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Hepatitis B Vaccination at Birth: Safety, Effectiveness, and Public Health Benefit
Authors analyzed studies of the epidemiology of HBV infection, clinical trials, systematic reviews, vaccine safety from surveillance and clinical studies, and potential impact of revised ‘restricted’ ACIP/CDC guidelines on individual and public health. They synthesized the history of ACIP recommendations and resulting trends in HBV incidence. The review found strong evidence for the safety and effectiveness of the birth dose, and no improved safety or effectiveness with a delayed first dose. They found no evidence to support use of post-vaccination serology. Infant vaccination has resulted in a 99% reduction in pediatric HBV infections; they found no evidence to support a change in vaccine recommendations but identified potential health consequences.
Influenza Vaccination and the Risk of Myocardial Infarction: A Meta-epidemiology Study
This open-access review systematically searched PubMed, Embase, and the Cochrane Library from inception to July 16, 2025 for cohort and case-control studies examining influenza vaccination and MI. They included fifteen studies (seven cohort studies, seven case-control studies, and one self-controlled case-series) involving 23,484,167 individuals. Influenza vaccination was associated with lower odds of MI compared with no vaccination (OR = 0.82; 95% CI: 0.78–0.86; I² = 65.6%; P < 0.001). Authors state: “While causal inference cannot be established, these findings support the potential role of influenza vaccination in cardiovascular risk prevention and highlight the need for further well-designed studies to clarify the nature and durability of this association.”
Long-term Impact of Nirsevimab on Prevention of Respiratory Syncytial Virus Infection Using a Real-world Global Database
These are the results of a multi-centre retrospective study using a global database (TriNetX). The participants were children under 24 months of age who required nucleic acid testing for RSV between July 2023 and June 2025. Children who received the last dose of nirsevimab within 6 months, between 6 and 11 months, and beyond 12 months were compared with those who did not receive any nirsevimab dose by epidemic season after propensity score matching. A total of 4627, 861, and 532 children aged <24 months who received nirsevimab within 6 months, between 6 and 11 months, and beyond 12 months before RSV testing, respectively, and 210,626 children who did not receive any nirsevimab were identified. Compared with those who did not receive nirsevimab, the odds ratios (OR) of a positive RSV test result among those who received nirsevimab within 6 months, between 6 and 11 months, and beyond 12 months before testing were 0.49 [95% confidence interval (CI) 0.42, 0.57] (p<0.001), 0.67 [0.48, 0.94] (p<0.020), and 1.21 [0.89, 1.65] (p=0.234) in the last epidemic season, respectively.
Choroid Plexus Alterations in Long COVID and Their Associations with Alzheimer's Disease Risks
Choroid plexus (ChP) enlargement is a neuroimaging biomarker of neuroinflammation and neurodegeneration. This study looked at 86 Long COVID, 67 recovered COVID, and 26 COVID-negative healthy controls (HCs). ChP volume and cerebral blood flow (CBF) were quantified, and their associations with Alzheimer's disease (AD) symptoms and plasma biomarkers were examined. Both Long COVID and recovered COVID patient groups showed higher ChP volume and lower CBF than HC. Relative to recovered COVID, Long COVID patients had a larger ChP volume, but no significant difference in CBF. ChP volume correlated positively with glial fibrillary acidic protein (r = 0.35) and phosphorylated tau217 (p-tau217; r = 0.54), while CBF correlated negatively with p-tau217 (r = –0.56). Both ChP volume and CBF were associated with cognitive decline measured with Mini-Mental State Examination and Clinical Dementia Rating.
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COVID-19 in US and Canada
