Classify the following scenarios as active/passive immunity and justify your answer.

Question

(a) Classify the following scenarios as active/passive immunity and justify your answer.

(i) A fetus receives antibodies from its mother through the placenta.

(ii) A person accidentally gets cut by a blade and later receives a tetanus shot.

(iii) A person receives a blood transfusion from a donor who has been vaccinated against a disease.

(b) Zoya is bitten by an infected Anopheles mosquito in the morning. In the evening, another non-infected Anopheles mosquito bites Zoya and then bites Zaheer immediately. How likely is Zaheer to get malaria? Justify your answer.

Answer 1

(a) (i) Passive immunity: Pre-formed antibodies are being transferred from the mother to the fetus as the fetus does not make its own antibodies.

(ii) Active immunity: A tetanus shot, which contains inactivated tetanus toxin, will stimulate the person's immune system to produce his own specific antibodies against tetanus.

(iii) Passive immunity: The person receiving the blood transfusion is passively acquiring antibodies from the vaccinated donor that were made by the donor's body and not the recipient's body.

(b) Zaheer is not likely/less likely get malaria.

Since Zoya has been bitten by an infected mosquito and the process of infection of the liver cells and red blood cells takes more than 5 days, the non-infected second mosquito is not likely/ less likely to get infected by biting Zoya, and thus cannot/less likely to transfer the Plasmodium to Zaheer.