Antibody persistence 5 years after vaccination at 2 to 10 years of age with Quadrivalent MenACWY-CRM conjugate vaccine, and responses to a booster vaccination.
BACKGROUND
In a multi-center extension study, children 2-10 years of age, initially vaccinated with one or two doses (2-5 year-olds) or one dose (6-10 year-olds) of quadrivalent meningococcal CRM197-conjugate vaccine (MenACWY-CRM), were assessed five years later for antibody persistence and booster response using serum bactericidal assay with human complement (hSBA).


METHODS
Children 7-10 and 11-15 years of age, who received MenACWY-CRM in the original study, and age-matched vaccine-naïve children, were enrolled in this extension study. After an initial blood draw, children received one dose of MenACWY-CRM as booster or primary dose, with a second blood draw 28 days later.


RESULTS
hSBA titers decreased five years after primary vaccination, but were higher than in non-vaccinated controls against serogroups C, W and Y, with substantial proportions having titers ≥8: 7-22% for A, 32-57% for C, 74-83% for W, and 48-54% for Y. Previously-vaccinated children demonstrated booster responses to revaccination against all four serogroups. Responses to primary vaccination in vaccine-naïve controls were lower and similar to primary responses observed in the original study. All vaccinations were generally well tolerated, with no safety concern raised.


CONCLUSIONS
Approximately half the children vaccinated as 2-10 year-olds maintained protective antibodies against serogroups C, W and Y five years later, but fewer did against serogroup A. Declining titers five years after vaccination and robust booster responses suggest that five years may be an appropriate interval to revaccinate children, subject to epidemiology and delivery considerations.
Kentucky Pediatric and Adult Research, Bardstown, KY, USA. Electronic address: slblockmd@hotmail.com.
Stan L
SL
Block
J. Lewis Research Inc., Salt Lake City, UT, USA.
Shane
S
Christensen
Novartis Vaccines and Diagnostics, Inc., Cambridge, MA, USA.
Bikash
B
Verma
Novartis Vaccines and Diagnostics, Inc., Cambridge, MA, USA.
Fang
F
Xie
Novartis Pharma BV, Amsterdam, The Netherlands.
Pavitra
P
Keshavan
Novartis Vaccines and Diagnostics, Inc., Cambridge, MA, USA.
Peter M
PM
Dull
Novartis Pharma BV, Amsterdam, The Netherlands.
Igor
I
Smolenov
D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003165:Complement System Proteins / Q000276:immunology; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*; D065288:Serogroup; D058248:Serum Bactericidal Antibody Assay; D013997:Time Factors; D014611:Vaccination
D000907:Antibodies, Bacterial; C556088:MenACWY-CRM vaccine; D022401:Meningococcal Vaccines; D003165:Complement System Proteins
Antibody persistence; Booster vaccination; Childhood vaccination; Meningococcal vaccine; NCT01823536