Antibodies maternally-acquired

Maternally acquired antibodies will react not only with antigen associated with a threatening infection but also with antigens introduced to the body as part of an immunization programme. Premature immunization, i.e. before degradation and... 

The age of the recipient is another important determining factor in vaccine and toxoid response. In the first few months of life, maternal antibodies acquired via transplacental transfer during the third trimester of gestation protect an infant. However, the maternal antibody also inhibits the immune response to live vaccines because the circulating antibodies neutralize the vaccine before the infant has the opportunity to mount an immune response. For this reason, live vaccines are not administered until maternal antibody has waned, generally by age 12 months. ... 

The measles vaccine is administered subcutaneously as a0.5-mL dose in the arm (or in the thigh if the patient is younger than 15 months of age). The vaccine is administered routinely for primary immunization to persons 12 to 15 months of age, usually as the MMR vaccine. The measles vaccine is not administered earlier than 12 months (except in certain outbreak circumstances) because persisting maternal antibody that was acquired transplacentally late in gestation can neutralize the vaccine virus before the vaccinated person can mount an immune response. A second dose of MMR is recommended when... 

Passive immunity is induced by injection of serum taken from an individual already immune to a particular antigen it can also be acquired by the transfer of maternal antibodies to offspring via the placenta or breast milk (seecolostrum). Active immunity tends to be long-lasting passive immunity is short-lived. See also autoimmunity. 

Once an individual has become immune through previous infection, vaccination, or by passive transmission of maternal antibody, these specific defenses effectively control most viral and bacterial pathogens. Depletion of the CD4+ T-lymphocyte population, as occurs in acquired immunedeficiency syndrome (AIDS) leads to a general reduction in immune competence and an increased susceptibility to infectious and neoplastic disease (22). Similarly, IgA deficiency can result in increased risk of respiratory tract infection (23). 

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