Meningococcal antibody persists 5 years after fourth dose of Hib/Men CY conjugate vaccine

SAN DIEGO — Protective antibody levels persisted in most children 5 years after the fourth dose of a Haemophilus influenzae type b and Neisseria meningitidis serogroups C and Y tetanus toxoid conjugate vaccine, according to data presented here during ID Week 2012.

Gary S. Marshall

Results of previous studies of the vaccine against Hib andN.meningitidis serogroups C and Y (HibMenCY-TT; MenHibrix, GlaxoSmithKline) indicated that protective antibodies persisted at least 3 years. The goal of this study, according to lead investigator Gary S. Marshall, MD, was to determine whether protective antibodies to Hib and MenC and MenY persisted 5 years after a fourth consecutive dose, as well as after a single dose given at 12 to 15 months of age in children who were primed with a standard Hib vaccine.

“The bottom line is that 5 years out from this series of immunizations, protective antibodies persisted against Hib and meningococcal serogroups C and Y in a majority of the vaccinees,” Marshall told Infectious Diseases in Children.

Participants received three doses of HibMenCY-TT or Hib-TT at ages 2, 4 and 6 months. At 12 to 15 months, those primed with HibMenCY-TT received a fourth dose of the same vaccine (HibMenCY-TTx4 group), and the patients primed with Hib-TT received a fourth dose of either the same vaccine (Hib-TTx4 group) or HibMenCY-TT (HibMenCYx1 group).

At the 5-year mark post-vaccination, blood samples from available children were tested for antibody persistence. For Hib, the endpoint was anti-polyribosylribitol phosphate (anti-PRP) concentration of at least 0.15 mcg/mL. For MenC and MenY, the primary endpoint was a serum bactericidal assay with human complement (hSBA) titer of at least 1:8.

Marshall, of the department of pediatrics at the University of Louisville School of Medicine, reported that 98.8% of children in the HibMenCY-TTx4 group had anti-PRP levels ≥0.15 mcg/mL, followed by 92.3% for the Hib-TTx4 group and 97.3% for the HibMenCYx1 group.

As for hSBA-MenC levels 1:8 or greater, 82.9% of children in the HibMenCY-TTx4 and 73.5% in the HibMenCYx1 group reached those levels vs. 21.1% in the control group.

A total of 69.5% of children in the HibMenCY-TTx4 group and 54.3% in the HibMenCYx1 group reached hSBA-MenY levels of 1:8 or greater vs. 18.4% in the control group.

“If we are going to use a meningococcal vaccine in infancy, we are going to want protection to last at least until 11-12 years of age, which is when meningococcal vaccine is now routinely given,” Marshall said. “Although the incidence of disease goes down between ages 2 and 10 years, this is reassurance that children who get a primary series of MenHibrix and then a booster at 12 months will have protective antibody for many years.”

No serious adverse events related to the vaccine were reported.

IDWeek 2012 is the first joint meeting of the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, the Society for Healthcare Epidemiologists of America, and the HIV Medical Association.

For more information:

Marshall G. Abstract #379. Presented at: ID Week 2012; Oct. 17-21, 2012; San Diego.

Gary S. Marshall, MD, can be reached at gary.marshall@louisville.edu.

Disclosure: The study was funded by GlaxoSmithKline (GSK) Biologicals. Marshall serves as a consultant, an investigator on clinical trials, and a scientific adviser for GSK and also has received speaker honoraria from GSK.