Fill in the Blanks Pathogens Fill inOnline version 8.L.1.1 Fill in by Nicole Weissert 1 immune vaccine Bacteria host mutate are living pathogens that can be treated with antibiotics . Viruses are non - living pathogens that need a to reproduce . Parasites are living pathogens that feed off nutrients from a host . Fungi are living single or multicellular pathogens like yeast or mushrooms . A is a weakened version of a virus or bacteria that is injected to trigger the system . Antibodies are produced by the immune system to fight off harmful germs . Viruses can change or , causing us to have to get vaccines every year .