Neto, A. C. | bioRxiv Science

bioRxiv2020

Zebrafish studies on the vaccine candidate to COVID-19, the Spike protein: Production of antibody and adverse reaction

Establishing new experimental animal models to assess the safety and immune response to the antigen used in the development of COVID-19 vaccine is an imperative issue. Based on the advantages of using zebrafish as a model in research, herein we suggest doing this to test the safety of the putative vaccine candidates and to study immune response against the virus. We produced a recombinant N-terminal fraction of the Spike SARS-CoV-2 protein and injected it into adult female zebrafish. The specimens generated humoral immunity and passed the antibodies to the eggs. However, they presented adverse reactions and inflammatory responses similar to severe cases of human COVID-19. The analysis of the structure and function of zebrafish and human Angiotensin-converting enzyme 2, the main human receptor for virus infection, presented remarkable sequence similarities. Moreover, bioinformatic analysis predicted protein-protein interaction of the Spike SARS-CoV-2 fragment and the Toll-like receptor pathway. It might help in the choice of future therapeutic pharmaceutical drugs to be studied. Based on the in vivo and in silico results presented here, we propose the zebrafish as a model for translational research into the safety of the vaccine and the immune response of the vertebrate organism to the SARS-CoV-2 virus.

immunology↗

bioRxiv2019

Impact of intensive care unit admission during handover on mortality: a propensity matched cohort study

IntroductionHandover is a process of transferring information, responsibility and authority for providing care of critically ill patients from a departing intensivist to an oncoming intensivist. The effect of i admission during a medical handover on clinical outcomes is unknown. ObjectivesOur purpose was to evaluate the impact of ICU admission during a medical handover on clinical outcomes. MethodsPost hoc analysis of a cohort study addressing the effect of ICU admissions during the handover on outcomes. This retrospective, single center, propensity matched cohort study was conducted in a 41-bed open general ICU located in a private tertiary care hospital in Sao Paulo, Brazil. Based on time of ICU admission, patients were categorized into two cohorts: handover group (ICU admission between 6:30 am to 7:30 or 6:30 pm to 7:30 pm) or control group (admission between 7:31 am to 6:29 pm or 7:31 pm to 6:29 am). Patients in the handover group were propensity matched to patients in the control group at 1:2 ratio. Our primary outcome was hospital mortality. ResultsBetween June 1, 2013 and May 31, 2015, 6,650 adult patients were admitted to the ICU. Following exclusion of ineligible participants, 5,779 patients [389 (6.7%) in handover group and 5390 (93.3%) in control group] were eligible for propensity score matching, of whom 1,166 were successfully matched [389 (33.4%) handover group and 777 (66.6%) in control group]. Before matching, hospital mortality was 14.1% (55/389 patients) in handover group compared to 11.7% (628/5,390) in control group (p=0.142). After propensity-score matching, ICU admission during handover was not associated with increased risk of ICU (OR, 1.40; 95% CI, 0.92 to 2.11; p=0.11) and hospital (OR, 1.23; 95%CI, 0.85 to 1.75; p=0.26) mortality. ICU and hospital length of stay did not differ between the groups. ConclusionIn this propensity-matched single center cohort study, ICU admission during medical handover did not affect clinical outcomes.

scientific communication and education↗