<prompt> Anti-A, anti-B, antibody appear in child ?Just after bih1 week after6 week afterAfter 6 months  <response>: Ans. is d i.e., After 6 months Titre of anti-A and anti-B antibodies is almost zero immedietly after bih. Infants sta producing anti-A and anti-B antibodies at age of 2-8 month when corresponding antigen is not present in cell. Maximum titre rech at 8 to 10 years of age after that it staed declinning. 