Are the pneumococcal polysaccharide vaccines effective? Meta-analysis of the prospective trials

The objective was to review the evidence of effectiveness of the polyvalent polysaccharide pneumococcal vaccine from prospective properly randomised controlled trials comparing pneumococcal vaccines with placebo in subjects who are immunocompetent and those likely to have an impaired immune system. Databases searched included the Cochrane Library, (issue 2, 2000), MEDLINE (1966-August 2000), PubMed (to August 2000) and EMBASE ( to August 2000). Reference lists of reports and reviews were also searched. To be included in the analysis, a study had to have been a prospective randomised comparison of a polysaccharide pneumococcal vaccine (any valency) and to have a placebo or no treatment comparison group. Papers had to report important clinical outcomes, such as rates of pneumonia, pneumococcal pneumonia, lower respiratory tract infections, pneumonia deaths or bacteraemia. Serological outcomes were not sought. Thirteen randomised comparisons with over 45,000 subjects were identified in an extensive literature review. Eight studies had a quality score of 3 or more on a scale of 1 to 5. In three comparisons with 21,152 immunocompetent subjects (South African gold miners, New Guinea highlanders) pneumococcal vaccination was effective in reducing the incidence of all-cause pneumonia (relative risk 0.56, 95% confidence interval 0.47 to 0.66), pneumococcal pneumonia (0.16; 0.11 to 0.23), pneumonia deaths (0.70; 0.50 to 0.96) and bacteraemia (0.18; 0.09 to 0.34). In ten comparisons in over 24,000 people who were elderly or likely to have impaired immune systems, pneumococcal vaccination was without effect for any outcome. Present guidelines recommend pneumococcal vaccination for "high-risk" groups. There is no evidence from randomised trials that this is of any benefit

Tracing Changes in Families Who Participated in the Home-Start Parenting Program: Parental Sense of Competence as Mechanism of Change

The present study aimed to (1) determine the long-term effectiveness of Home-Start, a preventive parenting program, and (2) test the hypothesis that changes in maternal sense of competence mediate the program’s effects. Participants were 124 mothers (n = 66 intervention, n = 58 comparison). Four assessments took place during a 1-year period. Latent growth modeling showed that Home-Start enhanced growth in maternal sense of competence and supportive parenting, and led to a decrease in the use of inept discipline. Results of mediational and cross-lagged analyses were consistent with the hypothesized model: Participation in Home-Start was related to the changes in maternal sense of competence, which in turn predicted changes in parenting. The results affirm the importance of directly targeting parental sense of competence in the context of prevention work with parents

Assessing the sensitivity of modelled water partitioning to global precipitation datasets in a data-scarce dryland region

Precipitation is the primary driver of hydrological models, and its spatial and temporal variability have a great impact on water partitioning. However, in data-sparse regions, uncertainty in precipitation estimates is high and the sensitivity of water partitioning to this uncertainty is unknown. This is a particular challenge in drylands (semi-arid and arid regions) where the water balance is highly sensitive to rainfall, yet there is commonly a lack of in situ rain gauge data. To understand the impact of precipitation uncertainty on the water balance in drylands, here we have performed simulations with a process-based hydrological model developed to characterize the water balance in arid and semi-arid regions (DRYP: DRYland water Partitioning model). We performed a series of numerical analyses in the Upper Ewaso Ng'iro basin, Kenya driven by three gridded precipitation datasets with different spatio-temporal resolutions (IMERG, MSWEP, and ERA5), evaluating simulations against streamflow observations and remotely sensed data products of soil moisture, actual evapotranspiration, and total water storage. We found that despite the great differences in the spatial distribution of rainfall across a climatic gradient within the basin, DRYP shows good performance for representing streamflow (KGE >0.6), soil moisture, actual evapotranspiration, and total water storage (r >0.5). However, the choice of precipitation datasets greatly influences surface (infiltration, runoff, and transmission losses) and subsurface fluxes (groundwater recharge and discharge) across different climatic zones of the Ewaso Ng'iro basin. Within humid areas, evapotranspiration does not show sensitivity to the choice of precipitation dataset, however, in dry lowland areas it becomes more sensitive to precipitation rates as water-limited conditions develop. The analysis shows that the highest rates of precipitation produce high rates of diffuse recharge in Ewaso uplands and also propagate into runoff, transmission losses and, ultimately focused recharge, with the latter acting as the main mechanism of groundwater recharge in low dry areas. The results from this modelling exercise suggest that care must be taken in selecting forcing precipitation data to drive hydrological modelling efforts, especially in basins that span a climatic gradient. These results also suggest that more effort is required to reduce uncertainty between different precipitation datasets, which will in turn result in more consistent quantification of the water balance