• with diphtheria, tetanus and whole cell pertussis and hepatitis B vaccine (DTwP-HepB-Hib)
Partial immunoglobulin deficiency Hodgkin's disease
• with diphtheria, tetanus, acellular pertussis, hepatitis B and inactivated polio vaccine (DTaP-HepB-IPV/Hib)
Recipients of stem cell transplants Patients undergoing chemotherapy for malignant neoplasm
Efficacy
Anatomic or functional asplenia
Hib vaccines are efficacious even when administered in early infancy. Though the duration of protection following the primary series is poorly defined, in most instances, it is protective during the years of the highest susceptibility to invasive Hib disease. Other than PRP-D, all other conjugate Hib vaccines have demonstrated remarkably high, consistent efficacy and effectiveness against Hib invasive disease in a variety of settings.
Sickle cell anaemia or thalassaemia
Among conjugate Hib vaccines, only PRP-OMP is highly efficacious after a single dose. PRP-T conjugate Hib vaccine has demonstrated that following the initial dose, second and third additional doses given at 2 months intervals are required to induce high levels of immunity. After a third dose, 98-100% immunogenic response has been demonstrated even in younger infants. PRP-T conjugate Hib vaccine has demonstrated an efficacy over 95% against all invasive Hib disease and 100% efficacy against Hib pneumonia. Partly as a consequence of the effect of herd immunity induced by Hib vaccination, nasopharyngeal colonization has been drastically reduced in populations with high vaccine coverage. As a consequence of these direct and indirect effects, Hib disease has been practically eliminated in many industrialised countries and its incidence has been drastically reduced in some developing countries.
Children with nephrotic syndrome Children who have had invasive Hib disease Children under two years of age with Hib disease do not produce antibodies reliably. As such, these children need the full course of immunisation. For others, the number of doses required will depend on the age at which the first dose after the illness is given, ignoring any doses given before the illness. Re-immunisation should be initiated approximately one month after the onset of disease. Dosage and administration In general, a three dose primary series is given at the same time as the primary series of DTP. The National Immunisation Programme recommends administration of Hib vaccine at 2nd, 4th, and 6th months of life. The first dose may be given as early as 6 weeks of age and the second and 3rd doses may be given 4-8 weeks intervals along with DTP. In developed countries, a booster dose is given at 12-18 months. If immunisation is started between 6 months and one year of age, the child should receive two doses, 4-8 weeks apart. For children aged 12-24 months who have not received the primary series of Hib vaccine, one dose is sufficient.
Indications Infants and children under 5 years of age. Older children and adults who are at risk of invasive Hib disease due to following conditions: HIV/AIDS 29
All conjugate Hib vaccines should be injected deep intramuscularly. The standard dose is 0.5 ml. An immunisation series started with one type of conjugate Hib vaccine may be completed with another formulation of conjugate Hib vaccine. 30