MI2.1-8 | Immunology: Basic, Applied & Immunological Disorders — Practice Quiz

A 28-year-old patient presents with high fever and productive cough for 5 days. Sputum culture grows Streptococcus pneumoniae. Which immunological mechanism provides the most effective primary defence against this extracellular encapsulated bacterium?

A student reads that IgM appears first after primary infection, whereas IgG appears later and persists. Which structural feature of IgM best explains its superior early complement activation ability?

A tuberculin (Mantoux) test is performed on a nursing student who has received BCG vaccination. At 72 hours, she shows 14 mm of induration. Which cells mediate this reaction?

A 5-year-old child in Rajasthan is brought with fever and rash after exposure to a dengue cluster. Dengue NS1 antigen and IgM are positive. Which type of immune response provides the most effective long-term protection after recovery?

A laboratory reports an ELISA result as 'reactive for anti-HIV antibodies' in a sample sent from a blood bank. Which principle underlies ELISA in this context?

A 22-year-old medical student is given a booster dose of hepatitis B vaccine 10 years after primary vaccination. Two weeks later, her anti-HBs titre rises rapidly to protective levels. Which immunological phenomenon best explains this rapid anamnestic response?

A 35-year-old asthmatic patient develops severe bronchospasm within 15 minutes of receiving amoxicillin-clavulanate injection. Which cell type and mediator are primarily responsible for this immediate reaction?

A 4-year-old boy has had four episodes of pneumococcal sepsis and one episode of Haemophilus influenzae meningitis. His serum immunoglobulins show: IgG 120 mg/dL (normal: 540-1822), IgA undetectable, IgM undetectable. Pre-B cells are present in bone marrow. Which diagnosis best fits?

India launched the Human Papillomavirus (HPV) vaccine (Cervarix/Gardasil) for adolescent girls. The vaccine protects against HPV serotypes 16 and 18 which cause 70% of cervical cancers. This vaccine is best classified as:

A VDRL test returns a high titre positive in a 25-year-old woman attending antenatal care. A confirmatory TPHA (Treponema pallidum haemagglutination assay) is negative. Which is the most likely explanation?