Biology · Human Health and Diseases · NEET
| When it occurs | On FIRST contact with the pathogen | On LATER contact with the SAME pathogen |
| Speed | Slow to appear | Fast (rapid) |
| Strength / antibody level | Low, weak | High, highly intensified |
| Other name | First response | Anamnestic response |
| Role of memory cells | Memory cells are FORMED here | Memory cells are USED to respond quickly |
| Type of immunity | Acquired immunity | Acquired immunity |
The primary response happens on the FIRST contact with a pathogen. It is slow and produces a low level of antibodies. The secondary (anamnestic) response happens on LATER contact with the SAME pathogen. It is fast and produces a much higher level of antibodies. Both belong to acquired immunity, not innate immunity.
Anamnestic response is just another name for the secondary immune response. The word 'anamnestic' means 'remembering'. It is the fast, strong reaction the body gives when it meets the same pathogen a second time, because it remembers the first encounter. NEET has directly asked this word (NEET 2022), so learn that anamnestic = secondary response.
During the first (primary) contact, the body makes memory B-cells and memory T-cells. These memory cells stay in the body for a long time. When the same pathogen returns, memory cells recognise it at once and quickly make large numbers of antibodies. So the secondary response is faster and stronger than the primary response.
Memory cells are special B-lymphocytes and T-lymphocytes formed after the first exposure to a pathogen. They 'store' the memory of that pathogen. They are the reason vaccination works: a vaccine gives a safe first exposure, so memory cells are ready to fight the real pathogen later. NEET links this to both immune response and vaccination.
Memory is a feature of ACQUIRED (adaptive) immunity only. Innate immunity is non-specific, present at birth, and has NO memory. This is a very common NEET trap: if an option says innate immunity has memory or gives a secondary response, that option is WRONG.
Both responses are carried out by two types of lymphocytes: B-lymphocytes and T-lymphocytes. B-cells produce antibodies (humoral response) and T-cells help and coordinate the attack (cell-mediated response). NCERT states the primary and secondary responses are carried out with the help of these two special lymphocytes.
Select the incorrect statement with respect to acquired immunity:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes. Anamnestic response and secondary response mean exactly the same thing. It is the fast, strong reaction on the second contact with the same pathogen.
The secondary response is much stronger and faster. It makes a higher level of antibodies because memory cells are already present from the first exposure.
Both belong to acquired (adaptive) immunity, because only acquired immunity has memory. Innate immunity has no memory and no secondary response.
A vaccine gives a safe first exposure that creates memory B and T-cells. When the real pathogen enters later, these memory cells trigger a fast, strong secondary response, so you do not fall sick.
Memory B-lymphocytes and memory T-lymphocytes give the memory. They are formed during the primary response and stay in the body for a long time.
