CAPE Biology Unit 2 · 2018 · Paper 2 · Question 6(b)

Joseph contracts dengue fever and recovers. Three months later, he goes to another town to take care of his grandmother who is suffering from dengue fever. He decides to take her to the hospital where both his blood and his grandmother’s blood are tested. The antibody concentration of Joseph’s blood is found to be abnormally high, even though he does not have any symptoms of the disease. Discuss why Joseph’s immune response is heightened even though he does not appear ill.