Distribution of aluminum in hair of Brazilian infants and correlation to aluminum-adjuvanted vaccine exposure.

BACKGROUND: Nursing children are exposed to dietary aluminum (in breast milk and/or infant formulas) and through aluminum-adjuvanted vaccines (AAVs). We studied total hair-Al concentrations of nursing children that had been immunized with hepatitis B, DTP, and meningococcal vaccines. METHODS: We studied the hair of 37 young children (aged 26 to 824 days) who were exposed to cumulative doses of Al ranging from 0.63 to 6.88 mg from AAVs. Graphite furnace atomic absorption spectrometry was used to reliably measure total Al concentrations in hair samples. RESULTS: The analytical method proved sensitive enough to quantify Al in the hair of nursing children. At current levels of exposure it is possible to determine total Al in hair sample of 1.65 mg. Cumulative doses of AAV in children ranged from 0.63 to 6.88 mg Al. Median hair-Al was 47.7 µg g⁻¹ (ranging from 12.2 to 221.9 µg g⁻¹). There was no statistically significant correlation between hair-Al concentration and age of child (r=-0.049; p=0.774), total exposure from vaccine (r=-0.078; p=0.643), or the time elapsed after the last AAVs (r=0.015; p=0.931). CONCLUSION: Aluminum in children's hair can be reliably measured but we are still uncertain how representative it can be of the Al body burden.

Principal component analysis and discrimination of variables associated with pre- and post-natal exposure to mercury.

The variance of variables associated with neurodevelopment at 180 days, pre-natal variables (Hg in placenta, blood and hair) and post-natal Hg exposure (including Thimerosal-containing vaccines, TCV) were examined in 82 exclusively breastfed infants using principal component analysis (PCA). This multivariate method was applied to identify hierarchy and sets of interrelated variables. The PCA yielded a two-factor solution, explaining 92% of variance and summarizing most of the relevant information in the dataset matrix: the first component represented birth weight and vaccine (first doses of Hepatitis B and DTP) variability and explained 57% of variance; the second component represented a gradient of neurodevelopment (Gesell scores) and explained 35% of variance. The third component explained only 3% of the remaining 8% variance. Beside CNS priming by breastfeeding, infant development (birth weight) and time of immunization with TCV should be considered in epidemiological studies. PCA can classify sets of variables related to vaccination and neuromotor development schedules, clearly discriminating between earlier and later TCV exposures of exclusively breastfed infants. In conclusion, the incommensurable concept of the chance of toxic risk caused by TCV-EtHg exposure against the proven benefit of immunization is in no way disputed here. However, infant neurodevelopmental (ND) disorders linked to Thimerosal-Hg stands in need of proof, but PCA points to the possibility of identifying exposure risk variables associated with ND schedules.

Evaluación y mejoramiento del aspecto físico de las vacunas pertussis y DPT elaboradas en el Instituto Nacional de Higiene "Rafael Rangel" / Improvement and evaluation of physical appearance of the pertussis vaccines and DPT elaborates in the Instituto Nacional de Higiene \"Rafael Rangel\"

Se evaluaron los procesos de recuperación de la vacuna pertussis y formulación de la vacuna DPT, elaborados en el Instituto Nacional de Higiene "Rafael Rangel", con el fin de mejorar el aspecto físico u homogeneidad de la vacuna pertussis antes de ser incorporada como fracción en la vacuna DPT. Se evaluaron la calidad del agua, concentración del adyuvante y la concentración y tiempo de almacenamiento de la vacuna pertussis. Se demostró que cuando fueron mezclados lotes de vacunas pertussis de baja concentración (menor de 200 Uop/ml), los cuales habían sido almacenados durante un período menor de dos años y habían sido previamente agitados, con calidad inyectable y a una concentración del adyuvante de 0,52 mg/dosis, generaron una vacuna DPT homogénea, comparable con otras vacunas similares producidas por laboratorios de reconocida trayectoria. Vacunas pertussis concentradas a valores superiores, generaron una vacuna DPT con presencia de aglomerados consistentes de la bacteria Bordetella pertussis. El incremento de la concentración del adyuvante en la vacuna DPT, hasta valores permisibles por la Organización Mundial de la Salud (1,25 mg/dosis) y el uso de agua de calidad inyectable mejoran el aspecto físico de la vacuna DPT. La visualización macroscópica y microscópica de las vacunas

Empleo de la inmunodifusión radial simple en la evaluación de vacuna DPT de producción nacional / I use of the simple radial inmunodifussión in the evaluation of bovine DPT of national production

Se describe el método de obtención de la vacuna DPT, desarrollada por primera vez en Cuba, y se expresan los resultados de las pruebas químicas y biológicas realizadas a 7 lotes de vacuna final. Se comprueba la eficiencia de la técnica de inmunodifusión radial simple para la prueba de identidad, y se compara con la prueba de floculación para la determinación de las concentraciones de los toxoides diftéricos y tetánicos presentes en la vacuna(AU)