A prospective study with more than 1700 participants (1256 HD patients, 368 KTR patients, 144 healthy controls) revealed similar rates of seroconversion after two doses of mRNA vaccine in HD patients and HC (>95%), while the KTR seroconversion rate was only 42%, with lower frequencies of SARS-CoV-2 reactive CD4+ T helper cells [31]. This evidence concerns the gene CD4 and Huntington disease.