April 23, 2026

RSV

Maternal RSV Vaccination and Reduced Risk of Hospitalisation for Babies in England, 2024/25
Bivalent PreF maternal vaccination against respiratory syncytial virus (RSV) was introduced in England on 1 September 2024 for pregnant women from 28 weeks’ gestation. Here they used linkage of routine datasets to build a retrospective cohort and study the association of vaccination with rates of RSV-associated lower respiratory tract infection (LRTI) hospitalisation in infants between September 2024 and March 2025. Vaccine effectiveness (VE) was estimated at 81.3% (95% CI: 78.9, 83.4) in the fully vaccinated group. In cases with 10 to 13 days between vaccination and birth, VE was 50.0% (36.4, 61.4). VE reached 84.9% (82.3, 87.2) if received at least 28 days before birth.

Viral Dynamics of the Respiratory Syncytial Virus During Experimental Human Challenge: Insights for Transmission and Protection
Authors analyzed high-resolution viral, immunological and clinical data from 225 adults experimentally infected by RSV with mathematical models developed to characterize RSV host-pathogen interaction. Infectious virus was detected three days post-exposure (dpe) (90% PI: 2-5 dpe), and cleared by 8 dpe (90% PI: 6-11 dpe), defining a median window of detectable infectious virus shedding of approximately 5 dpe (90% PI: 3.5-10 dpe). In contrast, viral RNA persisted longer, with a median clearance time of 12 days (90% PI: 9-15 dpe). The analysis of clinical evolution showed a significant association between the occurrence of symptoms and viral dynamics. While pauci-symptomatic individuals represented 35% of the population, they accounted for only ∼ 5% of infectious viral shedding.

COVID: Active Vaccination/Immunity

Clinical and Economic Benefits of Seasonal COVID-19 Vaccination in Germany: Results from the ROUTINE-COV19 Study, September 2022 to March 2024
In Germany, COVID-19 vaccinations were integrated into routine care and thereby included in the statutory health insurance records in April 2023, allowing real-world clinical and economic assessment. Authors wanted to analyse the impact of autumn COVID-19 vaccinations following integration into routine care, using data from adults aged ≥ 18 years insured in the federal states of Saxony and Thuringia between September 2022 and March 2024. COVID-19-vaccinated individuals experienced lower hospitalisation rates associated with COVID-19, respiratory or cardiovascular diseases, as well as reduced all-cause mortality and long COVID diagnoses. This translated to lower healthcare costs and fewer sick leave days compared with unvaccinated individuals, with estimated savings of ca EUR 1 million in inpatient care and EUR 1.3 million in indirect costs caused by sick leave in the 4-month follow-up period.. These results support the sustained implementation of national vaccination recommendations and provide evidence to guide policy decisions in Germany and other countries with similar healthcare systems.

COVID: Early Viral Phase

Effectiveness and Safety of Molnupiravir among Patients with Mild to Moderate COVID-19: A Prospective, Observational, Cohort Study
These are the results of a study that included all mild adult COVID-19 cases for whom molnupiravir was recommended at healthcare institutions in two cities in Türkey from 29.03.2022 to 29.09.2023. During the early and late phases of the study, Omicron B.A.2.75 and XBB.1 were the circulating variants, respectively. The primary outcome was hospitalization, death or new oxygen need due to COVID-19 within 28 days of follow-up. The effects of molnupiravir on viral clearance, serum biochemical tests and SARS-CoV-2 antibody levels were also assessed. A total of 844 patients (402 molnupiravir, 442 no molnupiravir) were included. The mean age was 66, 75% of them were vaccinated. The primary outcome occurred in eight patients, with no significant difference between propensity score-matched groups. Molnupiravir showed no effect on clinical improvement. Viral clearance was higher in the molnupiravir group on day three, but higher in the untreated group by day 10. Serum SARS-CoV-2 antibody levels on day 28 were lower in the molnupiravir group. The effectiveness of molnupiravir in reducing hospitalization and death may be insufficient in previously immune COVID-19 patients. Additionally, molnupiravir may reduce day-28 serum SARS-CoV-2 antibody level.

COVID: The Late Phase/PASC/Long COVID

Divergent Inflammatory and Neurology-related Protein Levels in Long COVID Following Primary and Breakthrough SARS-CoV-2 Infections
Background: While persistent inflammation has emerged as an important feature of this condition, it is unclear if immune responses from COVID-19 vaccination or SARS-CoV-2 re-infection exacerbate or mirror the initial inflammatory responses. Authors quantified 182 inflammatory and neurology-related proteins in plasma using multiplexed affinity proteomics. Plasma samples from the COVID PROFILE cohort conducted in Victoria, Australia, were collected 6-9 months after first infection, but before COVID-19 vaccination from individuals who had recovered from COVID-19 (n = 21) or from individuals with long COVID (n = 12). To establish baseline plasma profiles, protein levels were benchmarked against unvaccinated, SARS-CoV-2 naive individuals (n = 24). In addition, they performed longitudinal analysis in a subset of individuals (n = 34), where paired samples collected 2-4 weeks after a third COVID-19 vaccine dose and after SARS-CoV-2 post vaccination infection were available to assess inflammatory and neurology protein plasma levels after antigen exposure in these contexts. They found that the immune signature is different between what is seen with vaccination and what is seen with infection after vaccination.

School Difficulties and Long COVID in Children and Adolescents
In this study cross-sectional data from the NIH-funded Researching COVID to Enhance Recovery (RECOVER) pediatric observational cohort were analyzed to assess associations in school-age children (6 to 11 years) and adolescents (12 to 17 years) between LC and caregiver-reported school-related functional outcomes. LC was defined using RECOVER age group-specific symptom-based LC research indices. The primary outcome was worsening of child grades. Secondary outcomes included difficulty paying attention, limited fun with friends, and having an Individualized Education Program (IEP). The cohort included 1,976 children (406 school-age, 1,570 adolescent). 18% of school-age children and 29% of adolescents with LC had reported worsened grades, compared to 7% and 11% without LC, respectively [school-age: adjusted RR 2.18 (95% CI: 1.15-4.11); adolescent: adjusted RR 2.39 (95% CI: 1.86-3.06)]. In both age groups, children with LC were more likely to have difficulty paying attention, limited fun with friends, and IEPs.