Evaluation of immunogenicity and tolerance of single dose haemophilus influenzae type B (PRP-T) vaccine.

ABSTRACT

OBJECTIVE: Evaluation of immunogenicity and acceptability of PRP-T vaccine among the Indian children. DESIGN: Multicentric, open, parallel group, comparative study of Haemophilus influenzae type B vaccine, given as single (Group I) or associated (Group II) with DPT vaccine. SETTING: Five different vaccination clinics. SUBJECTS: 125 children between the age group of 18-24 months. PARAMETERS Measurement of (i) pre and post vaccination antibody titres of Haemophilus influenze type B specific antibody; (ii) Adverse events; and (iii) Tolerance as graded by the physician. RESULTS: Prevaccination antibody levels were > 0.15 mcg/ml in 56.3% in Group I and 35.7% in Group II. Post-seroconversion was seen in 97% in Group II receiving single and all in Group II (P > 0.05). The vaccine was well tolerated. CONCLUSIONS: The probability of subclinical infection or cross immunity is high in India. ACTHIB vaccine has a good immunogenicity and tolerance and association with DPT does not modify the immunogenicity of ACTHIB vaccine.