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Cumulative Incidence and Prevalence of Autism Spectrum Disorder
Prospective population-based screening and diagnostic assessment was conducted in 12 consecutive birth cohorts in South Korea among children born from January 1998 to December 2010 and ascertained at age 7 years between January 2005 and December 2017. All children aged 7 years entering elementary schools constituted the target population. Among more than 62,000 children, 2,077 screened positive and were invited for detailed evaluation, and 881 completed comprehensive diagnostic assessments. Data were analyzed from January 2024 to July 2026. Across consecutive birth cohorts, both 7-year cumulative incidence and prevalence estimates of ASD at age 7 years remained stable, ranging from 1.9% (95% CI, 1.5-2.4) to 3.2% (95% CI, 2.7-3.8) for incidence and from 2.0% (95% CI, 1.5-2.6) to 3.4% (95% CI, 2.7-4.0) for prevalence, with no statistically significant increase or decrease. Female children with ASD were disproportionately represented among previously undiagnosed cases identified in general education settings and exhibited distinct phenotypic profiles and substantial unmet clinical needs. The findings from this cohort study suggest that detection-related factors may contribute substantially to reported increases in ASD occurrence estimates. Interpretation of changes in ASD occurrence estimates should account for methodological differences, changing service-use patterns, and ascertainment context in service-based surveillance systems.
Immunogenicity and Safety of an MF59-adjuvanted Cell-derived Higher-dose Quadrivalent Influenza Vaccine (aQIVc) in Adults Aged 50 Years or Older: A Phase 3 Randomised Controlled Trial
This multicentre study randomly assigned (3:2:2) healthy adults aged 50 years or older to a MF59-adjuvanted cell-derived quadrivalent influenza vaccine (aQIVc), MF59-adjuvanted egg-derived quadrivalent influenza vaccine, (aQIV), or recombinant quadrivalent influenza vaccine (QIVr) via an interactive response technology system, using a permuted block randomisation method (block size of seven), with stratification by age group (50–64 or ≥65 years), history of any influenza vaccination (previous three influenza seasons), and study site. aQIVc contains haemagglutinin (HA; 45 μg per strain) and MF59 (19·5 mg squalene); aQIV contains 15 μg HA per strain and MF59 (9·75 mg squalene); and QIVr contains 45 μg HA per strain. Participants received one vaccine dose (day 1; intramuscular injection). Primary immunogenicity objectives were lot-to-lot consistency of three batches of aQIVc (met if the 95% CI of the day-29 geometric mean titre [GMT] ratios was 0·67–1·5 for the pairwise comparison of each vaccine strain) and non-inferiority of aQIVc versus aQIV and QIVr (met if the lower bound 97·5% CI for day-29 GMT ratio and seroconversion rate differences were 0·67 or higher and –10% or higher, respectively, per strain) in the per-protocol set. In adults aged 50 years or older, aQIVc was non-inferior and superior to aQIV for all four influenza strains and non-inferiority criteria for aQIVc versus QIVr were met for A/H1N1 and both B strains, but not A/H3N2. No safety concerns were identified.
Baseline Interferon Signaling in Monocytes and Antibody-mediated Innate Activation are Associated with Reactogenicity to mRNA Vaccines
One of the barriers to vaccine uptake is reactogenicity, where vaccination induces transient pain and systemic symptoms, a problem that became particularly evident during COVID-19 vaccination campaigns despite affecting only a fraction of the population. Here, authors aimed to tease apart the drivers of this reactogenicity using samples from COVID-19 vaccine recipients and animal models, finding that monocytes and vaccine-induced antibodies at the injection site, as well as early interferon-γ production by T cells, drove early inflammatory responses associated with reactogenicity. Moreover, individuals with a higher baseline interferon response signature in monocytes were more likely to have systemic symptoms after vaccination. These data point to both mechanistic drivers and potential baseline biomarkers of reactogenicity, providing a framework to potentially reduce vaccine side effects and predict who might be most likely to develop them.
Loss of Vesicular Monoamine Transporter 2 in Striatum of Long COVID and Relationship to Neuropsychiatric Symptoms
This case–control study (Aug 2022–Apr 2025, Toronto, Canada) included 24 adults with Long COVID and 24 age-matched healthy controls, and the healthy control sample was extended to 43 for exploratory analyses. Primary outcome was comparison of (+)[11C]DTBZ binding potential (BPND), PET measure of VMAT2 binding, between Long COVID and control groups across ventral striatum, dorsal putamen, and dorsal caudate. Secondary outcomes were associations of regional (+)[11C]DTBZ BPND with neuropsychiatric measures (apathy, anhedonia, motor retardation) in long COVID. Findings show (+)[11C]DTBZ BPND was significantly lower in 24 individuals with Long COVID vs 24 age-matched healthy controls (linear mixed effects model, P = 4 × 10−5; vs 43 controls, P = 6 × 10−4). Apathy, motor slowing (secondary outcomes) and memory decline (exploratory outcome) correlated with lower (+)[11C]DTBZ BPND in ventral striatum, dorsal putamen and caudate, respectively (|r| = 0.48–0.58, P = 0.0029–0.018). Findings of reduced VMAT2 binding may reflect reduced dopaminergic terminal integrity in Long COVID. Loss of dopamine nerve terminals may be contributing to symptom correlates of apathy, motor slowing and memory decline suggesting improved function of dopaminergic synapses as a new therapeutic direction to treat Long COVID.
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COVID-19 in US and Canada
