Immunogenicity, safety, and memory of different schedules of Neisseria meningitidis A/C-diphtheria toxoid conjugate vaccine in infants in Niger.

We studied one to four doses of meningococcal polysaccharides A and C conjugated to diphtheria toxoid (Men D) versus A/C polysaccharide (Men PS) vaccine in 618 infants in Niger. Men PS at 24 months permitted evaluating memory. Two Men D doses (at 3 and 9 months) induced higher serum bactericidal activity (SBA) than other regimens. SBA titers after Men PS at 24 months were higher in those given Men D in infancy versus Men PS. While responses were lower for serogroup C, hyporesponsiveness was not evident. Men D was well-tolerated. A single Men D dose in infancy appeared to induce memory.

[Epidemiology of snake envenomations in northern Cameroon]. / Epidémiologie des envenimations ophidiennes dans le nord du Cameroun.

Epidemiological surveys concerning snakebites were carried out in the savannah area of North Cameroon according to two methods. A retrospective survey carried out in 5 hospitals or dispensaries covering a 3- to 8-year period according to locality was followed by a prospective survey in 4 of these health centres lasting 1 or 2 years according to location. These studies involved respectively 1,710 and 359 patients. The annual incidence varied between 50 and 250 envenomations per 100,000 inhabitants according to year and locality. The average annual incidence was close to 200 cases. Echis ocellatus corresponded to 85% of the identified snakebites. Lethality ranged from 0 to 23.9% of the envenomations. It significantly decreased during the prospective study due to the systematic use of antivenoms administered through the venous route (IPSER Africa then FAV Afrique). During the prospective study, we observed that 25% of snakebite victims did not present any symptoms: 71% presented an oedema, 63% a coagulopathy and less than 5% a necrosis. The population at risk involved people aged 15 to 44 years, especially males. Most of the bites had occurred during agricultural activity. In the cotton zone, more than 40% of the envenomations took place during the 3 months of the field preparation and cotton sowing. Elsewhere, the snakebites were spread out over time with a clear increase during the rain season.

Safety and immunogenicity of TETRActHIB (a vaccine combining DTP vaccine and Haemophilus influenzae type B conjugate vaccine) administered to infants at 6, 10 and 14 weeks of age.

The safety and immunogenicity of TETRActHIB (a vaccine combining diphtheria and tetanus toxoids-pertussis vaccine (DTP) with Haemophilus influenzae type b (Hib) conjugate vaccine (polyribosyl ribitol phosphate conjugated to tetanus protein) (PRP-T)) was assessed in 131 Cape Town infants immunized at 6, 10 and 14 weeks of age. Serological responses to all component antigens were measured before the first dose and at 18 weeks of age. In addition, anti-PRP antibodies were measured at 9 and 18 months of age to determine long-term immunogenicity. The vaccine was well tolerated by infants and no significant side-effects were reported. Responses to Hib at 18 weeks of age were good in that most infants achieved a level of anti-PRP antibodies > or = 0.15 microgram/ml, indicative of short-term protection, and 70% achieved a level > or = 1 microgram/ml, indicative of long-term protection. The proportions of children with protective levels > or = 0.15 microgram/ml and > or = 1 microgram/ml were similar at 9 and 18 months of age, i.e. approximately 75% and 45%, respectively. Responses to tetanus and diphtheria toxoids were excellent and all infants achieved protective serological levels. Responses to pertussis were moderate in that approximately 65% achieved 'protective' serum levels of pertussis agglutinins, i.e. titres > or = 320. In conclusion, this study has shown that the DTP/PRP-T vaccine is safe, immunogenic and well tolerated in infants immunised at 6, 10 and 14 weeks of age. TETRActHIB is therefore suitable for inclusion in the World Health Organisation Expanded Programme on Immunisation (WHO EPI) schedule.