Measles Vaccination in HIV-Infected Children: Systematic Review and Meta-Analysis of Safety and Immunogenicity

Background. Measles control may be more challenging in regions with a high prevalence of HIV infection. HIV-infected children are likely to derive particular benefit from measles vaccines because of an increased risk of severe illness. However, HIV infection can impair vaccine effectiveness and may increase the risk of serious adverse events after receipt of live vaccines. We conducted a systematic review to assess the safety and immunogenicity of measles vaccine in HIV-infected children. Methods. The authors searched 8 databases through 12 February 2009 and reference lists. Study selection and data extraction were conducted in duplicate. Meta-analysis was conducted when appropriate. Results. Thirty-nine studies published from 1987 through 2008 were included. In 19 studies with information about measles vaccine safety, more than half reported no serious adverse events. Among HIV-infected children, 59% (95% confidence intervals [CI], 46-71%) were seropositive after receiving standard-titer measles vaccine at 6 months (1 study), comparable to the proportion of seropositive HIV-infected children vaccinated at 9 (8 studies) and 12 months (10 studies). Among HIV-exposed but uninfected and HIV-unexposed children, the proportion of seropositive children increased with increasing age at vaccination. Fewer HIV-infected children were protected after vaccination at 12 months than HIV-exposed but uninfected children (relative risk, 0.61; 95% CI, .50-.73). Conclusions. Measles vaccines appear to be safe in HIV-infected children, but the evidence is limited. When the burden of measles is high, measles vaccination at 6 months of age is likely to benefit children of HIV-infected women, regardless of the child's HIV infection statu

A literature review and survey of childhood pneumonia etiology studies: 2000-2010.

The Pneumonia Etiology Research for Child Health (PERCH) project is the largest multicountry etiology study of childhood pneumonia since the Board on Science and Technology in International Development studies of the 1980s. However, it is not the only recent or ongoing pneumonia etiology study, and even with seven sites, it cannot capture all epidemiologic settings in the developing world. Funding providers, researchers and policymakers rely on the best available evidence to strategically plan programs, new research directions and interventions. We aimed to describe the current landscape of recent pneumonia etiology studies in children under 5 years of age in the developed and developing world, as ascertained by a literature review of relevant studies with data since the year 2000 and a survey of researchers in the field of childhood pneumonia. We collected information on the study population, study design, case definitions, laboratory samples and methods and identified pathogens. A literature review identified 88 studies with child pneumonia etiology results. As of June 2010, our survey of researchers identified an additional 65 ongoing and recently completed child pneumonia etiology studies. This demonstrates the broad existing context into which the PERCH study must be placed. However, the landscape analysis also reveals a multiplicity of case definitions, levels of clinician involvement, facility types, specimen collection, and laboratory techniques. It reinforces the need for the standardization of methods and analyses for present and future pneumonia etiology studies in order to optimize their cumulative potential to accurately describe the microbial causes of childhood pneumonia

Measles vaccination in HIV-infected children: systematic review and meta-analysis of safety and immunogenicity

Background. Measles control may be more challenging in regions with a high prevalence of HIV infection. HIV-infected children are likely to derive particular benefit from measles vaccines because of an increased risk of severe illness. However, HIV infection can impair vaccine effectiveness and may increase the risk of serious adverse events after receipt of live vaccines. We conducted a systematic review to assess the safety and immunogenicity of measles vaccine in HIV-infected children. Methods. The authors searched 8 databases through 12 February 2009 and reference lists. Study selection and data extraction were conducted in duplicate. Meta-analysis was conducted when appropriate. Results. Thirty-nine studies published from 1987 through 2008 were included. In 19 studies with information about measles vaccine safety, more than half reported no serious adverse events. Among HIV-infected children, 59% (95% confidence intervals [CI], 46–71%) were seropositive after receiving standard-titer measles vaccine at 6 months (1 study), comparable to the proportion of seropositive HIV-infected children vaccinated at 9 (8 studies) and 12 months (10 studies). Among HIV-exposed but uninfected and HIV-unexposed children, the proportion of seropositive children increased with increasing age at vaccination. Fewer HIV-infected children were protected after vaccination at 12 months than HIV-exposed but uninfected children (relative risk, 0.61; 95% CI, .50–.73). Conclusions. Measles vaccines appear to be safe in HIV-infected children, but the evidence is limited. When the burden of measles is high, measles vaccination at 6 months of age is likely to benefit children of HIV-infected women, regardless of the child's HIV infection status

Standardizing surveillance of pneumococcal disease.

BACKGROUND: Surveillance for invasive pneumococcal disease has been conducted using a variety of case ascertainment methods and diagnostic tools. Interstudy differences in observed rates of invasive pneumococcal disease could reflect variations in surveillance methods or true epidemiological differences in disease incidence. To facilitate comparisons of surveillance data among countries, investigators of Pneumococcal Vaccines Accelerated Development and Introduction Plan-sponsored projects have developed standard case definitions and data reporting methods. METHODS: Investigators developed case definitions for meningitis, pneumonia, and very severe disease using existing World Health Organization guidelines and clinical definitions from Africa and Asia. Standardized case definitions were used to standardize reporting of aggregated results. Univariate analyses were conducted to compare results among countries and to identify factors contributing to detection of Streptococcus pneumoniae. RESULTS: Surveillance sites varied with regard to the age groups targeted, disease syndromes monitored, specimens collected, and laboratory methods employed. The proportion of specimens positive for pneumococcus was greater for cerebrospinal fluid specimens (1.2%-19.4%) than for blood specimens (0.1%-1.4%) in all countries (range, 1.3-38-fold greater). The distribution of disease syndromes and pneumonia severity captured by surveillance differed among countries. The proportion of disease cases with pneumococcus detected varied by syndrome (meningitis, 1.4%-10.8%; pneumonia, 0.2%-1.3%; other, 0.2%-1.2%) and illness severity (nonsevere pneumonia, 0%-2.7%; severe pneumonia, 0.2%-1.2%), although these variations were not consistent for all sites. Antigen testing and polymerase chain reaction increased the proportion of cerebrospinal fluid specimens with pneumococcus identified by 1.3-5.5-fold, compared with culture alone. CONCLUSIONS: Standardized case definitions and data reporting enhanced our understanding of pneumococcal epidemiology and enabled us to assess the contributions of specimen type, disease syndrome, pneumonia severity, and diagnostic tools to rate of pneumococcal detection. Broader standardization and more-detailed data reporting would further improve interpretation of surveillance results