Question: 4. William G. Was Well For The First Ten Months Of His Life, But In The Following Year He Had Pneumonia Once, Several Cases Of Otitis Media And A Streptococcal Infection Of The Skin. All Of These Infections Were Treated Successfully With Antibiotics. William Was A Bright, Active Child Who Gained Weight, Grew, Developed Normally But Continued To Have …

4. William G. was well for the first ten months of his life, but in the following year he had pneumonia once, several cases of otitis media and a streptococcal infection of the skin. All of these infections were treated successfully with antibiotics. William was a bright, active child who gained weight, grew, developed normally but continued to have repeated bacterial infections of the ears, sinuses and had pneumonia two more times before reaching the age of 30 months. Family history revealed that William’s mother had two brothers who died by the age of two due to repeated pneumonia infections. At this point William’s physician tested his serum immunoglobulins with the following results: IgG 80 (normal 600 – 1500), IgA 0 (normal 50 – 125), IgM 10 (normal 75 – 150). William was prescribed monthly injections of gamma globulins to maintain a minimum level of IgG of 200. William started school at age five, though had prolonged absences due to recurrent pneumonia and other bacterial infections. At age nine he was referred to a specialist due to partial lung collapse and chronic cough. The physician noted William had no visible tonsils in spite of the fact he never had had a tonsillectomy, but was otherwise normal for his age. William eventually was diagnosed with X-linked agammaglobulinemia, a condition characterized by a lack of mature B cells. a. Explain why do people with agammaglobulinemia have more trouble fighting bacterial infections than viral infections? (2 pts) b. What might be the likely explanation for the fact that William was well for the first ten months of his life? (2 pts) c. Explain why does William have to receive monthly injections of gammaglobulins and not just a single injection? (2 pts) 3. Indicate whether the following situations are examples of passive (P) or active (A). immunity. (5 pts) A 1. An individual receives Sabin polio vaccine P 2. Antibodies migrate through a pregnant woman’s placenta into the vascular system of her fetus. P 3. “Borrowed” immunity – immunity provided from another source _A__4. Immunolgic memory is provided A 5. An individual suffers through chickenpox