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J L Excler

Publications and source records attributed to J L Excler.

46 records · Page 3Linked to original sources
PubMedDate not supplied

Potentials and limitations of protein vaccines in infants.

Immunization of infants represents a difficult challenge since immune responses in infants differ qualitatively from those of adults (immature immune and bias towards Th2 rather than a Th1 immune responses). While protein vaccines are immunogenic in infants earlier than polysaccharides in the very first months of life, requiring repeated administration. Protein vaccines such as diphtheria and tetanus toxoids and hepatitis B antigens are safe and immunogenic in infants, able to induce long-lasting memory, and effective. HB vaccines are the first vaccines administered at birth against a sexually transmitted disease and that prevent cancer. These success stories must however be tempered by the existence of immunologic interferences that may occur when combining vaccines in a single injection. Moreover, very little is known whether inappropriate protein conformation and glycosylation play roles in the impairment of the functional immunogenicity of protein vaccines in infants. Although much is known about how to produce and purify proteins, we know much less about how protein characteristics are related to functional immunogenicity.

Bacterial Proteins↗
PubMedDate not supplied

Human immunodeficiency virus vaccine development in developing countries: are efficacy trials feasible?

The implementation of human immunodeficiency virus (HIV) vaccine efficacy trials in developing countries represents an unprecedented series of challenges for the medical and scientific communities, health authorities, policy makers, and the populations of diverse countries. Such trials require great attention, dedication, and information at the earliest possible time from many groups in these communities, as well as the clear and full collaboration of all the national and international institutions and agencies involved. This article discusses suggestions and makes recommendations regarding multiple hurdles to trial implementation, including access to appropriate populations, incidence and natural history of HRV type 1 (HIV-1) infection, definition of efficacy endpoints, and logistical, ethical, regulatory, political, and media issues. The conduct of phase I and II trials in developing countries will be a critical step for appropriate vaccine selection and in helping to identify the country- and community-specific issues and the needs for further implementation. Some countries have already established their own national HIV vaccine development plans. Additional operational and action plans with special emphasis on efficacy trial implementation would be strongly recommended after country-specific preparedness workshops and constitution of national or regional task forces.

AIDS Vaccines↗
PubMedDate not supplied

[Breast feeding and birth spacing in Burundi: an approach].

Breast-feeding (BFD), post-partum amenorrhea (PPA), and birth interval (BI) were studied in 247 mothers from Burundi (159 rural and 88 urban). BFD was higher in rural than in urban areas (23.8 +/- 6.8 vs 16.5 +/- 7.2 mths, p less than 0.001), as for PPA (16.9 +/- 8.5 vs 8.9 +/- 8 mths, p less than 0.001) and Bl (29 +/- 11 vs 25.7 +/- 10.7 mths, p less than 0.01). PPA of non exclusively breast-feeding (NEB) mothers was lower than that of the other mothers (5.7 +/- 6.5 vs 13.9 +/- 9 mths, p less than 0.001). The proportion of mothers with PPA less than or equal to 12 months was higher in NEB mothers (88.9% vs 49%, p less than 0.001). The relative risk of pregnancy 9 to 12 mths after a birth was 4 times higher for these mothers (28% vs 9%, RR = 3.9, p less than 0.001). PPA and BI were correlated with BFD (respectively r = 0.644 and r = 0.21, p less than 0.001). A multivariate analysis showed that PPA is lowered when BFD and frequency of sucking are reduced in urban high socio-economic levels (R = 56%, p less than 0.01). BI was not so lowered in urban area than expected with a lower BFD and PPA. These data suggest that post-partum infertility period lowered in urban area would be partially counterbalanced by cultural taboo inhibiting sexual intercourse during breast-feeding. Deep modification in sexual behavior accelerated by use of contraceptives should lead to be careful in their spread in family planning programmes where breast-feeding promotion is more than ever a priority.

Adult↗
PubMedDate not supplied

[Protein-energy malnutrition in an urban African milieu (Togo). Etiologic factors in kwashiorkor and marasmus-kwashiorkor].

The etiologic factors of protein-energy malnutrition (P.E.M.) have been studied in 59 children with kwashiorkor (KWK) or marasmus-kwashiorkor (MKWK) and living in an african urban area. The decline of breast feeding leads to an earlier P.E.M., mainly MKWK. This decline is linked to urbanization, mother's activities, dislocation of traditional structures and use of artificial formulas. Essentially based on cereals, the diet is responsible of the post-weaning P.E.M. Poverty, ignorance and food taboos are related to a lack in weaning food varieties. A small number of infants with KWK had a rich protein diet putting back the cause of an hypoproteic diet on the KWK onset. Infections play a determinant role in the onset of KWK and of some MKWK, after 2 years of age. Diarrhoea, measles, bronchopulmonary and parasitic diseases are the most prevalent infections. Among socio-cultural factors, conjugal disorders are predominating with child-mother break-up and father's bonding failure. At the opposite of rural areas, the family size is reduced. The three first birth ranges are specially concerned with young inexperienced mothers.

Breast Feeding↗
PubMedDate not supplied

[Pneumocystis carinii pneumonia in children. Apropos of 33 cases].

From 1964 to 1983, thirty-three children have developed Pneumocystis carinii pneumonia (18 boys and 15 girls). The affection appears before 1 year of age in 73% of the cases (mean +/- SD: 6,12 +/- 4,6 months). The predisposing factors for the disease include hypotrophy (7), immune deficiency (26: 79%) (12 congenital and 14 acquired). The thymodependant lymphocytic system is concerned in 15 cases (46%) with only 5 neoplasic origins. The onset of the disease is in the first year of immuno-suppresive treatment in 71% of the cases. It is acute in 27% of the cases. Polypnea is found in 94% of the cases, cyanosis 73%, fever 70%, respiratory distress 64%. Distal endobronchial brushing associated with distal bronchopulmonary lavage and surgical pulmonary biopsy seem the best methods of direct positive diagnosis. The specific serology is less useful. Among the 20 treated children, 7 were cured (35%). The global mortality rate is still high (79%). The new proposed therapeutic schema includes either pentamidine as a "starter" effect (4 mg/kg/d IM/ X 5 d) associated with pyrimetamine-sulfadoxine (1,25 mg PYR/25 mg SUL/kg/d every 8 days) or trimethoprim-sulfamethoxazole (20 mg TMP/100 mg SMZ/kg/d X 14 d; efficient plasmatic TMP: 5 to 10 micrograms/ml). Chemoprophylaxy must be followed by all "high risk" patients during the totality of the immunosuppressive period (PYR-SUL every 15 days associated with folinic acid).

Child↗
PubMedDate not supplied

[Flubendazole in human Echinococcus granulosus hydatidosis. Preoperative care: parasit-pharmacologic study].

The effect of flubendazole in human hydatic disease due to E. granulosus has been studied in 22 patients with one or several hydatic cysts of different sites. Flubendazole has been given orally before surgery for a 10 days mean period, at 4 g daily in adults and 1 g daily in children. Flubendazole has been titrated by radioimmuno-assay in sera, urines and bile taken 12 to 24 hours after the last ingestion and in the hydatic cyst (membranes and liquid). The scolex vitality was determined by direct optic microscopy and by intra-peritoneal mouse inoculation. Seven non-treated patients, without hydatic disease, were considered as controls. The flubendazole concentrations in sera (3.01 +/- 3.73 ng/ml) and in urines (7.6 +/- 7.5 ng ml) are low. They are also low in membranes (3.21 +/- ng/mg) and in hydatic liquid, but significantly more elevated in the hepatic localisation than in the pulmonary localisation. The bile concentrations are high (167.9 +/- 133.2 ng/ml). There is no correlation between these concentrations and the amounts of flubendazole administered. The scolex vitality was correlated neither with the amounts of flubendazole administered, nor with the concentrations of flubendazole in the hydatic cyst. Further studies are necessary before judging of the efficacy of flubendazole in the human hydatic disease.

Adolescent↗
PubMedDate not supplied

[Inclusion of hepatitis B vaccination in the Expanded Program of Immunization: feasibility study in the medical region of Kolda (Senegal)].

Hepatitis B is highly endemic in Senegal. The prevalence of hepatitis B antigens in the population was estimated to be 10 to 12% in 1982. According to the WHO recommendations, a hepatitis B vaccination program (HBV) was launched in 10 medical centers in the Kolda medical region to assess the feasibility of including HBV in the EPI. The epidemiological impact of HBV was also investigated by comparison of the vaccinated zone (VZ) to a control non vaccinated zone (NVZ). HBV coverage had a pattern similar to that of DPT-IPV, but at a lower level: the overall coverage with HBV was only 37.5%, and the drop out rate for HBV1-3 was only 34.4%. In addition, the coverage of the under one year age group was insufficient: 45% for HBV3 as compared to 78% for DPT3 (p < 0.0001). Routine vaccination records in the medical centers in the VZ were consistent with the findings of cluster surveys. Hepatitis B markers were less prevalent among vaccinated that non vaccinated children (8 versus 18.5%, p < 0.001). HB antigenemia was significantly less frequent in the VZ than the NVZ (3.9 versus 10.9, p < 0.0001), and the difference was even larger for all hepatitis markers (7.4 versus 23.7%, p < 0.0001). This study therefore suggests that the inclusion of HBV in the EPI should be continued and strengthened in less accessible regions by an adapted social mobilization program. HBV could then be extended to the whole medical district of Kolda in association with regular epidemiological and serological surveillance.

Child, Preschool↗
PubMedDate not supplied

[Control of hepatitis B in French Polynesia with a program of systematic vaccination of newborns with the Genhevac B vaccine].

In 1988, a 5-year vaccination program against hepatitis B was launched for all newborns in a pilot area, the Austral archipelago in French Polynesia. Genhevac B, a recombinant vaccine produced from mammalian cells was administered. Three different immunization schedules were used, none of them including additional specific immunoglobulin: i) four doses, one at each months (M) 0, 1, 2, and 12; ii) three doses one at each MO, M1 and M6; and iii) three doses one at each MO, M1 and M12. Each year during the 5 year period a serological survey was conducted. Of the 837 children who received at least one vaccine dose, 5 were HBsAg carriers. Seroprotection rates for anti-HBs and anti-PreS2 antibodies were 88% after one dose and 97% after two doses. After the third dose, seroprotection rates and geometric mean titers of anti-HBs antibodies were 95% and 217 mIU/ml for schedule (i) (three dose only); 92% and 389 mIU/ml for schedule (ii) and 93% and 344 mIU/ml for schedule (iii) respectively. After four doses (schedule i) the values were 100% and 1228 mIU/ml. Of the 18 newborns whose mothers were positive for both HBsAg and HBeAg, one was a HBsAg carrier. The estimated protective rate for prevention of perinatal transmission was 94%. This study suggests that in field conditions, systematic vaccination of newborns without using specific immunoglobulins can confer early protection. The schedule recommended for use in French Polynesia was three doses, at MO, M1 and M6-12 (between 6 and 12 months) with an additional booster dose at age 6 years, the last year of nursery school. Since April 1992, all children born in French Polynesia have been vaccinated according to this schedule. A catch-up program has been implemented for children aged 4 to 10 years old using a similar immunization schedule.

Child↗