Questions 31-37 complete the summary
Write NO MORE THAN TWO WORDS for each answer.
Every day the human body is fighting off 31 . by destructive pathogens. A person in good health has natural protection in the form of an immune system which works best against familiar micro-organisms which may have been encountered during a previous 32 or passed on by the mother before or after birth
Vaccination is a way to cause 33 Immunization by introducing a small amount of pathogen into body- just enough for the bodys 34 . To react by making antibodies. Passive immunization can be used as a way of treating someone who is already sick. Proteins from animals 35 . are introduced into the patient to give him the necessary antibodies to fight the disease.