Daily Respiratory Research Analysis
Analyzed 173 papers and selected 3 impactful papers.
Summary
Three high-impact respiratory studies stand out today: a long-term cluster-randomized evaluation shows that a reduced 1+1 PCV10 schedule sustains vaccine-type carriage control with indirect protection; mechanistic and genomic work links the global rise of pneumococcal serotype 3 clade I-α/CC180 to a LytA mutation that enhances immune evasion; and an automated CT biomarker (e-Lung WRVS) robustly predicts mortality and FVC decline across non-IPF ILDs. Together, they inform vaccine policy, elucidate pathogen escape, and enable imaging-based risk stratification.
Research Themes
- Vaccine schedule optimization and population-level indirect effects
- Pathogen immune evasion and serotype/clonal replacement in pneumococcus
- Automated imaging biomarkers for prognosis in interstitial lung diseases
Selected Articles
1. Sustained and indirect effects of PCV10 reduced-dose schedules on pneumococcal carriage in Viet Nam: a long-term follow-up of a cluster-randomised controlled trial.
In a long-term follow-up of a cluster-randomized PCV10 trial in Viet Nam (n=49,644), the reduced 1+1 infant schedule remained non-inferior to 2+1/3+0 for vaccine-type (VT) carriage at 5.5 years, with VT prevalence in infants of 0.7% (1+1) vs 1.9% (2+1) and 0.9% (3+0). VT carriage proportions fell markedly across infants, toddlers, and unvaccinated adult caregivers, indicating robust herd effects. No serious adverse events were judged vaccine-related.
Impact: This trial provides high-quality evidence that a reduced-dose PCV10 schedule sustains direct and indirect protection, informing global immunization policy and potential cost-saving strategies without compromising effectiveness.
Clinical Implications: Health systems can consider shifting to a 1+1 PCV10 schedule (with appropriate catch-up) to maintain pneumococcal disease control while reducing programmatic complexity and cost, with expectation of herd protection.
Key Findings
- At 5.5 years, 1+1 remained non-inferior to 2+1/3+0 for VT carriage in infants and toddlers (e.g., infants: difference vs 2+1 = -1.2 pp, 95% CI -3.0 to 0.6).
- Marked declines in VT proportion among carriers: infants 52.1%→7.6%, toddlers 50.0%→4.0%, adult caregivers 39.4%→10.5%, indicating herd effects.
- Fifty serious adverse events within 1 month post-vaccination occurred but none were deemed vaccine-related; all children recovered without sequelae.
Methodological Strengths
- Cluster-randomized design with long-term follow-up (5.5 years) and large sample (n=49,644).
- Pre-specified non-inferiority margins and concurrent assessment of indirect effects across age strata.
Limitations
- Findings are most applicable to settings with established PCV programs and catch-up; generalizability to naive settings is uncertain.
- Carriage endpoints, not clinical disease, were primary; linkage to disease outcomes was not directly assessed.
Future Directions: Evaluate clinical disease endpoints and cost-effectiveness of 1+1 schedules across diverse epidemiologic contexts, and monitor serotype replacement dynamics.
BACKGROUND: A cluster-randomised trial in Nha Trang, Viet Nam, previously showed non-inferiority of a reduced two-dose (1p + 1) pneumococcal conjugate vaccine 10 (PCV10) schedule compared with three-dose schedules (2p + 1, 3p + 0) for controlling vaccine-type (VT) nasopharyngeal carriage after 3·5 years, but the long-term sustainability of reduced-dose schedules and their indirect effects on unvaccinated age groups remain incompletely understood. We aimed to assess the sustained and indirect effects of reduced-dose PCV10 schedules on VT carriage 5·5 years after vaccine introduction. METHODS: This study presents long-term follow-up data from a cluster-randomised controlled trial conducted in 24 communes in Nha Trang, Viet Nam. These communes were randomly assigned (1:1:1:1; six communes per group) by automated rejection sampling to one of four PCV10 vaccination schedules for infants: 0p + 1 (single dose at age 12 months), 1p + 1 (doses at ages 2 and 12 months), 2p + 1 (doses at ages 2, 4, and 12 months), or 3p + 0 (doses at ages 2, 3, and 4 months); three unvaccinated communes provided observational comparison. The prespecified primary outcome for this follow-up study was non-inferiority of 1p + 1 versus standard-dose (2p + 1, 3p + 0) schedules for prevalence of VT carriage in vaccine-eligible infants (aged 4-11 months) and toddlers (aged 14-24 months) in 2022 (5·5 years after vaccine introduction. A prespecified secondary objective evaluated the 0p + 1 schedule. Indirect effects on VT carriage prevalence in adult caregivers and preschool children (aged 3-4 years) were also assessed. Non-inferiority was defined as the upper bound of the 95% CI of the difference in VT carriage prevalence not exceeding 5 percentage points (pp). Age-specific trends in VT carriage proportion over the trial period were estimated using Poisson regression models with intervention groups pooled. This trial was completed and is registered with ClinicalTrials.gov, NCT02961231. FINDINGS: Between Oct 10, 2016, and Aug 23, 2022, 49 644 participants were enrolled, including 10 423 infants (aged 4-11 months), 10 988 toddlers (aged 14-24 months), 9580 preschool children (aged 3-4 years), and 18 653 caregivers. Among the 30 991 children, 15 018 (48·5%) were female and 15 973 (51·5%) were male. 27 384 (88·4%) were enrolled in vaccinated communes (0p + 1: 6984, 1p + 1: 6906, 2p + 1: 6972, 3p + 0: 6522) and 3607 (11·6%) in the unvaccinated communes. At 5·5 years, prevalence of PCV10-type carriage in infants was 0·7% (2/286) in the 1p + 1 group, 1·9% (6/314) in the 2p + 1 group, and 0·9% (2/226) in the 3p + 0 group; in toddlers, it was 0·9% (3/332) in the 1p + 1 group, 0·6% (2/344) in the 2p + 1 group, and 1·0% (3/300) in the 3p + 0 group. The 1p + 1 schedule remained non-inferior to three-dose schedules in all infant and toddler comparisons (differences in infants of -1·2 pp [95% CI -3·0 to 0·6] for 1p + 1 vs 2p + 1 and -0·2 pp [-1·7 to 1·4] for 1p + 1 vs 3p + 0; differences in toddlers of 0·3 pp [-1·0 to 1·6] for 1p + 1 vs 2p + 1 and -0·1 pp [-1·6 to 1·4] for 1p + 1 vs 3p + 0). The 0p + 1 schedule met non-inferiority in seven of eight intention-to-treat comparisons. The proportion of pneumococcal carriers carrying PCV10-type serotypes declined in infants (from 52·1% [160/307] to 7·6% [12/157]), toddlers (from 50·0% [246/492] to 4·0% [15/378]), and adult caregivers (from 39·4% [28/71]) to 10·5% [12/114]), at similar rates across age groups. During the trial period, 50 serious adverse events were reported within 1 month after vaccination, none of these events was deemed related to PCV10 vaccination. All children recovered without sequelae. INTERPRETATION: The 1p + 1 schedule remained non-inferior to standard three-dose schedules after 5·5 years. Across all intervention groups, VT carriage proportion declined at comparable rates in vaccinated children and unvaccinated adult caregivers, demonstrating that reduced-dose schedules can generate population-level indirect protection similar to standard schedules. These findings are most applicable to settings with established pneumococcal conjugate vaccine programmes following a catch-up campaign, and support 1p + 1 as a viable strategy for maintaining pneumococcal disease control while reducing programmatic costs and delivery complexity. FUNDING: Gates Foundation. TRANSLATIONS: For the Vietnamese translations of the abstract see Supplementary Material section.
2. Upsurge of pneumococcal clade I-α/CC180 serotype 3 and its association with a LytA mutation linked to immune evasion and disease potential: an observational and experimental study.
Serotype 3 clade I-α/CC180 has become dominant in Spain and exhibits enhanced resistance to complement/phagocytosis and increased lung cell infectivity. A lineage-wide LytA H166Y substitution increased autolysin activity and mechanistically accounted for phagocytosis evasion in CC180, coinciding with clonal replacement of vaccine-susceptible CC260 post-PCV13.
Impact: By linking a specific LytA mutation to immune evasion and clonal replacement, this study explains persistent serotype 3 disease despite PCV13 and highlights targets for next-generation vaccine and therapeutic strategies.
Clinical Implications: Enhanced surveillance for serotype 3 CC180 and consideration of vaccine formulations/strategies that better address this clade are warranted; LytA-related mechanisms may inform adjunctive therapies.
Key Findings
- Clade I-α/CC180 became predominant in Spain and shows increased resistance to complement-mediated immunity and phagocytosis, with greater lung epithelial infectivity.
- A lineage-wide LytA H166Y substitution increased enzymatic activity and mechanistically contributed to phagocytosis evasion in CC180 compared to CC260.
- Post-PCV13, vaccine-susceptible CC260 declined and was replaced by CC180; CC180 IPD was significantly associated with cardiac and respiratory comorbidities (p<0.05).
Methodological Strengths
- Integrated epidemiology, whole-genome sequencing, in vitro opsonophagocytosis, and in vivo pneumonia models.
- Clonal comparisons across vaccine eras with statistical modeling of incidence and genotype shifts.
Limitations
- Observational epidemiology limits causal inference regarding vaccine pressure and clonal shifts.
- Findings are country-specific; external validation across regions with differing vaccine use would strengthen generalizability.
Future Directions: Assess fitness/virulence of CC180 across settings, evaluate LytA-targeted interventions, and inform polyvalent/protein-based vaccine designs addressing serotype 3 escape.
BACKGROUND: Streptococcus pneumoniae serotype 3 is one of the most prevalent serotypes that cause invasive pneumococcal disease (IPD) in children and adults worldwide. Serotype 3 is associated with vaccine failures and breakthrough episodes in children vaccinated with 13-valent pneumococcal conjugate vaccine (PCV13). In this study, we aimed to investigate potential genetic mechanisms that could explain the increase in cases of serotype 3 IPD in Spain. METHODS: We analysed the epidemiology of serotype 3 causing IPD in Spain, during 2009-23, in different age groups. Molecular characterisation was performed by whole-genome sequencing. Host-pathogen interactions of the different lineages were evaluated in terms of interaction with lung epithelial cells, biofilm formation, and capsular polysaccharide production, using opsonophagocytosis assays and mouse models of pneumonia. We used Poisson regression models to compare incidence and chi-square test calculations to identify clonal variations across vaccine periods. FINDINGS: Genomic analyses confirmed the predominance of clade I-α/clonal complex (CC) 180 in Spain, which shows increased resistance to complement-mediated immunity and phagocytosis and enhanced potential to infect lung cells. In all isolates of this lineage, we observed a single amino acid substitution (166His→Tyr) in the crucial virulence factor LytA, which increased its enzymatic activity. On evaluating the phagocytosis of mutants without LytA of the two major lineages of serotype 3 (CC180 and CC260), LytA was responsible for the increased phagocytosis-evasion pattern of clade I-α/CC180. Evaluation of individuals with IPD caused by different serotype 3 genotypes confirmed a significant (p<0·05) association between cardiac and respiratory comorbidities and infection by sequence type 180/CC180, which showed the importance of CC180 in IPD. INTERPRETATION: Our findings confirm that PCV13 reduced IPD cases caused by the susceptible CC260 lineage until CC260 was replaced by the clade I-α/CC180 lineage, which has a higher potential to cause IPD and divert the host immune system. A key mutation on LytA protein was associated with this hypervirulent phenotype. Emerging lineages jeopardise the effectiveness of pneumococcal conjugate vaccines. FUNDING: Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, and PubMLST.
3. e-Lung computed tomography biomarkers are associated with outcomes in fibrotic interstitial lung diseases.
Across test (n=302) and validation (n=378) cohorts of non-IPF ILD, baseline e‑Lung WRVS independently predicted mortality (HR 1.11–1.12 per unit) and FVC decline/death after adjustment. A WRVS ≥15% identified high-risk patients (HR 4.77 and 3.49), and a serial WRVS rise of 3% was associated with significantly increased mortality risk.
Impact: Validates a fully automated CT biomarker that generalizes beyond IPF to non-IPF ILDs with actionable thresholds, enabling objective risk stratification and potentially guiding therapy escalation and trial enrichment.
Clinical Implications: WRVS can complement FVC and demographics to identify high-risk ILD patients (e.g., WRVS ≥15% or ≥3% rise) who may benefit from closer monitoring, earlier antifibrotic therapy, or trial enrollment.
Key Findings
- Baseline WRVS was associated with mortality in both cohorts (HR 1.11–1.12 per unit; p<0.001) with C-index up to 0.75.
- WRVS ≥15% strongly associated with mortality (test HR 4.77; validation HR 3.49).
- After adjustment for FVC, age, sex, WRVS predicted future FVC decline or death; a 3% serial increase in WRVS was linked to higher mortality (HR 5.69; 1.99).
Methodological Strengths
- Independent validation across two large cohorts (OSIC and a prospective national registry).
- Objective, automated CT feature extraction with prespecified thresholds and time-updated analyses.
Limitations
- Observational design limits causal inference; potential confounding by indication for serial CTs.
- External validation beyond European/OSIC datasets and across scanner/protocol variations is warranted.
Future Directions: Prospective interventional trials using WRVS for risk-adapted management; harmonization across vendors and integration into clinical workflows/decision tools.
BACKGROUND: The e-Lung weighted reticulovascular score (WRVS) is an automated computed tomography biomarker that quantifies interstitial lung disease (ILD) severity and is associated with prognosis in patients with idiopathic pulmonary fibrosis (IPF). The aims of the present study were to evaluate WRVS as a prognostic factor in patients with non-IPF ILD. METHODS: The test cohort comprised patients from the Open Source Imaging Consortium and the validation cohort, patients recruited to the prospective German CoWorker ILD registry. Associations between baseline and serial WRVS with future forced vital capacity (FVC) decline and survival were tested. RESULTS: Median survival was 7.1 and 6.1 years in the test (n=302) and validation (n=378) cohorts, respectively. Baseline WRVS was associated with mortality in test (hazard ratio (HR) 1.11, 95% CI 1.08-1.14; p<0.001, C-index 0.75) and validation (HR 1.12, 95% CI 1.09-1.15; p<0.001, C-index 0.72) cohorts. A threshold WRVS of ≥15% was associated with mortality in both cohorts (HR 4.77, 95% CI 3.11-7.31; p<0.001, C-index 0.71, and HR 3.49, 95% CI 2.48-4.91; p<0.001, C-index 0.63 for test and validation cohorts, respectively). After adjustment for FVC, age and sex, baseline WRVS was associated with future FVC decline or death in test (OR 1.13, 95% CI 1.06-1.21; p<0.001, C-index 0.72) and validation (OR 1.18, 95% CI 1.11-1.25; p<0.001, C-index 0.72) cohorts. A rise in WRVS of 3% on serial computed tomography was associated with mortality in both test (HR 5.69, 95% CI 2.77-11.70; p<0.001, C-index 0.75) and validation cohorts (HR 1.99, 95% CI 1.09-3.65; p=0.026, C-index 0.57). CONCLUSION: In patients with non-IPF ILD, the e-Lung WRVS biomarker is associated with mortality and FVC decline when applied to baseline high-resolution computed tomography scans replicating previous studies in IPF. Patients with an increase in WRVS of 3% on serial computed tomography scans have significantly increased risk of mortality.