High Flow Nasal Cannula Versus Noninvasive Positive Pressure Ventilation as Initial Respiratory Support in Patients with Chronic Obstructive Pulmonary Disease and Covid-19: Exploratory Analysis in Two Intensive Care Units.

OBJECTIVE: To identify the type of the non-invasive ventilatory treatment for patients diagnosed with chronic obstructive pulmonary disease (COPD), with respiratory status deteriorated by COVID-19 pneumonia, and in need of treatment in the Intensive Care Unit (ICU). MATERIALS AND METHODS: This cross-sectional study was conducted over a one-year period in the medical intensive care units of two hospitals. As the patients' clinical condition deteriorated and the parameters of the arterial blood gas (ABG) analysis worsened, oxygen support was applied via a high flow nasal cannula (HFNC) or by non-invasive positive pressure ventilation (NPPV). According to the control values of the arterial oxygen saturation (SaO2) and the parameters of ABG, the patients were enabled to be transferred between the two types of non-invasive ventilatory support. The primary outcome was the length of hospital stay, while secondary outcomes were the rate of intubation, the mortality rate, and respiratory supportfree days. RESULTS: Out of 21 critical patients with COPD and COVID-19, 11 (52.4%) were initially treated with NPPV and 10 (47.6%) with HFNC. The ages (67±9.79 in NPPV group vs. 70.10±10.25 in HFNC group) and severity of illness (SOFA score 5 (3.5) in NPPV group vs. 5 (2.8) in HFNC group) were similar between the two groups. Switching the mode of respiratory support was more common in NPPV (58.3% in survivor group vs. 41.7% in non-survivor group). Patients treated with NPPV compared to HFNC had a nominally longer length of stay (15 (11) vs. 11.5 (4.25)), and higher risk of intubation (66.7% vs. 33.3%) and mortality (66.7% vs. 33.3%), but the comparisons did not reach statistical significance. Survivors had significantly longer Medical Intensive Care Unit and hospital stays, but significantly lower FiO2 (0.60 vs.1) and higher values of PaO2/FiO2 (78(32.4) vs. 56.3(17.8)) than non-survivors. All patients were treated with corticosteroids, and the duration of treatment was similar between groups. CONCLUSION: In critically ill patients with COPD and COVID-19, both HFNC and NPPV were commonly used as the initial mode of ventilation. Switching to a different mode and adverse patient outcomes were more frequent in patients initially treated with NPPV. Survivors had higher values of PaO2/FiO2 than non-survivors.

Comparison of IgA, IgG, and Neutralizing Antibody Responses Following Immunization With Moderna, BioNTech, AstraZeneca, Sputnik-V, Johnson and Johnson, and Sinopharm's COVID-19 Vaccines.

In an ongoing multinational trial, we obtained blood samples from 365 volunteers vaccinated with mRNA vaccines (Moderna, BioNTech), viral DNA-vectored vaccines (AstraZeneca, Sputnik-V, and Johnson and Johnson), or the attenuated virus vaccine from Sinopharm. After collecting reactogenicity data, the expression of S-Protein binding IgG and IgA was analyzed using an automated sandwich ELISA system. Serum neutralizing potentials were then investigated using an ACE-2-RBD neutralizing assay. Moderna's vaccine induced the highest amounts of SARS-CoV-2 specific neutralizing antibodies compared to the other groups. In contrast, Sinopharm and Johnson and Johnson's vaccinees presented the lowest SARS-CoV-2-specific antibody titers. Interestingly, moderate to high negative correlations between age and virus-specific IgG expression were observed in the Johnson and Johnson (ρ =-0.3936) and Sinopharm (ρ =-0.6977) groups according to Spearman's rank correlation analysis. A negative correlation was seen between age and IgA expression in the Sputnik-V group (ρ =-0.3917). The analysis of virus neutralization potentials in age categories demonstrated that no significant neutralization potential was observed in older vaccinees (61and 80 years old) in the Sputnik-V Johnson and Johnson and Sinopharm vaccinees' groups. In contrast, neutralization potentials in sera of Moderna, BioNTech, and AstraZeneca vaccinees were statistically comparable in all age categories. Furthermore, while the AstraZeneca vaccine alone induced moderate IgG and IgA expression, the combination with Moderna or BioNTech mRNA vaccines induced significantly higher antibody levels than a double dose of AstraZeneca and similar IgG expression and neutralization potential compared to Moderna or BioNTech vaccines used alone. These results suggest that mRNA vaccines are the most immunogenic after two doses. DNA vectored vaccines from AstraZeneca and Sputnik-V presented lower but significant antibody expression and virus neutralizing properties after two doses. The lowest antibody and neutralization potential were observed in the Sinopharm or Johnson and Johnson vaccinees. Especially elderly over 60 presented no significant increase in neutralizing antibodies after vaccination. The data also indicate that heterologous vaccination strategies combining the AstraZeneca DNA vectored vaccines and mRNA vaccines are more effective in the induction of neutralizing antibodies compared to their homologous counterparts.