With regards to T cell responses, we observed that at 1 month post-infection 98.9% and 100.0% had a S-specific CD4 + and CD8 + T cell response, respectively, while at ten months post-infection, 89.7% and 93.8% had maintained a S-specific CD4 + and CD8 + T cell response, respectively. This evidence concerns the gene CD4 and infection.