Richard A Adegbola

Publications (2)57.06 Total impact

• Source

  Available from: Simonetta Viviani

  Article: Immunogenicity and safety of a meningococcal A conjugate vaccine in Africans.

  Samba O Sow, Brown J Okoko, Aldiouma Diallo, Simonetta Viviani, Ray Borrow, George Carlone, Milagritos Tapia, Adebayo K Akinsola, Pascal Arduin, Helen Findlow, [......], Julie Chaumont, Lionel Martellet, Fatoumata Diallo, Olubukola T Idoko, Yuxiao Tang, Brian D Plikaytis, Prasad S Kulkarni, Elisa Marchetti, F Marc LaForce, Marie-Pierre Preziosi
  [show abstract] [hide abstract]
  ABSTRACT: Group A meningococci are the source of major epidemics of meningitis in Africa. An affordable, highly immunogenic meningococcal A conjugate vaccine is needed. We conducted two studies in Africa to evaluate a new MenA conjugate vaccine (PsA-TT). In study A, 601 children, 12 to 23 months of age, were randomly assigned to receive PsA-TT, a quadrivalent polysaccharide reference vaccine (PsACWY), or a control vaccine (Haemophilus influenzae type b conjugate vaccine [Hib-TT]). Ten months later, these children underwent another round of randomization within each group to receive a full dose of PsA-TT, a one-fifth dose of PsACWY, or a full dose of Hib-TT, with 589 of the original participants receiving a booster dose. In study B, 900 subjects between 2 and 29 years of age were randomly assigned to receive PsA-TT or PsACWY. Safety and reactogenicity were evaluated, and immunogenicity was assessed by measuring the activity of group A serum bactericidal antibody (SBA) with rabbit complement and performing an IgG group A-specific enzyme-linked immunosorbent assay. In study A, 96.0% of the subjects in the PsA-TT group and 63.7% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline; in study B, 78.2% of the subjects in the PsA-TT group and 46.2% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline. The geometric mean SBA titers in the PsA-TT groups in studies A and B were greater by factors of 16 and 3, respectively, than they were in the PsACWY groups (P<0.001). In study A, the PsA-TT group had higher antibody titers at week 40 than the PsACWY group and had obvious immunologic memory after receiving a polysaccharide booster vaccine. Safety profiles were similar across vaccine groups, although PsA-TT recipients were more likely than PsACWY recipients to have tenderness and induration at the vaccination site. Adverse events were consistent with age-specific morbidity in the study areas; no serious vaccine-related adverse events were reported. The PsA-TT vaccine elicited a stronger response to group A antibody than the PsACWY vaccine. (Funded by the Meningitis Vaccine Project through a grant from the Bill and Melinda Gates Foundation; Controlled-Trials.com numbers, ISRCTN78147026 and ISRCTN87739946.).
  New England Journal of Medicine 06/2011; 364(24):2293-304. · 53.30 Impact Factor
• Source

  Available from: Olubukola Idoko

  Article: Prospects and challenges with introduction of a mono-valent meningococcal conjugate vaccine in Africa.

  Brown J Okoko, Olubukola T Idoko, Richard A Adegbola
  [show abstract] [hide abstract]
  ABSTRACT: Epidemic meningococcal meningitis is a priority disease for prevention and control in Africa. The current World Health Organization (WHO) approach to the control of meningitis epidemics is based on early detection of cases and emergency vaccination of the population at risk with meningococcal polysaccharide (PS) vaccines. But this is a tall order for the developing nations of Africa where experts operate from an ineffective health system. Although the widespread use of meningococal polysaccharide vaccines has had a major and much appreciated public health impact on the disease it has not prevented epidemics of this dreaded infection. The current partnership between WHO and the PATH aims to develop, evaluate and introduce an appropriate and affordable meningococcal conjugate vaccine that could potentially provide for a means of preventing epidemic meningitis caused by N. meningitidis group A. In this paper, we review the prospects and challenges facing the introduction of the mono-valent conjugate vaccine in Africa.
  Vaccine 01/2009; 27(14):2023-9. · 3.77 Impact Factor