Immunogenicity and reactogenicity of a booster dose of a novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine given to toddlers of 13-14 months of age with antibody persistence up to 31 months of age.
BACKGROUND
A combined Haemophilus influenzae type b and Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) may be a convenient alternative to separate Hib and MenC conjugate vaccines.


METHODS
Healthy infants randomized in a previous study for priming at 2, 4, and 6 months: Hib-MenC-TT primed group, 3 doses of Hib-MenC-TT + DTPa-HBV-IPV (N = 87); MenC-TT primed group, 2 doses of MenC-TT (NeisVac-C; Baxter Healthcare SA, Zuürich, Switzerland) + 3 doses of DTPa/Hib containing vaccines (N = 178); MenC-CRM primed group, 3 doses of MenC-CRM197(Meningitec; Wyeth Corporation Delaware, Madison, NJ) + DTPa-HBV-IPV/Hib (N = 93). At 13-14 months of age, Hib-MenC-TT and MenC-TT primed groups received a Hib-MenC-TT booster dose and the MenC-CRM primed group a booster dose of DTPa-HBV-IPV/Hib. Blood samples were taken before and at 1 and 18 months postbooster.


RESULTS
Before the booster dose, persistence of anti-polyribosyl ribitol phosphate (PRP) antibody concentration > or =0.15 microg/mL in the Hib-MenC-TT (96.4%) and MenC-TT (96.1%) primed groups and of MenC bactericidal titers > or =1:8 in the Hib-MenC-TT primed group (96.3%) was statistically significantly higher than in the MenC-CRM primed group (86.4% and 85.4%, respectively). One month after the Hib-MenC-TT booster, 99.2% subjects in the Hib-MenC-TT primed + MenC-TT primed pooled groups had anti-PRP levels > or =1 microg/mL, and 99.6% had SBA-MenC titers > or =1:128. The Hib-MenC-TT booster tended to be less reactogenic than the DTPa-HBV-IPV/Hib control and no serious adverse events related to vaccination were reported. Eighteen months after boosting with Hib-MenC-TT, SBA-MenC titers > or =1:8 persisted in 92.7% subjects and anti-PRP > or =0.15 microg/mL persisted in 99.4%.


CONCLUSIONS
Primary immunization with 3 doses of Hib-MenC-TT coadministered with DTPa-HBV-IPV induced antibodies that persisted up to the second year of life. The Hib-MenC-TT booster administered to primed toddlers induced robust and persistent antibody responses to both the Hib and MenC components and had an acceptable safety profile.
Móstoles Hospital, Madrid, Spain.
Juan C
JC
Tejedor
Manuel
M
Moro
José Manuel
JM
Merino
José Antonio
JA
Gómez-Campderá
Manuel
M
García-del-Rio
Antonio
A
Jurado
Francisco Javier
FJ
Díez-Delgado
Félix
F
Omeñaca
José
J
García-Sicilia
Jesús
J
Ruiz-Contreras
Ana
A
Martin-Ancel
Joan
J
Roca
Reyes
R
Boceta
Pilar
P
García-Corbeira
Gudrun
G
Maechler
Dominique
D
Boutriau
D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D018073:Haemophilus Vaccines / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D050296:Microbial Viability; D009500:Neutralization Tests; D011134:Polysaccharides / Q000276:immunology; D013745:Tetanus Toxoid / Q000009:adverse effects / Q000276:immunology*; D013997:Time Factors; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000276:immunology
D000907:Antibodies, Bacterial; D018073:Haemophilus Vaccines; C527605:Hib-MenCY-TT vaccine; D011134:Polysaccharides; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate; C008984:polyribitol phosphate