Answer
In this question we are dealing with artificially acquired immunity to influenza. If a healthy person contracts influenza from an infuenza patient and develops influenza. If the erstwhile healthy (second) person survives he/she will have acquired immunity to influenza by being infected with the live influenza viruses and making antibodies to overcome the infection. This is naturally acquired immunity. In our case in point the patient is vaccinated with killed/weakened influenza virus . He/she will most likely not develop influenza but his immune system will recognize, and mark the influenza antigen, and produce IgG antibodies to destroy the flu viruses Thenceforth the memory cells of this primary reaction will be quick to recognize infuenza viruses of that strain to which we say that they have been sensitized.
If the vaccinated patient is infected henceforth by this same strain of virus , it will quickly recognize the virus as an enemy that has attacked it before and quickly mount a secondary immunological response( mostly of IgM antibodies) and overcome the infection without the patient getting ill.
Work Step by Step
Vaccination produces artificially acquired immunity
