Daily Respiratory Research Analysis
Three impactful studies advance respiratory science and practice: a Cell Reports mechanistic study shows SARS-CoV-2 nsp1 broadly blocks mammalian translation with a bat 40S ribosome cryo-EM structure; a population-scale analysis from California demonstrates 2023–2024 influenza vaccine effectiveness using linked public health systems data; and a 15-year cohort in Chest shows PRISm increases risk of future airflow limitation even in never-smokers, with higher risk in ever-smokers.
Summary
Three impactful studies advance respiratory science and practice: a Cell Reports mechanistic study shows SARS-CoV-2 nsp1 broadly blocks mammalian translation with a bat 40S ribosome cryo-EM structure; a population-scale analysis from California demonstrates 2023–2024 influenza vaccine effectiveness using linked public health systems data; and a 15-year cohort in Chest shows PRISm increases risk of future airflow limitation even in never-smokers, with higher risk in ever-smokers.
Research Themes
- Cross-species viral–host interaction mechanisms in respiratory pathogens
- Real-world vaccine effectiveness using linked public health surveillance
- Early COPD precursors (PRISm) and trajectories toward airflow limitation
Selected Articles
1. SARS-CoV-2 nsp1 mediates broad inhibition of translation in mammals.
Using bat and other mammalian cells, the authors demonstrate that SARS-CoV-2 nsp1 broadly blocks translation across species. Cryo-EM reveals nsp1 occludes the mRNA entry channel on the Rhinolophus lepidus 40S ribosome at a conserved site, explaining cross-species activity and informing spillover biology.
Impact: This rigorous mechanistic study reveals a conserved structural basis for host shutoff across mammals, advancing understanding of SARS-CoV-2 host range and immune evasion.
Clinical Implications: While preclinical, targeting the nsp1–ribosome interface could inform antiviral design and risk assessment for cross-species maintenance and spillover events.
Key Findings
- nsp1 strongly inhibits protein translation in Rhinolophus lepidus bat cells.
- Cryo-EM structure shows nsp1 blocks the 40S ribosomal mRNA entry channel at a conserved mammalian site.
- nsp1 inhibits translation across multiple mammalian species, indicating a conserved mechanism of host shutoff.
Methodological Strengths
- High-resolution cryo-EM structural determination of nsp1–ribosome complex
- Cross-species cellular validation demonstrating conserved functional effect
Limitations
- Findings are based on in vitro cellular systems without in vivo disease models
- No direct therapeutic intervention or animal outcome data presented
Future Directions: Elucidate nsp1 dynamics during infection in vivo, assess species-specific modifiers of ribosomal binding, and explore small molecules that disrupt the nsp1–40S interface.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) non-structural protein 1 (nsp1) promotes innate immune evasion by inhibiting host translation in human cells. However, the role of nsp1 in other host species remains elusive, especially in bats-natural reservoirs of sarbecoviruses with a markedly different innate immune system than humans. We reveal that nsp1 potently inhibits translation in Rhinolophus lepidus bat cells, which belong to the same genus as known sarbecovirus reservoir hosts. We determined a cryoelectron microscopy structure of nsp1 bound to the R. lepidus 40S ribosomal subunit, showing that it blocks the mRNA entry channel by targeting a highly conserved site among mammals. Accordingly, we found that nsp1 blocked protein translation in mammalian cells from several species, underscoring its broadly inhibitory activity and conserved role in numerous SARS-CoV-2 hosts. Our findings illuminate the arms race between coronaviruses and mammalian host immunity, providing a foundation for understanding the determinants of viral maintenance in bat hosts and spillover.
2. Lung Function Decline and Airflow Limitation Risk in Preserved Ratio Impaired Spirometry Subtypes by Smoking Status.
In a 15-year population-based cohort of 2,850 adults, both non-smoking PRISm and ever-smoking PRISm increased the risk of developing airflow limitation versus normal spirometry, with the highest risk in ever-smokers (adjusted HR 2.69 vs normal). Ever-smoking PRISm also showed faster lung function decline than non-smoking PRISm.
Impact: Clarifies PRISm as a clinically relevant precursor state for COPD even in never-smokers and quantifies progression risk by smoking status.
Clinical Implications: PRISm warrants longitudinal surveillance and risk modification (e.g., smoking cessation, comorbidity management) regardless of smoking history; may inform screening thresholds and early interventions.
Key Findings
- Ever-smoking PRISm had a markedly higher risk of incident airflow limitation vs normal spirometry (adjusted HR 2.69) and vs non-smoking PRISm (adjusted HR 1.90).
- Non-smoking PRISm also increased airflow limitation risk vs normal spirometry (adjusted HR 1.41).
- Annual lung function decline was fastest in normal controls, followed by ever-smoking PRISm, and slowest in non-smoking PRISm; however, risk of progression was highest in ever-smoking PRISm.
Methodological Strengths
- Population-based, 15-year prospective cohort with clear subgrouping by smoking status
- Time-to-event modeling with adjusted hazard ratios and subgroup analyses
Limitations
- Generalizability may be limited to the cohort population and definitions of PRISm
- Potential residual confounding and measurement variability in spirometry over long follow-up
Future Directions: Evaluate targeted interventions in PRISm (including non-smokers), define imaging and biomarker correlates, and refine risk stratification tools for progression.
BACKGROUND: Preserved ratio impaired spirometry (PRISm) is regarded as a COPD precursor, but whether this varies by smoking status remains unclear. RESEARCH QUESTION: Are annual lung function decline and the risk of developing airflow limitation different among PRISm subtypes by smoking status? STUDY DESIGN AND METHODS: A total of 2,850 participants from a 15-year population-based prospective cohort were included in this analysis. Participants were categorized into 3 groups: patients with normal spirometry who do not smoke (normal control), patients with PRISm who do not smoke (NS-PRISm), and patients with PRISm who have ever smoked (ES-PRISm). We compared annual lung function decline and the risk of developing airflow limitation among the 3 groups. RESULTS: Participants in the normal control group exhibited the fastest decline in annual lung function, followed by the ES-PRISm group, with the NS-PRISm group showing the slowest decline. Participants in the ES-PRISm group had significantly faster annual lung function decline than the NS-PRISm group. Participants in the ES-PRISm group had a significantly increased risk of developing airflow limitation than the NS-PRISm group (95 of 256 [37.1%] vs 69 of 470 [14.7%]; adjusted hazard ratio [HR], 1.90; 95% CI, 1.31-2.77; P = .001) and normal control group (95 of 256 [37.1%] vs 193 of 2,124 [9.1%]; adjusted HR, 2.69; 95% CI, 1.96-3.69; P < .001). Participants in the NS-PRISm group also exhibited a higher risk of developing airflow limitation than those in the normal control group (69 of 470 [14.7%] vs 193 of 2,124 [9.1%]; adjusted HR, 1.41; 95% CI, 1.07-1.87; P = .016). When the ES-PRISm group was further divided into participants with PRISm who currently smoke and those who formerly smoked, both of these PRISm subtypes showed a faster annual lung function decline and a similarly higher risk of airflow limitation than the NS-PRISm group. INTERPRETATION: These findings suggest that both NS-PRISm and ES-PRISm may be potential precursors to COPD and indicate that PRISm should not be restricted to evaluating individuals with a history of smoking alone.
3. Estimating Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza Using Linked Public Health Information Systems, California, 2023-2024 Season.
Linking statewide immunization registry and lab reports for 1.38 million tests in 2023–2024, the study estimated influenza VE of 41% overall, 32% against A, 68% against B, and 26% in adults ≥65 years. The work demonstrates scalable, near-real-time VE assessment using routine public health systems.
Impact: Provides policy-relevant VE estimates at population scale and validates a sustainable surveillance-based approach for annual vaccine performance monitoring.
Clinical Implications: Supports continued influenza vaccination, highlights lower VE in older adults, and enables health departments to rapidly assess VE for strain and program adjustments.
Key Findings
- Overall VE against lab-confirmed influenza was 41% (95% CI 40–42%) using linked registry–lab data.
- Subtype-specific VE: 32% for influenza A and 68% for influenza B.
- VE among adults ≥65 years was 26%, indicating reduced protection in older adults.
Methodological Strengths
- Very large sample with individual-level linkage between immunization registry and lab results
- Adjusted logistic regression accounting for demographics, time, and geography
Limitations
- Potential residual confounding and differential healthcare-seeking behavior
- Vaccination status may be misclassified if administered outside captured systems
Future Directions: Integrate severity outcomes (hospitalization, mortality), assess VE by risk groups and prior infection status, and enable in-season VE updates to inform campaigns.
BACKGROUND: Mandatory public health reporting of influenza laboratory results and vaccine doses administered in the state of California can provide estimates of seasonal influenza vaccine effectiveness (VE). METHODS: We analyzed linked influenza immunization registry and laboratory reporting data among California residents aged ≥6 months tested for influenza during the 2023-2024 influenza season (October 2023 to June 2024). Individually linked laboratory reporting included influenza molecular or viral culture test result. Odds ratios (OR) and 95% confidence intervals (CI) contrasted odds of documented 2023-2024 vaccination among persons with influenza-positive tests versus persons with negative influenza tests. VE was calculated as (1 - adjusted OR) × 100 using logistic regression, adjusting for patient age, race, ethnicity, week of specimen collection, and county of residence. RESULTS: Among 1 382 142 laboratory reports, 129 253 persons (9%) had a positive influenza test result, of whom 415 390 (30%) had documented influenza vaccination ≥ 14 days before test date. VE against laboratory-confirmed influenza was 41% (95% CI, 40%-42%). VE was 32% (95% CI, 31%-33%) against influenza A, 68% (95% CI, 66%-69%) against influenza B, and 26% (95% CI, 24%-29%) among adults aged ≥ 65 years. CONCLUSIONS: Influenza vaccination was associated with prevention of laboratory-confirmed influenza. Results demonstrated the feasibility of assessing seasonal influenza VE using linked immunization and laboratory data from public health surveillance systems.