Active vs Passive Immunity — NEET Biology
✅ Asked in NEET 2020When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation or infectious organisms gaining access into body during natural infection induce active immunity. When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity. Do you know why mother's milk is considered very essential for the new-born infant? The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. The foetus also receives some antibodies from their mother, through the placenta during pregnancy. These are some examples of passive immunity.
NTA tests whether students understand that active immunity is slow because the body must produce its own antibodies after antigen exposure, while passive immunity is immediate since ready-made antibodies are directly provided. Students often confuse which immunity is faster and forget that active immunity requires time for B cells to differentiate and secrete antibodies. The key trap: assuming immunity acquired through vaccination works instantly—it doesn't. Remember: active immunity (induced by vaccines or infection) takes days to weeks for full effect but provides long-term protection; passive immunity (mother's milk, IgA, placental antibodies) works immediately but is temporary. This distinction appears repeatedly in NEET because it tests conceptual understanding of immune response kinetics.
This paragraph was tested 2 times in NEET.
Identify the wrong statement with reference to immunity (NEET 2020)
Colostrum, the yellowish fluid, secreted by mother during the initial days of lactation is very essential to impart immunity to the newborn infants because it contains (NEET 2019)
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.