Which vaccine must be delayed for 11 months after administering gamma globulin to a child?

When a child receives gamma globulin, it can interfere with the immune response to certain live attenuated vaccines, particularly the measles, mumps, and rubella (MMR) vaccine. Gamma globulin provides passive immunity, which can potentially diminish the effectiveness of a vaccine that relies on the body’s immune system to produce a response.

The recommendation to delay the administration of the MMR vaccine for 11 months after the administration of gamma globulin is rooted in ensuring that the immune system can mount an adequate response to the vaccine, achieving the desired protective immunity against these viral infections. In contrast, other vaccines, such as diphtheria, tetanus, pertussis, hepatitis B, and inactivated polio virus, do not have the same interference when given after gamma globulin, allowing them to be administered without the same precaution. Thus, delaying the MMR vaccination helps to optimize the immunological benefit for the child.