Haemophilus Influenzae Type B Vaccine

Introduction

Targets Haemophilus influenzae type b, an aerobic, fastidious, pleomorphic gram-negative coccobacillus.
Prevents invasive infections including pneumonia, meningitis, bacteremia, cellulitis, osteomyelitis, septic arthritis, and epiglottitis.
Protects highly susceptible children under two years of age.

Prepared as a polysaccharide-protein conjugate vaccine.
Chief antigen relies on capsular polysaccharide polyribosyl-ribitol-phosphate.
Polysaccharide conjugated to carrier protein converts it to a T-cell dependent antigen.
T-cell dependent response ensures robust immunity during early infancy.
Carrier proteins encompass tetanus toxoid, diphtheria toxoid, mutant diphtheria toxin CRM-197, and meningococcal outer membrane protein.
Meningococcal outer membrane protein conjugate confers rapid protection following one or two initial doses.
Utilized widely as combination vaccines, particularly pentavalent formulations containing diphtheria, pertussis, tetanus, and hepatitis B.
Hexavalent formulations further incorporate inactivated poliovirus vaccine.
Dose administration volume standardized at 0.5 milliliters.
Administered strictly via intramuscular route.
Preferred injection site identified as anterolateral aspect of mid-thigh.
Storage temperature maintained tightly between 2 to 8 degrees celsius.
Highly sensitive to freezing temperatures; do not freeze.

Universal Immunization Program recommends three primary doses at 6, 10, and 14 weeks.
Indian Academy of Pediatrics endorses primary series at 6, 10, and 14 weeks.
Booster dose required to sustain protection during the second year of life.
Booster administered between 12 to 18 months, typically at 16 to 18 months.

6 to 12 months: Two primary doses spaced 4 weeks apart, followed by one booster at 16 to 18 months.
12 to 15 months: Single primary dose followed by one booster at 16 to 18 months.
15 to 59 months: Single dose administration suffices.
Healthy children exceeding 5 years do not require catch-up vaccination.

Recommended for older children possessing specific vulnerabilities.
Indicated for functional or anatomic asplenia.
Required for human immunodeficiency virus infection, sickle cell disease, chronic cardiac disease, and chronic pulmonary disease.

Demonstrates 88 to 95 percent clinical efficacy.
Provides 90 to 100 percent protection against culture-proven invasive disease for 1 year post-vaccination.
Short term serologic correlate of protection established at 0.15 micrograms per milliliter.
Long term serologic correlate of protection determined at 1.0 microgram per milliliter.
Diminishes nasopharyngeal carriage of organism.
Confers significant herd immunity to unimmunized susceptible children.

Mild local reactions manifest as pain, redness, and swelling in 5 to 15 percent of recipients.
Fever exceeding 38 degrees celsius reported in 2 to 10 percent of cases.
Systemic symptoms like irritability and malaise rarely observed.
Contraindicated following severe allergic reaction or anaphylaxis to previous dose or vaccine components.