Vaccines cannot help an Immunocompromised person. A vaccine stimulates and trains your immune system cells like posting an APB of a criminals' photograph so that the police can identify and engage them. If you don't have cops (insert defund the police joke) the APB is utterly useless. Actually, its even worse because the traditional vaccines are weakened versions of the disease and can actually kill you because you don't have the capability to even fight a weakened version.