A previously healthy 8-year-old boy is infected with an upper respiratory tract virus for the first time.During the first few hours of infection,which one of the following events occurs?
A)The adaptive immune system responds rapidly to the virus and keeps the viral infection under control.
B)The innate immune system responds rapidly to the viral infection and keeps the viral infection under control.
C)Passive immunity mediated by maternal antibodies limits the spread of infection.
D)B and T lymphocytes recognize the virus and stimulate the innate immune response.
E)The virus causes malignant transformation of respiratory mucosal epithelial cells,and the malignant cells are recognized by the adaptive immune system.

Question

Quizplus · Accepted Answer

The innate immune response to microbes develops within hours of infection,well before the adaptive immune response.B and T lymphocytes are components of the adaptive immune response,and they would not be able to respond to a newly encountered virus before the innate immune response.An 8-year-old boy would no longer have maternal antibodies from transplacental passive transfer and is unlikely to be breast-feeding,which is another potential source of maternal antibodies.Malignant transformation takes months or years to develop.

A Previously Healthy 8-Year-Old Boy Is Infected with an Upper