HAEMOPHILUS INFLUENZAE TYPE B (Hib) VACCINE

Hib vaccine protects against Haemophilus influenzae type B infection.

Haemophilus influenzae type b (Hib) causes meningitis and other severe infections (e.g., pneumonia, bacteremia, septic arthritis, and epiglottitis) primarily among infants and children <5>

All infants should receive a primary series of conjugate Hib vaccine beginning at age 2 months. The number of doses in the primary series depends on the type of vaccine used. A primary series of PRP-OMP vaccine is two doses; HbOC and PRP-T require a three-dose primary series. A booster should be given at age 12-15 months, regardless of which vaccine is used for the primary series.

Recommended Haemophilus influenzae type b (Hib) routine

Vaccine	2 Months	4 Months	6 Months	12-15 Months
HbOC/PRP-T	Dose 1	Dose 2	Dose 3	Booster
PRP-OMP	Dose 1	Dose 2	�	Booster

The optimal interval between doses is 2 months, with a minimum interval of 1 month. At least 2 months should separate the booster dose from the previous (second or third) dose. Hib vaccines may be given simultaneously with all other vaccines.

Limited data suggest that Hib conjugate vaccines given to infants <6>

All three conjugate Hib vaccines licensed for use in infants are interchangeable. If it is necessary to change the type of vaccine, three doses of any combination constitute the primary series. Any licensed conjugate vaccine may be used for the booster dose regardless of what type was received in the primary series.

Unvaccinated infants and children ages 7 months and older might not require a full series of three or four doses (Table 8-2). The number of doses an infant or a child needs to complete the series depends on the infant's or child's age and, to a lesser degree, on the number of prior doses of Hib vaccine received. Previously unvaccinated children 15-59 months of age should receive a single dose of any conjugate Hib vaccine. In general, children >59 months of age do not need Hib vaccination. Refer to the American Academy of Paediatrics Red Book for additional information on late or lapsed Hib vaccination schedules.

Adverse Reactions

Adverse events following vaccination with Hib conjugates are uncommon. Swelling, redness, or pain, or a combination of these, have been reported in 5%-30% of recipients and usually resolve within 12-24 hours. Systemic reactions such as fever and irritability are infrequent.

Precautions and Contraindications

Vaccination with Hib conjugate vaccine is contraindicated in anyone known to have experienced anaphylaxis following a prior dose of that vaccine. Vaccination should be delayed in infants and children with moderate or severe acute illnesses. Minor illnesses (for example, mild upper respiratory infection) are not contraindications to vaccination. Contraindications and precautions for the use of TriHIBit and Comvax are the same as those for their individual component vaccines (i.e., DTaP, Hib, and hepatitis B).