This is why behaviour modifications were and are suggested during epidemics: “The virus dissemination observed in our case study may indicate that patients with an impaired immune system have a decreased ability to eliminate the virus.”<p>Those with a weakened or nonexistent immune system are always at risk. Need an immune system to utilize a vaccine. They could be elderly, HIV-positive, transplant patients, ,,, All we can do to protect them is reduce the chance they catch the thing. And buy time until some treatment presents itself.<p>Oh, and it’s good to avoid creating people who get infected for a long period of time. Increases the evolutionary pressure on the disease, which hurts everybody.