Covid Early Treatment & Vac Safety Scientific Studies

 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3897733 Abstract Background: Data on breakthrough SARS-CoV-2 Delta variant infections are limited. Methods: We studied breakthrough infections among healthcare workers of a major infectious diseases hospital in Vietnam. We collected demographics, vaccination history and results of PCR diagnosis alongside clinical data. We measured SARS-CoV-2 (neutralizing) antibodies at diagnosis, and at week 1, 2 and 3 after diagnosis. We sequenced the viruses using ARTIC protocol. Findings: Between 11th–25th June 2021 (week 7–8 after dose 2), 69 healthcare workers were tested positive for SARS-CoV-2. 62 participated in the clinical study. 49 were (pre)symptomatic with one requiring oxygen supplementation. All recovered uneventfully. 23 complete-genome sequences were obtained. They all belonged to the Delta variant, and were phylogenetically distinct from the contemporary Delta variant sequences obtained from community transmission cases, sugges...

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4516275/ RESEARCH ARTICLE Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens Andrew F. Read1,2*, Susan J. Baigent3 , Claire Powers3 , Lydia B. Kgosana3 , Luke Blackwell3 , Lorraine P. Smith3 , David A. Kennedy1,2, Stephen W. Walkden-Brown4 , Venugopal K. Nair3 1 Center for Infectious Disease Dynamics, Departments of Biology and Entomology, The Pennsylvania State University, University Park, Pennsylvania, United States of America, 2 Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America, 3 Avian Oncogenic Virus Group, The Pirbright Institute, Compton, Newbury, Berkshire, United Kingdom, 4 School of Environmental and Rural Science, The University of New England, Armidale, Australia * a.read@psu.edu Abstract Could some vaccines drive the evolution of more virulent pathogens? Conventional wisdom is that natural selection will remove highly lethal pathogens if ho...

 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250780 The spike protein receptor-binding domain (RBD) of SARS-CoV-2 is the molecular target for many vaccines and antibody-based prophylactics aimed at bringing COVID-19 under control. Such a narrow molecular focus raises the specter of viral immune evasion as a potential failure mode for these biomedical interventions. With the emergence of new strains of SARS-CoV-2 with altered transmissibility and immune evasion potential, a critical question is this: how easily can the virus escape neutralizing antibodies (nAbs) targeting the spike RBD? To answer this question, we combined an analysis of the RBD structure-function with an evolutionary modeling framework. Our structure-function analysis revealed that epitopes for RBD-targeting nAbs overlap one another substantially and can be evaded by escape mutants with ACE2 affinities comparable to the wild type, that are observed in sequence surveillance data and infect cel...