Question:medium
Mother does not transmit which of the following antibodies to the baby?
Mother does not transmit which of the following antibodies to the baby?
Show Hint
Mucosal IgA immunity does not cross the placenta.
Updated On: Jun 23, 2026
- Polio
- Diphtheria
- Measles
- Tetanus
Show Solution
The Correct Option is A
Solution and Explanation
Rule to apply: a mother hands over only IgG across the placenta, never secretory IgA. So ask which of these is protected mainly by IgA.
Diphtheria and tetanus immunity is circulating antitoxin IgG built from toxoid shots, so it crosses freely and shields the newborn. Measles passive immunity is also IgG that crosses the placenta, which is the very reason the first measles dose is held back to around nine months until that maternal antibody wanes.
Polio is the odd one out: protective immunity at the intestinal mucosa is secretory IgA, and IgA cannot cross the placenta. Therefore polio antibody is the one the mother does not effectively pass on. Note that the source recall paper duplicated Diphtheria as an option (a transcription error), corrected here to Measles without changing the answer. The mother does not transmit polio antibody. Ref: maternal immunity literature, NCBI.
Diphtheria and tetanus immunity is circulating antitoxin IgG built from toxoid shots, so it crosses freely and shields the newborn. Measles passive immunity is also IgG that crosses the placenta, which is the very reason the first measles dose is held back to around nine months until that maternal antibody wanes.
Polio is the odd one out: protective immunity at the intestinal mucosa is secretory IgA, and IgA cannot cross the placenta. Therefore polio antibody is the one the mother does not effectively pass on. Note that the source recall paper duplicated Diphtheria as an option (a transcription error), corrected here to Measles without changing the answer. The mother does not transmit polio antibody. Ref: maternal immunity literature, NCBI.
Was this answer helpful?
0
