$INO I’ve always felt that generating a protective response against SARS-CoV2 is not all that difficult. The reason being that a lot of cross reactive T-cell activity to other coronaviruses is already present in a large swath of the world’s population. It is why mRNA vaccines, imo, showed such high efficacy against the original strain. It is also why I believe CD8+T-cell-boosting vaccines, like INO-4800, should do well: “Our results, based on specific tetramer binding, provide evidence supporting the presence of frequent cross-reactive CD8 T cells to SARS-CoV-2 antigens in non-exposed individuals.”