ABSTRACT
Background: SARS-CoV-2 vaccines have led to reduced transmission rates and a decrease of severe COVID-19. The combination of waning immunity over time and the emergence of highly transmissible variants, have led to breakthrough infections in vaccinated individuals. A third vaccine dose improves the short-term immune response and protection from infection, yet the long-term effect is unknown. Aim(s): To assess the humoral response to three doses of the BNT162b2 (Pfizer-BioNTech) vaccine over one-year. Method(s): A prospective observational study in vaccinated healthcare workers (HCW). IgG anti-S (spike) titers were measured over one year at six time points: 0-5 days before-, and 1, 3, 6, 9, and 12 months after the second vaccine dose, (which is 5-6 months after the third dose). Result(s): Seventy-six HCW had antibody titers measurements from all six time points. IgG anti-S titers significantly increased after the third dose, from a median of 135AU/ml to >400AU/ml in all cases (p<0.001). The last tests were taken a median of 359 days after the second dose and 148 after the third. IgG anti-S levels at the last test were 345AU/ml, significantly higher than all measurements before the third dose (p<0.001). Conclusion(s): A third dose of BNT162b2 was associated with a meaningful increase in anti-S Ab levels in HCW, which, despite declining, remained significantly higher than previous measurements for up to 5 months of follow-up.
ABSTRACT
TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to challenge the world. Even though effective vaccines have been developed, new variants of concern continue to emerge. While there is evidence of higher transmissibility rates of the B.1.1.7 variant and other variants, concerns regarding disease severity of these variants have not yet been confirmed. Patients undergoing maintenance hemodialysis are at increased risk for infection, with several reports of COVID-19 outbreaks in hemodialysis centers. The clinical outcomes of the SARS-CoV-2 variant viruses have not been reported or compared to non-variant SARS-CoV-2 among this unique population. The goal of the study was to compare the clinical outcomes and related mortality of infection with variant SARS-CoV-2 in chronic hemodialysis patients, and to compare it with infection by previous, non-variant strains of the virus. METHODS: This is a retrospective observational study comparing COVID-19 outbreaks of variant and non-variant SARS-CoV-2 strains in 2 hemodialysis centers in Israel. In one dialysis center ("center 1") an outbreak of COVID-19 caused by variant SARS-CoV-2 occurred starting from 28 December 2020. Subjects from a second hemodialysis center ("center 2") infected by non-variant SARS-CoV-2 in an earlier outbreak of COVID-19 which occurred from April 2020 to July 2020 served as control group. Complete SARS-CoV-2 genomes were sequenced via next generation sequencing (NGS).Primary outcome measures were 30-days mortality rates and in-hospital mortality rates. Secondary outcomes included mortality rates during follow-up, disease severity (according to NIH guidelines), need for respiratory support, type of respiratory support and need for hemodynamic support. RESULTS: Baseline subjects' characteristics were comparable. Chronic hemodialysis patients infected with SARS-CoV-2 variants had more severe infection and required more respiratory support, such as NIV (p=0.05), HFOT (p=0.021) and mechanical ventilation (p=0.05), as well as more hemodynamic support (p=0.05). Among patients from center 1, who were infected with virus variants, 71% were classified as critical vs. 8% of patients from center 2 (non-variant, p=0.005). 30-day mortality was higher among patients from center 1 as compared to center 2 (57.1% vs. 7.7.%, odds ratio for 30-day mortality in center 1 was 16, with 95% confidence interval 2-128, p=0.003).Multivariate analysis model for predictors of all-cause mortality showed that infection with a variant was the most important predictor of mortality. CONCLUSIONS: Infection with variant SARS-CoV-2 among chronic hemodialysis patients was strongly related with severe disease and mortality. CLINICAL IMPLICATIONS: SARS-CoV-2 genetic variation may affect clinical outcomes. Vaccination of hemodialysis patients should be prioritized. DISCLOSURES: No relevant relationships by sydney Benchetrit, source=Web Response No relevant relationships by keren cohen, source=Web Response No relevant relationships by Ayman Fadeela, source=Web Response No relevant relationships by Orna Mor, source=Web Response no disclosure on file for Naomi Nacasch;No relevant relationships by ori wand, source=Web Response no disclosure on file for Neta Zuckerman;