SARS-CoV-2 mRNA vaccination induces robust humoral and cellular immunity in the circulation; however, it is currently unknown whether it elicits effective immune responses in the respiratory tract, particularly against variants of concern (VOCs), including Omicron. We compared the SARS-CoV-2 S–specific total and neutralizing antibody responses, and B and T cell immunity, in the bronchoalveolar lavage fluid (BAL) and blood of COVID-19–vaccinated individuals and hospitalized patients. Vaccinated individuals had significantly lower levels of neutralizing antibody against D614G, Delta (B.1.617.2), and Omicron BA.1.1 in the BAL compared with COVID-19 convalescents despite robust S-specific antibody responses in the blood. Furthermore, mRNA vaccination induced circulating S-specific B and T cell immunity, but in contrast to COVID-19 convalescents, these responses were absent in the BAL of vaccinated individuals. Using a mouse immunization model, we demonstrated that systemic mRNA vaccination alone induced weak respiratory mucosal neutralizing antibody responses, especially against SARS-CoV-2 Omicron BA.1.1 in mice; however, a combination of systemic mRNA vaccination plus mucosal adenovirus-S immunization induced strong neutralizing antibody responses not only against the ancestral virus but also the Omicron BA.1.1 variant. Together, our study supports the contention that the current COVID-19 vaccines are highly effective against severe disease development, likely through recruiting circulating B and T cell responses during reinfection, but offer limited protection against breakthrough infection, especially by the Omicron sublineage. Hence, mucosal booster vaccination is needed to establish robust sterilizing immunity in the respiratory tract against SARS-CoV-2, including infection by the Omicron sublineage and future VOCs.

No abstract

Abbreviations: ACR 5 American College of Rheumatology; CHF 5 congestive heart failure; CKD 5 chronic kidney disease; ILD 5 interstitial lung disease; IQR 5 interquartile range; PAH 5 pulmonary arterial hypertension; REP 5 Rochester Epidemiology Project; SSc 5 systemic sclerosis

Pleural effusion size, amount of pleural fluid drained, LDH and pleural fluid cytology were found to be risk factors for recurrence.

A bronchopleural fistula (BPF) is a communication between the pleural space and the bronchial tree. BPFs are challenging to diagnose and are associated with a high morbidity and mortality. Sequential balloon occlusion is commonly used for localization of a BPF. We describe our experience with 4 cases of successful localization of the BPF by instillation of methylene blue into the pleural space through a pigtail catheter, with simultaneous bronchoscopic visualization of dye in the tracheobronchial tree. Two patients were treated with endobronchial valves and 3 had a surgical thoracic muscle flap placed.

Lung cell injury and repair is a hallmark of the acute respiratory distress syndrome (ARDS). Lung protective mechanical ventilation strategies in these patients may lead to hypercapnia (HC). Although HC has been explored in the clinical context of ARDS, its effect upon alveolar epithelial cell (AEC) wounding and repair remains poorly understood. We have previously reported that HC alters the likelihood of AEC repair by a pH-sensitive but otherwise unknown mechanism. Adenylate cyclase (AC) is an attractive candidate as a putative AEC CO2 sensor and effector as it is bicarbonate sensitive and controls key mediators of AEC repair. The effect of HC on AC activity and plasma membrane (PM) wound repair was measured in AEC type 1 exposed to normocapnia (NC, 40 Torr) or HC (80 Torr), ± tromethamine (THAM) or sodium bicarbonate (HCO3) ± AC probes in a micropuncture model of AEC injury relevant to ARDS. Intracellular pH and AC activity were measured and correlated with repair. HC decreased intracellular pH 0.56, cAMP by 37%, and absolute PM repair rate by 26%. Buffering or pharmacologic manipulation of AC reduced or reversed the effects of HC on AC activity (THAM 103%, HCO3 113% of NC cAMP, ns; Forskolin 168%, p < 0.05) and PM repair (THAM 87%, HCO3 108% of NC likelihood to repair, ns; Forskolin 160%, p < 0.01). These findings suggest AC to be a putative AEC CO2 sensor and modulator of AEC repair, and may have implications for future pharmacologic targeting of downstream messengers of the AC-cAMP axis in experimental models of ARDS.

A 51-year-old man presented with progressively worsening lung infiltrates and respiratory failure. Extensive investigations including bronchoscopy with bronchoalveolar lavage and conventional transbronchial forceps biopsies failed to establish the diagnosis. After transfer to our institution, he underwent repeat bronchoscopy with transbronchial cryobiopsy, which provided large, high-quality biopsy specimens establishing the diagnosis of parenchymal diffuse large B-cell lymphoma.

No abstract