Answer:Vaccines are responsible for the control of many infectious diseases that were once common in this country, including polio, measles, diphtheria, pertussis (whooping cough), rubella (German measles), mumps, tetanus, and Haemophilus influenzae type b (Hib).
Explanation:
Answer: Bacteria
Explanation:
Invasive bacteria such as Salmonella , listeria,yersinia And Mycobacterium Have been used as vaccine vector