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Herpes Zoster Vaccination and Incident Dementia in Canada: An Analysis of Natural Experiments
Authors extracted data on 464,637 patients who were registered with a primary care provider in the CPCSSN as of Sept. 15, 2016. Of 232,124 patients born in Ontario included in the analysis, 125,719 (54·2%) were female, 106,354 (45·8%) were male, and 51 (<0·5%) had missing information on sex. Patients born immediately before versus immediately after the two eligibility thresholds for herpes zoster vaccination did not differ in their health characteristics at the time of the start date of the vaccination program, except for a large difference in their probability of receiving herpes zoster vaccination. Being born immediately before versus immediately after Jan. 1, 1946, decreased the probability of receiving a new dementia diagnosis by an absolute difference of 2·0 percentage points (95% CI 0·4–3·5, p=0·012) over a 5·5-year follow-up. Using the Jan. 1, 1945, threshold, dementia diagnoses were also reduced by 2·0 percentage points (0·2–3·8, p=0·025) over 5·5 years. After the start of the program, new dementia diagnoses among the birth cohorts eligible for herpes zoster vaccination in Ontario were significantly less common than in the same birth cohorts in other Canadian provinces that did not have a herpes zoster vaccination program.
Estimated Effectiveness of 2024-2025 COVID-19 Vaccination Against Severe COVID-19
In this case-control study of 1888 adults with COVID-19 and 6605 adults without COVID-19, estimated VE was 40% against hospitalization and 79% against invasive mechanical ventilation or death. The estimated VE was similar for KP.3.1.1 and XEC lineages, as well as for spike protein mutations potentially associated with immune evasion (S31 deletion, T22N and F59S substitutions). Findings suggest that COVID-19 vaccines offered protection against hospitalization and severe in-hospital outcomes during the 2024-2025 season, in which multiple JN.1 lineages evolved and circulated.
Long COVID Associated with SARS-CoV-2 Reinfection Among Children and Adolescents in the Omicron Era (RECOVER-EHR): A Retrospective Cohort Study
This study used data from 40 children's hospitals and health institutions in the USA participating in the Researching COVID to Enhance Recovery (RECOVER) Initiative. Authors identified 407,300 (87·5%) of 465,717 eligible children and adolescents with a first infection episode and 58,417 (12·5%) with a second infection episode from Jan 1, 2022, to Oct 13, 2023, in the RECOVER database. 233,842 (50·2%) patients were male and 231,875 (49·8%) were female. The mean age was 8·17 years (SD 6·58). The incident rate of PASC diagnosis (U09.9) per million people per six months was 903·7 (95% CI 780·9–1026·5) in the first infection group and 1883·7 (1565·1–2202·3) in the second infection group. Reinfection was associated with a significantly increased risk of an overall PASC diagnosis (U09.9) (RR 2·08 [1·68–2·59]) and a range of symptoms and conditions potentially related to PASC (RR range 1·15–3·60). These findings add to previous evidence linking paediatric Long COVID to multisystem effects and highlight the need to promote vaccination in younger populations and support ongoing research to better understand PASC, identify high-risk subgroups, and improve prevention and care strategies.
Early Administration of Neutralising Monoclonal Antibodies and Post-acute Sequelae of COVID-19
Using national COVID-19 registries and healthcare claims data, this group conducted a retrospective cohort study including all Singaporeans who were unvaccinated, partially vaccinated, or immunocompromised at the time of SARS-CoV-2 infection between July 2021 and December 2022. Individuals were stratified by receipt of mAbs. Of 19,689 eligible hospitalised individuals, 6.9% received early mAb therapy. While mAb treatment had no significant impact on overall post-acute sequelae (aHR for any sequelae:1.26[0.98–1.63]), they observed an increased risk of autoimmune diseases (aHR=2.20[1.22–3.97]), particularly systemic lupus erythematosus and rheumatoid arthritis). There was also elevated risk of deep venous thrombosis (aHR=1.83[1.03-3.22]).
New Review Highlights Growing Evidence that Diabetes Drug Metformin Can Prevent Long COVID
Multiple randomized clinical trials and analyses of electronic health records (EHRs) suggest that metformin, a widely available diabetes drug, may reduce the risk of developing Long COVID when taken during or shortly after acute COVID-19 infection, according to a literature review. The review, written by University of Minnesota Medical School researchers Carolyn T. Bramante, MD, MPH, and David R. Boulware, MD, MPH, was commissioned to comment on a recent population-based cohort study by Ubonphan Chaichana, MSc, and colleagues and to situate the findings within a widening body of evidence that suggests metformin use during COVID infection can substantially reduce the risk of developing Long COVID. The authors emphasize that none of the studies examined metformin as a treatment for already-established long COVID. Rather, they focused on prevention and whether use of the drug during acute infection could reduce the likelihood of developing persistent post-COVID symptoms.
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