HIV is a virus which attacks the immune system and causes a lifelong severe illness with a long incubation period. The end-stage of the infection, acquired immunodeficiency syndrome (AIDS), results from the destruction of the immune system.
Rabies is a disease caused by rabies virus (a Lyssavirus). Every year, a small number of cases of rabies is reported in Europe - travel-related or autochthonous.
Diphtheria is spread through droplets from coughing or sneezing. Most often the disease causes a sore throat and low grade fever in the first few days of the illness.