The MMR vaccine gives protection against measles, mumps and rubella. How? (4 marks)

. Vaccine contains antigens from the pathogens . This is recognised by helper T cells which activates other helper T cells and B cells . B cells undergo clonal selection and produce memory + plasma cells . Plasma cells produce antibodies that have a binding site that is complimentary to the shape of the antigen . If the individual were to be infected, then a secondary response would take place and symptoms would not be felt.