Cytokine fingerprint differences following infection and vaccination - what can we learn from COVID-19?

COVID-19 vaccination and acute infection result in cellular and humoral immune responses with various degrees of protection. While most studies have addressed the difference in humoral response between vaccination and acute infection, studies on the cellular response are scarce. We aimed to evaluate differences in immune response among vaccinated patients versus those who had recovered from COVID-19. This was a prospective study in a tertiary medical centre. The vaccinated group included health care workers, who had received a second dose of the BNT162b2 vaccine 30 days ago. The recovered group included adults who had recovered from severe COVID-19 infection (<94% saturation in room air) after 3-6 weeks. Serum anti-spike IgG and cytokine levels were taken at entry to the study. Multivariate linear regression models were applied to assess differences in cytokines, controlling for age, sex, BMI, and smoking status. In total, 39 participants were included in each group. The mean age was 53 ±14 years, and 53% of participants were males. Baseline characteristics were similar between the groups. Based on multivariate analysis, serum levels of IL-6 (ß=-0.4, p<0.01), TNFα (ß=-0.3, p=0.03), IL-8 (ß=-0.3, p=0.01), VCAM-1 (ß=-0.2, p<0.144), and MMP-7 (ß=-0.6, p<0.01) were lower in the vaccinated group compared to the recovered group. Conversely, serum anti-spike IgG levels were lower among the recovered group (124 vs. 208 pg/mL, p<0.001). No correlation was identified between antibody level and any of the cytokines mentioned above. Recovered COVID-19 patients had higher cytokine levels but lower antibody levels compared to vaccinated participants. Given the differences, these cytokines might be of value for future research in this field.

Assessment of a close respiratory follow-up schedule at 3 and 6 months after acute COVID-19 and its related investigations.

BACKGROUND: Respiratory sequela after acute COVID-19 is common and requires medical follow-up. Considering its vast economic impact, there is still no consensus regarding the mid-term follow-up plan after recovery. OBJECTIVE: To evaluate the necessity of a close pulmonary follow-up schedule after acute COVID-19 and its related investigations. METHODS: A prospective cohort study including adult patients after acute COVID-19 pneumonia. Patients were invited or referred to a 3- and 6-month follow-up visits at a large pulmonary institute in a tertiary center. Before each visit, patients completed demographic and clinical questionnaires, pulmonary function tests (PFTs), and chest CT scans. RESULTS: 168 patients were included after completing both visits (medians of 80 and 177 days). Their mean age was 58 ± 15 and 52% recovered from severe or critical COVID-19. Between the two visits, there was no change in DLCOc (mean 73 ± 18 %predicted in both visits) and FVC (mean 90 ± 16 vs. 89 ± 16 %predicted). The COPD assessment tool and modified Medical Research Council scale had inverse correlations with the DLCOc, and similarly did not change between the visits. Occupational exposures were the only factor associated with a change in DLCOc during follow-up (3% decrease, p = 0.04). An improvement in chest CT findings at the second visit was not associated with a change in PFTs. CONCLUSIONS: Most clinical variables did not change during a close follow-up schedule in the first six months after acute COVID-19. Such a follow-up plan does not appear necessary and should be personalized to limit excessive costs and resources.

Interactions and clinical implications of serological and respiratory variables 3 months after acute COVID-19.

Medical follow-up of symptomatic patients after acute Coronavirus Disease 2019 (COVID-19) results in major burdens on patients and healthcare systems. The value of serological markers as part of this follow-up remains undetermined. We aimed to evaluate the clinical implications of serological markers for follow-up of acute COVID-19. For this purpose, we conducted an observational cohort study of patients 3 months after acute COVID-19. Participants visited a respiratory-clinic between October 2020 and March 2021, and completed pulmonary function tests (PFTs), serological tests, symptom-related questionnaires, and chest CT scans. Overall, 275 patients were included at a median of 82 days (IQR 64-111) post infection. 162 (59%) patients had diffusing capacity for carbon monoxide corrected for hemoglobin (DLCOc) below 80%, and 69 (25%) had bilateral chest abnormalities on CT scan. In multivariate analysis, anti-S levels were an independent predictor for DLCOc (ß = - 0.14, p = 0.036). Anti-S levels were also associated with severe COVID-19 and older age, and correlated with anti-nucleocapsid (r = 0.30, p < 0.001) and antibodies to receptor binding domain (RBD, r = 0.37, p < 0.001). Other serological variables were not associated with clinical outcomes. In conclusion, symptomatic patients 3-months after COVID-19 had high respiratory symptomatic burden, in which anti-S levels were significantly associated with previous severe COVID-19 and DLCOc.

Blood Stream Infections in Burns: A 14-Year Cohort Analysis.

BACKGROUND: Blood stream infections are a significant cause of morbidity and mortality in burns, and pathogen identification is important for treatment. This study aims to characterize the microbiology of these infections and the association between the infecting pathogen and the hospitalization course. METHODS: We conducted a cohort study that included records of burn patients treated at the Soroka University Medical Center between 2007-2020. Statistical analysis of demographic and clinical data was performed to explore relationships between burn characteristics and outcomes. Patients with positive blood cultures were divided into four groups: Gram-positive, Gram-negative, mixed-bacterial, and fungal. RESULTS: Of the 2029 burn patients hospitalized, 11.7% had positive blood cultures. The most common pathogens were Candida and Pseudomonas. We found significant differences in ICU admission, need for surgery, and mortality between the infected and non-infected groups (p < 0.001). Pathogen groups differed significantly mean TBSA, ICU admission, need for surgery, and mortality (p < 0.001). Multivariate analysis showed flame (OR 2.84) and electric burns (OR 4.58) were independent risk factors for ICU admission and surgical intervention (p < 0.001). Gram-negative bacterial infection was found to be an independent predictor of mortality (OR = 9.29, p < 0.001). CONCLUSIONS: Anticipating specific pathogens which are associated with certain burn characteristics may help guide future therapy.