Clinical Efficacy of SARS-CoV-2 Vaccination in Hemodialysis Patients.

Introduction: The COVID-19 pandemic is a global public health problem. Patients with end-stage renal disease on hemodialysis are at a higher risk of infection and mortality than the general population. Worldwide, a vaccination campaign has been developed that has been shown to reduce severe infections and deaths in the general population. However, there are currently limited data on the clinical efficacy of vaccinations in the hemodialysis population. Methods: A national multicenter observational cohort was performed in Chile to evaluate the clinical efficacy of anti-SARS-CoV-2 vaccination in end-stage renal disease patients on chronic hemodialysis from February 2021 to August 2021. In addition, the BNT162b2 (Pfizer-BioNTech) and CoronaVac (Sinovac) vaccines were evaluated. The efficacy of vaccination in preventing SARS-CoV-2 infection, hospitalizations, and deaths associated with COVID-19 was determined. Results: A total of 12,301 patients were evaluated; 10,615 (86.3%) received a complete vaccination (2 doses), 490 (4.0%) received incomplete vaccination, and 1196 (9.7%) were not vaccinated. During follow-up, 1362 (11.0%) patients developed COVID-19, and 150 died (case fatality rate: 11.0%). The efficacy of the complete vaccination in preventing infection was 18.1% (95% confidence interval [CI]:11.8-23.8%), and prevention of death was 66.0% (95% CI:60.6-70.7%). When comparing both vaccines, BNT162b2 and CoronaVac were effective in reducing infection and deaths associated with COVID-19. Nevertheless, the BNT162b2 vaccine had higher efficacy in preventing infection (42.6% vs. 15.0%) and deaths (90.4% vs. 64.8%) compared to CoronaVac. Conclusion: The results of our study suggest that vaccination against SARS-CoV-2 in patients on chronic hemodialysis was effective in preventing infection and death associated with COVID-19.

Survival study and factors associated with mortality in Chilean patients on peritoneal dialysis infected with SARS-CoV-2.

The Covid-19 pandemic has been responsible for millions of deaths worldwide. Patients with comorbidities- such as those on peritoneal dialysis (PD)- present higher morbidity and mortality than the general population. We prospectively evaluated all Chilean patients on PD (48 centres) and followed those who had Covid-19 from the beginning of the Covid-19 pandemic in Chile (March 2020) to January 2021 (start of vaccination campaign). We described demographic history, comorbidities, factors related to infection, need for hospitalisation and death due to Covid-19. During the study period, 106 adults on PD were infected by SARS-CoV-2, with a mean age of 53.1 (±16.3) and of which 53.9% were female. From that group, 54.8% required hospitalisation and 24.5% (n = 26) died due to Covid-19. Most of the patients (63.4%) were infected at home and 22.8% during hospitalisation for other reasons. There was a significant association for Covid-19 mortality with: being ≥60 years old, diabetes, time on PD ≥5 years, need for hospitalisation and hospital-acquired infection. At 90 days of follow-up, all deaths associated to Covid-19 occurred before 40 days. We conclude that patients on PD without Covid-19 vaccination have a high mortality and need for hospitalisation associated to Covid-19. To avoid this negative outcome, it is necessary to intensify strategies to avoid contagion, especially in those ≥60 years old, with diabetes and/or ≥5 years spent on PD.

Polymeric nanoencapsulation of alpha interferon increases drug bioavailability and induces a sustained antiviral response in vivo.

Polymeric nanoparticulate systems allow the encapsulation of bio-active substances, giving them protection against external agents and increasing the drug's bioavailability. The use of biocompatible and biodegradable polymers usually guarantees the harmless character of the formulation, and a controlled drug release is also assured. A relatively easy procedure to obtain polymeric formulations of bioactive agents is ionotropic gelation, which allows the synthesis of chitosan (CS) - sodium tri-polyphosphate nanoparticles (NPs) loading encapsulated proteins. In this work, Bovine serum albumin (BSA) model protein and a recombinant porcine alpha interferon variant were used to obtain nanoparticulate formulations. The internalization of the encapsulated material by cells was studied using a BSA-fluorescein system; the fluorescent conjugate was observable inside the cells after 20 h of incubation. The therapeutic CS-alpha interferon formulation showed a maximum of protein released in vitro at around 90 h. This system was found to be safe in a cytotoxicity assay, while biological activity experiments in vitro showed antiviral protection of cells in the presence of encapsulated porcine alpha interferon. In vivo experiments in pigs revealed a significant and sustained antiviral response through overexpression of the antiviral markers OAS2 and PKR. This proves the preservation of porcine alpha interferon biological activity, and also that a lasting response was obtained. This procedure is an effective and safe method to formulate drugs in nanoparticulate systems, representing a significant contribution to the search for more effective drug delivery strategies.