Severe illness at the scheduled time of vaccination warrants a delay, but minor illnesses such
as colds, coughs or low-grade fevers do not. Children with minor illnesses of this sort
respond normally to vaccination and have no added side effects.
Parents should discuss with their child's doctor whether to postpone vaccination if their
child has had a hypotonic-hyporesponsive episode (HHE) after a previous dose of pertussis
vaccine. Although no permanent damage has followed any HHE associated with pertussis
vaccination, delaying vaccination may be an alternative if the frequency of pertussis in the
family's community is known to be low. If pertussis is occurring, it would be better for the
child to be vaccinated.
Pertussis vaccination is often deferred in children with progressive or changing neurologic
conditions. Such conditions include tuberous sclerosis, recurrent convulsions that are not
prevented by medication, and neurodegenerative diseases. The reason for deferral is to avoid
introducing a variable (e.g., the vaccine) that may be viewed as causing changes in the child
that otherwise would be attributed to the disorder. Deferral should be reassessed at each visit
to the doctor; pertussis vaccine should be given when the condition has resolved, been
corrected or controlled.
If pertussis vaccine is withheld, diphtheria and tetanus toxoids can still be administered
without the pertussis vaccine.
Anyone who has received immune globulin by injection into muscle or a vein should not
receive measles, mumps or rubella vaccine for three months or more, depending on the dose of
immune globulin. The antibodies in the immune globulin can interfere with establishment of
immunity after vaccination.