Efficacy of Haemophilus influenzae type b conjugate vaccine PRP-T.
Efficacy of the Haemophilus influenzae type b (Hib) conjugate vaccine PRP-T (Pasteur-Merieux) was evaluated in a controlled community intervention study in the Oxford region, UK. PRP-T was offered to infants from May 1, 1991 in three of the region's eight districts and from July 1, 1991, in a fourth district. It was given by separate injection in addition to the standard diphtheria, tetanus, and pertussis vaccine according to an accelerated 2, 3, and 4 month schedule without a booster dose in the second year of life. By October 1, 1992, more than 90% of infants in vaccine districts had received at least one dose of PRP-T. None of the infants given three doses had developed Hib infection, whereas 11 infections occurred in the control population (vaccine efficacy 100%, 95% CI 80-100%). Intention-to-treat analysis also showed a high estimate of efficacy for the vaccine (90%, 50-99%). Follow-up of study children until November 1, 1993, has shown only 1 vaccine failure in an infant, and no invasive infections in those older than 1 year (average age 22 months). PRP-T vaccine had high protective efficacy with an accelerated immunisation schedule. Furthermore, the vaccine appears to remain protective through the second year of life without a booster dose. These findings provide encouragement for use of PRP-T in the Expanded Programme of Immunisation.
Booy
R
R
Department of Paediatrics, Oxford Radcliffe Hospital, Headington, UK.
Hodgson
S
S
Carpenter
L
L
Mayon-White
R T
RT
Slack
M P
MP
Macfarlane
J A
JA
Haworth
E A
EA
Kiddle
M
M
Shribman
S
S
Roberts
J S
JS
D002675:Child, Preschool; D006192:Haemophilus Infections / Q000453:epidemiology / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000008:administration & dosage; D006193:Haemophilus influenzae; D006801:Humans; D007115:Immunization Schedule; D015994:Incidence; D007223:Infant; D011446:Prospective Studies; D013745:Tetanus Toxoid / Q000008:administration & dosage; D006113:United Kingdom / Q000453:epidemiology
D018073:Haemophilus Vaccines; C055753:Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate; D013745:Tetanus Toxoid