July 9, 2026

Influenza

Influenza Vaccine Effectiveness Against Pediatric Death in the United States: 2016–2025
Investigators conducted a case-cohort analysis comparing current season influenza vaccination status among reported influenza-associated pediatric deaths with survey estimates of influenza vaccination coverage in pediatric age groups. Underlying medical conditions and current seasonal influenza vaccination were obtained from surveillance case reports. They estimated vaccination odds ratios (OR) and 95% CIs from logistic regression comparing influenza vaccination among children who died with vaccination coverage in comparison cohorts. Vaccine effectiveness (VE) was calculated as (1 - OR) × 100. From August 2016 through July 2025, 1,234 laboratory-confirmed influenza-associated pediatric deaths were reported among children aged 6 months to 17 years. Of 1,086 reported deaths with influenza vaccination information, 124 (23%) of 530 children with underlying medical conditions and 70 (13%) of 556 children without known conditions were fully vaccinated against influenza. Average influenza vaccination coverage in survey cohorts was 49%. VE was 80% (95% CI 75–84) overall, 77% (95% CI 71–82) among children with underlying medical conditions and 87% (95% CI 84–89) among children without known conditions. Conclusion: Influenza vaccination reduced risk of fatal influenza among children with or without known underlying medical conditions.

COVID: Early Viral Phase

Nirmatrelvir/Ritonavir for the Treatment of COVID-19 in Children Aged 6 Years and Older
This ongoing Phase 2/3 interventional, open-label study evaluated nirmatrelvir/ritonavir (NMV/r) in pediatric participants with mild-to-moderate COVID-19 at risk for severe disease (due to underlying medical conditions). Twice daily (BID) oral NMV/r was administered for 5 days to participants aged at least 6 years weighing at least 40 kg (Cohort 1) or 20 to <40 kg (Cohort 2). Overall, 75 participants received at least 1 dose. Simulated exposure of NMV/r 300/100 mg BID for Cohort 1 and 150/100 mg BID for Cohort 2 indicated more than 90% of participants achieved minimum NMV concentrations above the 90% effective concentration after dose 1 and at steady state. NMV/r was safe and well tolerated. The most frequently reported adverse events (AEs) were diarrhea and headache (n = 3 [4%] participants each). No discontinuations because of treatment-related AEs occurred. No treatment-related serious AEs were reported. No COVID-19−related hospitalizations or all-cause deaths were reported. Robust reductions in SARS-CoV-2 RNA from baseline to the end of treatment were observed.

COVID: The Late Phase/PASC/Long COVID

Efficacy and Safety of Rivaroxaban, Colchicine, and Famotidine–Loratadine with Specialist Supportive Clinical Care for Fatigue in Patients with Post-COVID-19 Condition in the UK: A Multisite, Open-label, Randomised Controlled Trial
These are the results of a Phase 3, four-group, randomised, controlled, adaptive platform, open-label drug trial nested within a pragmatic, multicentre, cluster-randomised trial of an integrated care pathway (ICP) for Long COVID across 12 UK National Health Service (NHS) specialist Long COVID care clinics in the UK. Participants had to be adults (>18 years) with Long COVID who had not been hospitalised with COVID-19. The 6,035 eligible participants were randomly assigned (1:1:1:1) to receive colchicine 500 μg twice daily, rivaroxaban 10 mg once daily, famotidine 40 mg with loratadine 10 mg once daily, or no drug for 12 weeks. The primary endpoint was 12-week fatigue, assessed with the Fatigue Assessment Scale. Adjusted analyses showed small, statistically significant FAS reductions in the colchicine (–1·49 points [95% CI –2·92 to –0·06], p=0·041) and famotidine–loratadine (–1·48 points [–2·88 to –0·08], p=0·038) groups, but not in the rivaroxaban group (–1·06 points [–2·47 to 0·35, p=0·139), compared with no study drug at 12 weeks. However, 24-week FAS scores, 12 weeks after drug cessation, were not significantly different between groups. Treatment was well tolerated. In participants with long COVID, severe fatigue reduced in all study groups—including the no drug group—over 12 weeks, with small additional reductions in the colchicine and famotidine–loratadine groups compared with the no drug group. Modest effects on FAS were not sustained after drug withdrawal.

Long-term Sequelae Associated With Severe West Nile Virus Disease in Maricopa County, Arizona, 2021
A total of 159 patients with West Nile Virus (WNV) disease and 75 patients with predominantly COVID-19 and coccidioidomycosis completed standardized assessment tools Among patients with WNV, 40% were transferred to long-term care facilities, and 83% experienced ongoing symptoms, including fatigue, myalgia, arthralgia, pain, and problems with sleep, memory, and concentration. Overall, 33% reported disabilities and 55% reported worse health than before illness. Long-term sequelae in patients hospitalized with WNV were common up to two years after hospitalization, but similar findings to comparators suggest there might be common inflammatory or other physiologic pathways leading to post infectious sequelae or outcomes related to hospitalization. Providers caring for patients hospitalized with WNV should make patients and caregivers aware of the prolonged and possible incomplete recovery process.