between 2013 and 2017, were aged ≥5 years at study entry, and had a history of an inhibitor (n = 614) were included. The proportion of participants receiving ITI was examined according to race and ethnicity in bivariable analysis and multivariable analysis adjusting for demographic and clinical covariates. Unadjusted and adjusted prevalence ratios and corresponding 95% CIs were computed. Results: Among 614 participants included in the study, 56.4% were non-Hispanic (NH) White, 19.7% were NH Black, 18.4% were Hispanic, and 4.9% were Asian. ITI was received by 85.2% of participants. On bivariable analysis, ITI treatment did not vary by race or ethnicity. On multivariable analysis, NH Black and Hispanic participants were significantly less likely to receive ITI compared to NH White participants (adjusted prevalence ratio, 0.91 [95% CI, 0.84-0.99] and 0.84 [95% CI, 0.75-0.93], respectively). Conclusion: Although the role of ITI may evolve with growing use of emicizumab and the introduction of new hemophilia treatment products, understanding characteristics that influence care, particularly race and ethnicity, where physician bias and patient mistrust can occur, will remain relevant and applicable to other complex therapies, including gene therapy.

Influenza vaccination rates and hospitalizations among Medicaid enrollees with and without sickle cell disease, 2009-2015.

BACKGROUND: Personswith sickle cell disease (SCD) face increased risks for pulmonary and infection-related complications. This study examines influenza vaccination coverage and estimates influenza-related morbidity among Medicaid enrollees with and without SCD. PROCEDURE: Influenza vaccination coverage and hospitalizations related to influenza and pneumonia/acute chest syndrome (ACS) during each influenza season from 2009-2010 to 2014-2015 were assessed among enrollees in the IBM MarketScan® Multi-State Medicaid Database. Enrollees with SCD were identified as enrollees with greater than or equal to three claims listing SCD within a 5-year period during 2003-2017. Vaccinations were identified in outpatient claims. Hospitalizations associated with influenza or pneumonia/ACS were identified using inpatient claims. This study includes a series of cross-sectional assessments by season. RESULTS: From 2009-2010 through 2014-2015 seasons, the SCD sample ranged from 5044 to 8651 enrollees; the non-SCD sample ranged from 1,841,756 to 3,796,337 enrollees. Influenza vaccination coverage was higher among enrollees with SCD compared with enrollees without SCD for all seasons (24.5%-33.6% and 18.2%-22.0%, respectively). Age-standardized rates of influenza-related hospitalizations were 20-42 times higher among SCD enrollees compared with non-SCD enrollees, and ACS/pneumonia hospitalizations were 18-29 times higher. Among enrollees with SCD, influenza-related hospitalization rates were highest among children aged 0-9 years. Among enrollees without SCD, influenza-related hospitalization rates were highest among adults aged 40-64 years. CONCLUSIONS: Although vaccine coverage was higher in persons with versus without SCD, efforts to increase influenza coverage further are warranted for this high-risk group, who experienced markedly higher rates of influenza and ACS/pneumonia hospitalizations during each season.