Decline of Anti-SARS-CoV-2 IgG Antibody Levels 6 Months after Complete BNT162b2 Vaccination in Healthcare Workers to Levels Observed Following the First Vaccine Dose.

Research on post-vaccination antibody dynamics has become pivotal in estimating COVID-19 vaccine efficacy. We studied anti-SARS-CoV-2 Spike RBD IgG levels in 587 healthcare workers (2038 sera) who completed BNT162b2 vaccination. Average antibody titer 3 weeks after the first dose in COVID-19-naïve participants (median 873.5 AU/mL) was 18-fold higher than the test threshold, with a significant increase 1 month (median 9927.2 AU/mL) and an exponential decrease 3 (median 2976.7 AU/mL) and 6 (median 966.0 AU/mL) months after complete vaccination. Participants with a history of COVID-19 prior to vaccination showed significantly higher antibody levels, particularly after the first dose (median 14,280.2 AU/mL), with a slight decline 1 month (median 12,700.0 AU/mL) and an exponential decline in antibody titers 3 (median 4831.0 AU/mL) and 6 (median 1465.2 AU/mL) months after vaccination. Antibody levels of COVID-19-naïve subjects after the first dose were moderately correlated with age (r = -0.4). Multivariate analysis showed a strong independent correlation between IgG levels 6 months after vaccination and both IgG titers after the first dose and 1 month after vaccination (R2 = 0.709). Regardless of pre-vaccination COVID-19 history, IgG levels 6 months after vaccination were comparable to antibody levels reached by COVID-19-naïve participants after the first vaccine dose.

Nosocomial blood stream infections in patients treated with venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome.

BACKGROUND: The incidence of complication rates in patients treated with venovenous extracorporeal membrane oxygenation (VV ECMO) remains substantial and impacts the results of any future trial dealing with ECMO efficacy. Of these complications blood stream infections (BSI) are less well studied. Our objective was to report influence of BSI in ARDS patients treated with VV ECMO. METHODS: One-hundred adult patients with ARDS treated with VV ECMO at the tertiary care hospital in Zagreb, Croatia between the October of 2009 and the June of 2016 were prospectively included in the study. RESULTS: In 35% of patients an episode of the nosocomial BSI during VV ECMO treatment was detected. ECMO duration of more than 250 hours and significant bleeding episode independently increase the possibility of acquiring BSI during an ECMO run (odds ratio 3.189, 95% confidence limits 1.108-9.180 and odds ratio 3.378, 95% confidence limits 1.055-10.869 respectively). BSI occurrence had no effect on mortality. CONCLUSIONS: Our study found that BSI incidence increases with the duration of an ECMO run and bleeding complications with no effect on hospital mortality. Further studies of BSI in this risk group should address the problem of rapid diagnosis and appropriate antimicrobial therapy in an era of growing multiresistance.

Venovenous extracorporeal membrane oxygenation for ARDS: outcome analysis of a Croatian referral center for respiratory ECMO.

BACKGROUND: The use of venovenous extracorporeal membrane oxygenation (VV-ECMO) as a rescue therapy in severe acute respiratory distress syndrome (ARDS) has become well established; however, the affirmation of evidence on VV-ECMO application and the analysis of patient outcomes after VV-ECMO treatment for ARDS continues. The aim of the study is to identify variables that affected the outcome of patients treated with VV-ECMO for severe ARDS outside a major ECMO center. METHODS: The study included adult patients with severe ARDS treated with ECMO at a tertiary care hospital in Zagreb, Croatia between October 2009 and July 2014. Patients were recruited from a prospective database. RESULTS: The study enrolled 40 patients, 20 of whom had H1N1-induced ARDS. The hospital mortality was 38%. The difference in mortality and long-term outcome in H1N1-induced ARDS as compared to non-H1N1-induced ARDS was not significant. Variables associated with mortality included immunosuppression, shock at time of admission, acute renal failure, occurrence of heparin-induced thrombocytopenia antibodies, nosocomial sepsis and duration of ECMO. CONCLUSIONS: The results of our study indicate that ECMO use in severe ARDS is feasible with low mortality and identify or assert the variables associated with adverse outcomes.

Extracorporeal membrane oxygenation treatment for H1N1-induced acute respiratory distress syndrome (ARDS): results of the Croatian Referral Center for Respiratory ECMO.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) has been effective in the treatment of H1N1-induced ARDS across the globe. However, the evidence supporting the use of ECMO in ARDS is still being collected. The intention of this study was to add a piece of puzzle to the growing body of evidence on the use of ECMO in ARDS patients. METHODS: The study included adult patients with H1N1-induced ARDS treated with ECMO at the University Hospital for Infectious Diseases in Zagreb, Croatia between October 2009 and December 2013. RESULTS: 17 patients with H1N1-induced ARDS treated with ECMO were included in the study. The patient cohort of the study was young with a median age of 43 years (range 23-74). The hospital mortality was 35%. Possible variables associated with mortality were analyzed and only hemolysis was found to be significant. CONCLUSIONS: Our results confirm the usefulness of ECMO treatment in patients with H1N1-induced ARDS.