BOOSTER VACCINATION AGAINST SARS-CoV-2: CURRENT CHALLENGES AND SOLUTIONS.

The COVID-19 pandemic is going on, which makes it crucial to prevent the spread of coronavirus disease. Vaccination is the only way of specific prevention of COVID-19. The SARS-CoV-2 virus is continuously evolving and new variants appear. Moreover, the effectiveness of protective immunity after vaccination tends to decrease over several months. Booster vaccination may be the solution to these problems. The booster is an extra vaccination that helps to reactivate the immunity against COVID-19. Booster doses can be homologous (the same as the primary vaccine) and heterologous (different from the primary vaccine). It is of current interest to study heterologous vaccination as the injection of different vaccines may result in a more intense immune response. Furthermore, the same vaccine may not be available at the time of booster vaccination. This review is aimed at summarizing the key research findings in the field of booster vaccination against COVID-19.Copyright © 2022 Booster vaccination against. All rights reserved.

Multiplatform analyses reveal distinct drivers of systemic pathogenesis in adult versus pediatric severe acute COVID-19.

The pathogenesis of multi-organ dysfunction associated with severe acute SARS-CoV-2 infection remains poorly understood. Endothelial damage and microvascular thrombosis have been identified as drivers of COVID-19 severity, yet the mechanisms underlying these processes remain elusive. Here we show alterations in fluid shear stress-responsive pathways in critically ill COVID-19 adults as compared to non-COVID critically ill adults using a multiomics approach. Mechanistic in-vitro studies, using microvasculature-on-chip devices, reveal that plasma from critically ill COVID-19 adults induces fibrinogen-dependent red blood cell aggregation that mechanically damages the microvascular glycocalyx. This mechanism appears unique to COVID-19, as plasma from non-COVID sepsis patients demonstrates greater red blood cell membrane stiffness but induces less significant alterations in overall blood rheology. Multiomics analyses in pediatric patients with acute COVID-19 or the post-infectious multi-inflammatory syndrome in children (MIS-C) demonstrate little overlap in plasma cytokine and metabolite changes compared to adult COVID-19 patients. Instead, pediatric acute COVID-19 and MIS-C patients show alterations strongly associated with cytokine upregulation. These findings link high fibrinogen and red blood cell aggregation with endotheliopathy in adult COVID-19 patients and highlight differences in the key mediators of pathogenesis between adult and pediatric populations.

SARS-CoV-2 escape from cytotoxic T cells during long-term COVID-19.

Evolution of SARS-CoV-2 in immunocompromised hosts may result in novel variants with changed properties. While escape from humoral immunity certainly contributes to intra-host evolution, escape from cellular immunity is poorly understood. Here, we report a case of long-term COVID-19 in an immunocompromised patient with non-Hodgkin's lymphoma who received treatment with rituximab and lacked neutralizing antibodies. Over the 318 days of the disease, the SARS-CoV-2 genome gained a total of 40 changes, 34 of which were present by the end of the study period. Among the acquired mutations, 12 reduced or prevented the binding of known immunogenic SARS-CoV-2 HLA class I antigens. By experimentally assessing the effect of a subset of the escape mutations, we show that they resulted in a loss of as much as ~1% of effector CD8 T cell response. Our results indicate that CD8 T cell escape represents a major underappreciated contributor to SARS-CoV-2 evolution in humans.

BOOSTER VACCINATION AGAINST SARS-CoV-2: CURRENT CHALLENGES AND SOLUTIONS

The COVID-19 pandemic is going on, which makes it crucial to prevent the spread of coronavirus disease. Vaccination is the only way of specific prevention of COVID-19. The SARS-CoV-2 virus is continuously evolving and new variants appear. Moreover, the effectiveness of protective immunity after vaccination tends to decrease over several months. Booster vaccination may be the solution to these problems. The booster is an extra vaccination that helps to reactivate the immunity against COVID-19. Booster doses can be homologous (the same as the primary vaccine) and heterologous (different from the primary vaccine). It is of current interest to study heterologous vaccination as the injection of different vaccines may result in a more intense immune response. Furthermore, the same vaccine may not be available at the time of booster vaccination. This review is aimed at summarizing the key research findings in the field of booster vaccination against COVID-19. © 2022 Booster vaccination against. All rights reserved.

Genomic epidemiology of the early stages of the SARS-CoV-2 outbreak in Russia.

The ongoing pandemic of SARS-CoV-2 presents novel challenges and opportunities for the use of phylogenetics to understand and control its spread. Here, we analyze the emergence of SARS-CoV-2 in Russia in March and April 2020. Combining phylogeographic analysis with travel history data, we estimate that the sampled viral diversity has originated from at least 67 closely timed introductions into Russia, mostly in late February to early March. All but one of these introductions were not from China, suggesting that border closure with China has helped delay establishment of SARS-CoV-2 in Russia. These introductions resulted in at least 9 distinct Russian lineages corresponding to domestic transmission. A notable transmission cluster corresponded to a nosocomial outbreak at the Vreden hospital in Saint Petersburg; phylodynamic analysis of this cluster reveals multiple (2-3) introductions each giving rise to a large number of cases, with a high initial effective reproduction number of 3.0 [1.9, 4.3].