Carbopol improves the early cellular immune responses induced by the modified-life vaccine Ingelvac PRRS® MLV.

Adjuvants enhance both the magnitude and duration of immune responses, therefore representing a central component of vaccines. The nature of the adjuvant can determine the particular type of immune response, which may be skewed toward cytotoxic T cell (CTL) responses, antibody responses, or particular classes of T helper (Th) responses and antibody isotypes. Traditionally, adjuvants have been added to intrinsically poor immunogenic vaccines, such as those using whole killed organisms or subunit vaccines. Here, we have compared cellular immune responses induced by the immunogenic modified life-attenuated vaccine Ingelvac PRRS® MLV when administered alone or in combination with carbopol, a widely used adjuvant in veterinary medicine. Using functional readouts (IFN-γ ELISpot and cell proliferation) and analyzing phenotypical hallmarks of CD4T cell differentiation, we show that carbopol improves cellular immunity by inducing early IFN-γ-producing cells and by preferentially driving T cell differentiation to effector phenotypes. Our data suggest that adjuvants may enhance and modulate life-attenuated--not only subunit/inactivated--vaccines.

Predictive validity of a preschool neurodevelopmental instrument.

The Pediatric Examination of Educational Readiness (PEER) is a combined neurodevelopmental, behavioral, and health assessment for children ages 4 to 6 years old. The purpose of this study was to examine its predictive validity. One hundred seven five-year-olds received the PEER at age five. At age eight, all took the Iowa Tests of Basic Skills (ITBS), a nationally normed achievement battery. Mean ITBS scores were significantly different between those passing and failing the PEER Developmental Attainment section (t = 4.5, df = 105, p less than .001). Of six developmental areas sampled, preacademic skills emerged as the most potent predictor of achievement (R = .43, Re = .18, p less than .001). Neuromaturation scores did not correlate with ITBS results. Sensitivity of the PEER was 45%, specificity was 87% and test accuracy was 79%. We conclude that the PEER is useful in describing current developmental strengths and weaknesses but has limited ability in predicting future learning problems for individual children.

The validity of continuing developmental follow-up of high-risk infants to age 5 years.

We conducted a study to determine whether performance on developmental tests at age 5 years could predict academic achievement at age 8 years. As part of a longitudinal developmental surveillance project, 179 children at risk due to perinatal complications who had passed developmental screening through age 2 1/2 years and 50 comparison children underwent an extensive prekindergarten psychoeducational test battery at age 5 years and took the Iowa Tests of Basic Skills at age 8 years, if they had reached the third grade. The mean Iowa Tests of Basic Skills score was significantly lower for those children who were "flagged" on the prekindergarten psychoeducational test battery (t = 5.39). Preacademic, rather than developmental, items appeared to be the best predictors. However, the prekindergarten psychoeducational test battery correctly predicted low achievement or grade retention in only 58% of cases. Its sensitivity was 0.45 and its specificity was 0.85. No significant difference was noted between group Iowa Tests of Basic Skills mean scores for the high-risk or comparison group. When low achievement and failure to reach the third grade were combined, prevalence of "failure" was higher for the high-risk group (31% vs 24%). The only perinatal variable predictive of low achievement was neonatal seizures. In summary, because the ability to predict future academic achievement at age 5 years is limited, routine developmental testing for symptom-free preschool children is not warranted. High-risk infant follow-up programs should focus on the first several years of life.

Examining high-risk children for learning problems in the health care setting.

The validity of the Pediatric Evaluation of Educational Readiness (PEER) in evaluating high-risk 5-year-old children who passed developmental screenings through age 30 months was assessed by comparing it with a battery of standardized psychoeducational tests. High-risk children who "failed" the PEER scored significantly below those who "passed" the PEER on tests of verbal, perceptual-motor, and preacademic skills. Furthermore, scores on the PEER of the high-risk group were significantly below those of a normal comparison group. When the standardized test battery was used as the true indicator of developmental concerns, the sensitivity of the PEER averaged 0.60; specificity averaged 0.88. The overall hit rate was 78%. False-positive rate was 27%, the false-negative rate, 20%. Observations of behavior, including attention and activity, correlated at the .63 level (P less than .001) with those made independently by a psychometrist. The correlation of these observations to ratings of behavior by parents on the Child Behavior Checklist was .32 (P less than .001). It is concluded that the PEER distinguishes between groups of children at risk and not at risk for learning problems; however, in individual cases, the PEER and the standardized test agreed that a child had problems only 60% of the time. Thus two out of five children who may have problems would be missed by the PEER. The observations of behavior feature of the PEER seemed to be a reliable measure and to have some relationship to concerns indicated by parents.(ABSTRACT TRUNCATED AT 250 WORDS)