by Max Gelman

US government reportedly begins preparing for Covid-19 challenge trials. Are they ethical?

Controversial human challenge trials for potential Covid-19 vaccines reportedly have a new booster — the US government. Scientists working for the government have begun manufacturing a strain of the novel coronavirus that could be used in such studies, Reuters reported Friday morning. The trials would enroll healthy volunteers to be…, Read More

by Gauttier, V., Morello, A., Girault, I., Mary, C., Belarif, L., Desselle, A., Wilhelm, E., Bourquard, T., Pengam, S., Teppaz, G., Thepenier, V., Biteau, K., De Barbeyrac, E., Kiepferle, D., Vasseur, B., Le Flem, F.-X., Debieuvre, D., Costantini, D., Poirier, N.

Tissue-resident memory CD8 T-cell responses elicited by a single injection of a multi-target COVID-19 vaccine

The COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) which enters the body principally through the nasal and larynx mucosa and progress to the lungs through the respiratory tract. SARS-CoV-2 replicates efficiently in respiratory epithelial cells motivating the development of alternative and rapidly scalable vaccine inducing mucosal protective and long-lasting immunity. We have previously developed an immunologically optimized multi-neoepitopes-based peptide vaccine platform which has already demonstrated tolerance and efficacy in hundreds of lung cancer patients. Here, we present a multi-target CD8 T cell peptide COVID-19 vaccine design targeting several structural (S, M, N) and non-structural (NSPs) SARS-CoV-2 proteins with selected epitopes in conserved regions of the SARS-CoV-2 genome. We observed that a single subcutaneous injection of a serie of epitopes induces a robust immunogenicity in-vivo as measured by IFN{gamma} ELIspot. Upon tetramer characterization we found that this serie of epitopes induces a strong proportion of virus-specific CD8 T cells expressing CD103, CD44, CXCR3 and CD49a, the specific phenotype of tissue-resident memory T lymphocytes (Trm). Finally, we observed broad cellular responses, as characterized by IFN{gamma} production, upon restimulation with structural and non-structural protein-derived epitopes using blood T cells isolated from convalescent asymptomatic, moderate and severe COVID-19 patients. These data provide insights for further development of a second generation of COVID-19 vaccine focused on inducing lasting Th1-biased memory CD8 T cell sentinels protection using immunodominant epitopes naturally observed after SARS-CoV-2 infection resolution.,Read More