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After improving enrolment rates significantly, many developing countries such as Peru are facing the challenge to increase learning levels among students. Over the past few years, many researchers have turned to teacher-related variables as a way to better understand classroom processes that may help increase learning levels among students. In this study we analyze one of these, that falls under what Shulman (1986) called Pedagogical Content Knowledge (PCK). Specifically, in this study we analyze one of the areas of PCK which is knowledge of content and students. This was measured through a test where teachers were asked to explain students' mistakes and predict responses in similar mathematics exercises. We explore if PCK is associated with the socioeconomic status of children and if it has an effect on children's achievement. Additionally we analyze which teacher characteristics are associated with higher scores in PCK. The analysis uses the Young Lives longitudinal survey for Peru. We found that students´ socioeconomic status at age one and maternal education were positively associated with their teachers´ PCK by the time students were enrolled in fourth grade, thus depicting a very unequal education system. Furthermore, teachers' PCK was positively associated with student achievement, but only when a threshold for the PCK test was established. For our sample, male teachers, who were younger, and Spanish -speakers had higher PCK scores.

Several studies in developing countries have found that children who experience growth faltering in the first years of life show lower cognitive abilities than their peers. In this study, we use the Young Lives longitudinal dataset in Peru to analyze if attending pre-school affects cognitive abilities at age five years, and if there is an interaction with HAZ at age one year. Using instrumental variables we found, for receptive vocabulary, a positive effect of attending Jardines (formal) pre-schools; the effect of attending PRONOEI (community-based) pre-schools was not significant. More years attending Jardines was more beneficial for children who were better nourished. We suggest working to improve the quality of PRONOEIs, and with teachers on targeting children of lower nutritional status.

Introduction The Ebola virus disease (EVD) outbreak in 2014–2016 in West Africa was the largest on record and provided an opportunity for large clinical trials and accelerated efforts to develop an effective and safe preventative vaccine. Multiple questions regarding the safety, immunogenicity, and efficacy of EVD vaccines remain unanswered. To address these gaps in the evidence base, the Partnership for Research on Ebola Vaccines (PREVAC) trial was designed. This paper describes the design, methods, and baseline results of the PREVAC trial and discusses challenges that led to different protocol amendments. Methods This is a randomized, double-blind, placebo-controlled phase 2 clinical trial of three vaccine strategies against the Ebola virus in healthy volunteers 1 year of age and above. The three vaccine strategies being studied are the rVSVΔG-ZEBOV-GP vaccine, with and without a booster dose at 56 days, and the Ad26.ZEBOV,MVA-FN-Filo vaccine regimen with Ad26.ZEBOV given as the first dose and the MVA-FN-Filo vaccination given 56 days later. There have been 4 versions of the protocol with those enrolled in Version 4.0 comprising the primary analysis cohort. The primary endpoint is based on the antibody titer against the Ebola virus surface glycoprotein measured 12 months following the final injection. Results From April 2017 to December 2018, a total of 5002 volunteers were screened and 4789 enrolled. Participants were enrolled at 6 sites in four countries (Guinea, Liberia, Sierra Leone, and Mali). Of the 4789 participants, 2560 (53%) were adults and 2229 (47%) were children. Those < 18 years of age included 549 (12%) aged 1 to 4 years, 750 (16%) 5 to 11 years, and 930 (19%) aged 12–17 years. At baseline, the median (25th, 75th percentile) antibody titer to Ebola virus glycoprotein for 1090 participants was 72 (50, 116) EU/mL. Discussion The PREVAC trial is evaluating—placebo-controlled—two promising Ebola candidate vaccines in advanced stages of development. The results will address unanswered questions related to short- and long-term safety and immunogenicity for three vaccine strategies in adults and children. Trial registration ClinicalTrials.gov NCT02876328. Registered on 23 August 2016.

School composition is a topic that has gained increasing attention from researchers over the past few years, as it has been found that the socioeconomic characteristics of students are associated with their achievement. However, most research has been cross-sectional and carried out in industrialized countries. In this study we use parental education as a measure of classroom composition across schools in Peru, and find that there are high levels of segregation, especially at the extremes of the distribution. Using longitudinal data from the Young Lives study, we find that classroom composition was positively associated with achievement in mathematics and sense of belonging of students, and not associated with reading achievement or perception of security at school. We discuss these results and suggest that school composition is a relevant variable to include in descriptions of national educational systems in Latin America and as a context variable for results of achievement among students.