Effectiveness and safety of an Haemophilus influenzae type b conjugate vaccine (PRP-T) in young infants. Kaiser-UCLA Vaccine Study Group.
OBJECTIVE
To study the safety, immunogenicity, and protective efficacy of the Haemophilus influenzae capsular polysaccharide tetanus conjugate vaccine (PRP-T).


METHODS
Randomized, double-blind, controlled clinical trial.


METHODS
Southern California Kaiser-Permanente Health Plan.


METHODS
10,317 infants 6 to 15 weeks of age, with no known immune dysfunction, exposure to hepatitis B, or contraindication to diphtheria-tetanus-pertussis (DTP) vaccination were enrolled between August 1989 and September 1990.


METHODS
Infants were randomized to receive either PRP-T or a recombinant hepatitis B control vaccine (in addition to DTP) at approximately 2, 4, and 6 months of age.


METHODS
Adverse reactions occurring during the first 72 hours and between doses (including hospitalizations and outpatient visits) were measured using parental reporting/interviews and review of records. Invasive disease caused by H influenzae was ascertained from the time of enrollment until December 31, 1990.


RESULTS
In October 1990, the study was prematurely terminated because of licensure of other H influenzae vaccines recommended for routine infant use. The rates of systemic and local reactions occurring within 72 hours of each vaccine dose were generally similar for infants given PRP-T and hepatitis B, but some reaction rates (local reactions, fever > or = 102 degrees F, irritability, crying) were significantly higher in the PRP-T group. In the month following receipt of vaccine, PRP-T-vaccinated infants experienced five definite seizures compared with three in the hepatitis B control group. Within 48 hours of vaccination, three seizures (two definite and one possible), which were thought to be related to vaccination, occurred in the PRP-T group, compared with none in the control group (P < .13). Overall morbidity, mortality, and hospitalization rates were similar in the two vaccine groups. Three cases of invasive disease caused by H influenzae occurred in the control group; none occurred in the PRP-T group.


CONCLUSIONS
The PRP-T vaccine is safe and appears to be effective in preventing invasive disease caused by H influenzae type b.
Vadheim
C M
CM
UCLA Center for Vaccine Research, Harbor-UCLA Medical Center, Torrance 90502.
Greenberg
D P
DP
Partridge
S
S
Jing
J
J
Ward
J I
JI
D001428:Bacterial Vaccines / Q000009:adverse effects* / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D018073:Haemophilus Vaccines; D017325:Hepatitis B Vaccines / Q000009:adverse effects; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D012640:Seizures / Q000209:etiology; D013745:Tetanus Toxoid / Q000009:adverse effects* / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000009:adverse effects
D001428:Bacterial Vaccines; D018073:Haemophilus Vaccines; C055753:Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate; D017325:Hepatitis B Vaccines; D013745:Tetanus Toxoid; D014614:Vaccines, Synthetic