Highlight of 2023: The metabolic symphony - orchestrating T-cell immunity.

The significance of metabolites in orchestrating immune cells is now recognized to be on par with other key immune modulators, such as cytokines or chemokines. Seminal discoveries have now been built upon with discoveries that have acted to take the discipline to new heights, particularly in T-cell immunity. This accelerated progress has uncovered a plethora of opportunities for pharmacological intervention, with the aim of harnessing immunometabolism for refined immune modulation across several pathologies. This Research Highlight focuses on the latest breakthroughs during 2023 from the preceding year that provide mechanistic insight, as well as viable translational opportunities, in the field of T-cell immunometabolism.

The Injury Prevention Program to Reduce Early Childhood Injuries: A Cluster Randomized Trial.

BACKGROUND AND OBJECTIVES: The American Academy of Pediatrics designed The Injury Prevention Program (TIPP) in 1983 to help pediatricians prevent unintentional injuries, but TIPP's effectiveness has never been formally evaluated. We sought to evaluate the impact of TIPP on reported injuries in the first 2 years of life. METHODS: We conducted a stratified, cluster-randomized trial at 4 academic medical centers: 2 centers trained their pediatric residents and implemented TIPP screening and counseling materials at all well-child checks (WCCs) for ages 2 to 24 months, and 2 centers implemented obesity prevention. At each WCC, parents reported the number of child injuries since the previous WCC. Proportional odds logistic regression analyses with generalized estimating equation examined the extent to which the number of injuries reported were reduced at TIPP intervention sites compared with control sites, adjusting for baseline child, parent, and household factors. RESULTS: A total of 781 parent-infant dyads (349 TIPP; 432 control) were enrolled and had sufficient data to qualify for analyses: 51% Hispanic, 28% non-Hispanic Black, and 87% insured by Medicaid. Those at TIPP sites had significant reduction in the adjusted odds of reported injuries compared with non-TIPP sites throughout the follow-up (P = .005), with adjusted odds ratios (95% CI) of 0.77 (0.66-0.91), 0.60 (0.44-0.82), 0.32 (0.16-0.62), 0.26 (0.12-0.53), and 0.27 (0.14-0.52) at 4, 6, 12, 18, and 24 months, respectively. CONCLUSIONS: In this cluster-randomized trial with predominantly low-income, Hispanic, and non-Hispanic Black families, TIPP resulted in a significant reduction in parent-reported injuries. Our study provides evidence for implementing the American Academy of Pediatrics' TIPP in routine well-child care.

Life-Threatening MOG Antibody-Associated Hemorrhagic ADEM With Elevated CSF IL-6.

Acute disseminated encephalomyelitis (ADEM) is one characteristic manifestation of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). A previously healthy man presented with retro-orbital headache and urinary retention 14 days after Tdap vaccination. Brain and spine MRI suggested a CNS demyelinating process. Despite treatment with IV steroids, he deteriorated, manifesting hemiparesis and later impaired consciousness, requiring intubation. A repeat brain MRI demonstrated new bilateral supratentorial lesions associated with venous sinus thrombosis, hemorrhage, and midline shift. Anti-MOG antibody was present at a high titer. CSF IL-6 protein was >2,000 times above the upper limits of normal. He improved after plasma exchange, then began monthly treatment alone with anti-IL-6 receptor antibody, tocilizumab, and has remained stable. This case highlights how adult-onset MOGAD, like childhood ADEM, can rapidly become life-threatening. The markedly elevated CSF IL-6 observed here supports consideration for evaluating CSF cytokines more broadly in patients with acute MOGAD.

Search for Antideuterons of Cosmic Origin Using the BESS-Polar II Magnetic-Rigidity Spectrometer.

We searched for antideuterons (d[over ¯]'s) in the 4.7×10^{9} cosmic-ray events observed during the BESS-Polar II flight at solar minimum in 2007-2008 but found no candidates. The resulting 95% C.L. upper limit on the d[over ¯] flux is 6.7×10^{-5} (m^{2} s sr GeV/n)^{-1} in an energy range from 0.163 to 1.100 GeV/n. The result has improved by more than a factor of 14 from the upper limit of BESS97, which had a potential comparable to that of BESS-Polar II in the search for cosmic-origin d[over ¯]'s and was conducted during the former solar minimum. The upper limit of d[over ¯] flux from BESS-Polar II is the first result achieving the sensitivity to constrain the latest theoretical predictions.

Unrecognized volatile and semi-volatile organic compounds from brake wear.

Motor vehicles are among the major sources of pollutants and greenhouse gases in urban areas and a transition to "zero emission vehicles" is underway worldwide. However, emissions associated with brake and tire wear will remain. We show here that previously unrecognized volatile and semi-volatile organic compounds, which have a similarity to biomass burning emissions are emitted during braking. These include greenhouse gases or, these classified as Hazardous Air Pollutants, as well as nitrogen-containing organics, nitrogen oxides and ammonia. The distribution and reactivity of these gaseous emissions are such that they can react in air to form ozone and other secondary pollutants with adverse health and climate consequences. Some of the compounds may prove to be unique markers of brake emissions. At higher temperatures, nucleation and growth of nanoparticles is also observed. Regions with high traffic, which are often disadvantaged communities, as well as commuters can be impacted by these emissions even after combustion-powered vehicles are phased out.

Outcomes of Hepatic Artery-Based Therapies and Systemic Multiagent Chemotherapy in Unresectable Colorectal Liver Metastases: A Systematic Review and Meta-analysis.

BACKGROUND: Treatment of unresectable colorectal liver metastases (UCRLM) includes locoregional and systemic therapy. A comprehensive analysis capturing long-term outcomes of these treatment options has not been performed. OBJECTIVE: A systematic review and meta-analysis was performed to calculate pooled outcomes of hepatic artery infusion with systemic chemotherapy (HAI-S), transarterial chemoembolization with systemic chemotherapy (TACE-S), transarterial radioembolization with systemic chemotherapy (TARE-S), doublet (FOLFOX, FOLFIRI), and triplet chemotherapy (FOLFOXIRI). METHODS: Outcomes included overall survival (OS), progression-free survival (PFS), rate of conversion to resection (CTR), and response rate (RR). RESULTS: A total of 32, 7, 9, and 14 publications were included in the HAI-S, TACE-S, and TARE-S chemotherapy arms. The 6/12/24/36-month OS estimates for HAI-S, TACE-S, TARE-S, FOLFOX, FOLFIRI, and FOLFOXIRI were 97%/80%/54%/35%, 100%/83%/40%/14%, 82%/61%/34%/21%, 96%/83%/53%/36%, and 96%/93%/72%/55%. Similarly, the 6/12/24/36-month PFS estimates were 74%/44%/19%/14%, 66%/20%/9%/3%, 57%/23%/10%/3%, 69%/30%/12%/7%, and 88%/55%/18%/11%. The corresponding CTR and RR rates were 31, 20%, unmeasurable (TARE-S), 35, 53; and 49, 45, 45, 50, 80%, respectively. The majority of chemotherapy studies included first-line therapy and liver-only metastases, whereas most HAI-S studies were pretreated. On subgroup analysis in first-line setting with liver-only metastases, the HAI-S arm had comparable outcomes to FOLFOXIRI and outperformed doublet chemotherapy regimens. Although triplet chemotherapy appeared to outperform other arms, high toxicity and inclusion of potentially resectable patients must be considered while interpreting results. CONCLUSIONS: HAI-S and multiagent chemotherapy are effective therapies for UCRLM. To make definitive conclusions, a randomized trial with comparable patient characteristics and line of therapy will be required. The upcoming EA2222 PUMP trial may help to address this question.

Factors influencing the willingness to pay a price premium for red meat with potential to improve consumer wellness in Australia and the United States of America.

This study determined consumers' attitudes towards physical and mental wellness related to red meat consumption and their willingness to pay (WTP) more for the meat. In 2019, two online surveys of red meat eaters were conducted in the USA (n = 1000) and Australia (n = 523) using commercial platforms. Results showed that over 90% of respondents indicated interest in purchasing red meat to improve their wellness status. Additionally, about 85% indicated their WTP more for red meat for its wellness benefits, with Americans indicating stronger willingness than Australian respondents. The potential of meat consumption to improve overall wellness among red meat eaters was a dominant factor influencing consumers' WTP more. Other factors that increased WTP included frequency of meat consumption, physical exercise, sleep quality, number of children in a household, partnership status, and economic position. Outcomes from this study highlight a unique opportunity for the meat industry to position meat on its qualities that include wellness improvement if backed up with robust scientific evidence.

A comprehensive evaluation of online inhaler use techniques for obstructive airway disease.

BACKGROUND: Pulmonary inhaler therapy is a core treatment modality for >600 million individuals affected by obstructive airways disease globally. Poor inhaler technique is associated with reduced disease control and increased health care utilization; however, many patients rely on the internet as a technical resource. This study assesses the content and quality of online resources describing inhaler techniques. METHODS: A Google search was conducted in April 2023 capturing the top 5 search results for 12 common inhaler devices. Websites were compared to product monographs for preparation/first use, inhalational technique, and post-usage/device care. They were also assessed using accepted quality metrics (GQS, DISCERN, JAMA Benchmark scores) and clinically relevant aspects based on the literature and consensus statements. RESULTS: Websites regularly excluded critical steps important for proper inhaler technique. They performed best on information related directly to inhalation technique (average median score 78%), whereas steps related to preparation/first use (58%) or post-usage/device care (50%) were less frequently addressed. Median GQS, DISCERN, and JAMA Benchmark scores were 3 [IQR 3-4], 3 [IQR 2-4], and 1 [IQR 1-3], respectively. Clinically relevant factors were only addressed in about one-fifth of websites with no websites addressing smoking cessation, environmental considerations, or risk factors for poor technique. CONCLUSIONS: This study highlights gaps in online resources describing inhaler technique, particularly related to preparation/first use and post-usage/device care steps. Clinically relevant factors were rarely addressed across websites. Improvements in these areas could lead to enhanced inhaler technique and clinical outcomes.

Protective behaviors against COVID-19 and their association with psychological factors in China and South Korea during the Omicron wave: a comparative study.

OBJECTIVES: We aimed to explore the level of protective behaviors against COVID-19 and its association with psychological factors in China and South Korea during the Omicron wave. STUDY DESIGN: Cross-sectional study. METHODS: We conducted a population-based cross-sectional survey from March 15 to 30, 2023 in China and South Korea. Demographic characteristics, health status, protective behaviors, and psychological factors (including perceived risks, efficacy belief, attribution of disease, fear of COVID-19, trust and evaluation, fatalism, resilience, and pandemic fatigue) were investigated. After adjusting for sociodemographic and health-related factors, multivariable regression models were constructed to explore the psychological influencing factors of protective behavior. RESULTS: A total of 3000 participants from China and 1000 participants from Korea were included in the final analysis. The mean performance score for protective behaviors among all respondents was 2.885 in China and 3.139 in Korea, with scores ranging from 1 to 4. In China, performance scores were higher in those who were female, aged 30-39, employed, married, living in urban areas, having the highest income level, having the best subjective health status, and having a history of chronic disease (P-value <0.05). In Korea, performance scores were higher for individuals who were female, over 50 years old, educated to high school or below, unemployed, married, had a history of chronic disease, and had never been infected with SARS-CoV-2 (P-value <0.05). In the multivariable regression model, perceived severity (ß = 0.067), attribution of disease (ß = 0.121), fear of COVID-19 (ß = 0.128), trust and evaluation (ß = 0.097), psychological resilience (ß = 0.068), and efficacy belief (ß = 0.216) were positively associated with the performance scores, pandemic fatigue (ß = -0.089) was negatively associated with performance scores in China (P-value <0.05). However, in Korea, perceived susceptibility (ß = 0.075), fear of COVID-19 (ß = 0.107), and efficacy belief (ß = 0.357) were positively associated with protective behaviors (P-value <0.05), trust and evaluation (ß = -0.078) and pandemic fatigue (ß = -0.063) were negatively associated with performance scores (P-value <0.05). CONCLUSIONS: Populations in both China and Korea demonstrated great compliance with protective behaviors during the Omicron wave. Because of the sociocultural, economic, and political differences, there were differences in the association between psychological factors and protective behaviors in the two countries. This study, from the perspective of psychological factors in different cultural contexts, would provide references for increasing adherence to protective guidelines in future outbreaks of emerging infectious diseases.

Risk factors of developing nonalcoholic fatty liver disease after pancreatic resection: a systematic review and meta-analysis.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) occurs in 10% to 40% of patients after pancreatic resection. Pancreatic exocrine insufficiency (PEI) is thought to be closely associated with NAFLD; however, the mechanism of NAFLD is not clearly understood. We perform a systematic review and meta-analysis to better understand the risk factors of NAFLD. METHODS: A systematic literature search was performed in the MEDLINE database. Studies focused on the risk factors associated with NAFLD in patients undergoing pancreatectomy. The odds ratios (ORs) denoting the association of risk factors with NAFLD after resection were curated. RESULTS: Of 814 published articles, 26 studies met the inclusion criteria. Combined, these studies included clinical data on 4055 patients. The pooled incidence of NAFLD was 29% (23%-35%). Among the various risk factors analyzed, the following had a significant likelihood of NAFLD on forest plot analysis: female gender (OR, 2.44), pancreatic ductal adenocarcinoma (OR, 2.11), portal vein or superior mesenteric vein resection (OR, 1.99), dissection of nerve plexus around the superior mesenteric artery (OR, 1.93), and adjuvant chemotherapy (OR, 1.58). Only 2 studies investigated 2 different measurements of quantitative PEI, which could not be used for analysis. Owing to heterogeneity of studies, pancreatic remanent volume, which is considered a marker for PEI could not be evaluated. Pancreatic enzyme replacement therapy (PERT) was not associated with NAFLD. CONCLUSION: Numerous factors are associated with NAFLD after pancreatectomy. Previous research shows that PEI may be associated with NAFLD; however, this could not be compared in our meta-analysis. Further research is required to study the role of PERT in NAFLD.

Enhanced cholera surveillance to improve vaccination campaign efficiency.

Systematic testing for Vibrio cholerae O1 is rare, which means that the world's limited supply of oral cholera vaccines (OCVs) may not be delivered to areas with the highest true cholera burden. Here we used a phenomenological model with subnational geographic targeting and fine-scale vaccine effects to model how expanding V. cholerae testing affected impact and cost-effectiveness for preventive vaccination campaigns across different bacteriological confirmation and vaccine targeting assumptions in 35 African countries. Systematic testing followed by OCV targeting based on confirmed cholera yielded higher efficiency and cost-effectiveness and slightly fewer averted cases than status quo scenarios targeting suspected cholera. Targeting vaccine to populations with an annual incidence rate greater than 10 per 10,000, the testing scenario averted 10.8 (95% prediction interval (PI) 9.4-12.6) cases per 1,000 fully vaccinated persons while the status quo scenario averted 6.9 (95% PI 6.0-7.8) cases per 1,000 fully vaccinated persons. In the testing scenario, testing costs increased by US$31 (95% PI 25-39) while vaccination costs reduced by US$248 (95% PI 176-326) per averted case compared to the status quo. Introduction of systematic testing into cholera surveillance could improve efficiency and reach of global OCV supply for preventive vaccination.

Language Disparities in Caregiver Satisfaction with Physician Communication at Well Visits from 0-2 Years.

OBJECTIVE: This study aimed to describe caregiver satisfaction with physician communication over the first two years of life and examine differences by preferred language and the relationship to physician continuity. METHODS: Longitudinal data were collected at well visits (2 months to 2 years) from participants in a randomized controlled trial to prevent childhood obesity. Satisfaction with communication was assessed using the validated Communication Assessment Tool (CAT) questionnaire. Changes in the odds of optimal scores were estimated in mixed-effects logistic regression models to evaluate the associations between satisfaction over time and language, interpreter use, and physician continuity. RESULTS: Of 865 caregivers, 35% were Spanish-speaking. Spanish-speaking caregivers without interpreters had lower odds of an optimal satisfaction score compared with English speakers during the first 2 years, beginning at 2 months [OR 0.64 (95% CI: 0.43, 0.95)]. There was no significant difference in satisfaction between English-speaking caregivers and Spanish-speaking caregivers with an interpreter. The odds of optimal satisfaction scores increased over time for both language groups. For both language groups, odds of an optimal satisfaction score decreased each time a new physician was seen for a visit [OR 0.82 (95% CI: 0.69, 0.97)]. CONCLUSION: Caregiver satisfaction with physician communication improves over the first two years of well-child visits for both English- and Spanish-speakers. A loss of physician continuity over time was also associated with lower satisfaction. Future interventions to ameliorate communication disparities should ensure adequate interpreter use for primarily Spanish-speaking patients and address continuity issues to improve communication satisfaction.

Treatment of External Fixator Pin Tract Deep Infections With an Antibiotic "Sparkler".

Pin tract infections are virtually universal complications with the use of external fixation. While most are superficial and respond to oral antibiotics and local care, septic loosening may occur at the bone-pin interface, which may lead to instability of the fixator, catastrophic failure, fracture, and long-term osteomyelitis. Classification systems and prevention protocols have been developed to address this ubiquitous complication. Treatment of severe pin tract infections often requires debridement, parenteral antibiotics, and removal of the offending pin or the entire external fixator. In cases of osteomyelitic pin tracks, a sizable cavity is often present. We describe a simple technique for treatment of deep bone pin tract infection through the use of debridement, irrigation, and an antibiotic "sparkler," which is a specially prepared percutaneous implant of antibiotic laden bone cement.Levels of Evidence: Level 5.

Management of acute colonic pseudo-obstruction: opportunities to improve care?

BACKGROUND: Acute colonic pseudo-obstruction (ACPO) is a functional bowel obstruction characterised by colonic dilatation in the absence of mechanical obstruction on imaging. Complications include bowel ischaemia, perforation and death. The aim of this study was to explore outcomes for patients treated for ACPO and to assess adherence to current ACPO treatment guidelines. METHODS: This is a retrospective service evaluation and included patients with a diagnosis of ACPO between 1 March 2018 and 31 March 2023. Process measures were identified following discussion with the clinical team from published guidance. Patients were identified using clinical coding and radiological text reports. Cases were eligible for inclusion if they had radiologically confirmed ACPO. Data were collected following review of patient notes into Microsoft Excel. Descriptive analysis was performed with no formal statistical assessment. RESULTS: A total of 45 patients were identified, of whom 13 were admitted under general surgery. All patients received admission bloods (n=45). Nearly all patients had computed tomography imaging (43/45, 96%). Only 3/45 (6.7%) of the patients received optimal conservative management (intravenous infusion, nil by mouth, flatus tube, treatment of reversible causes). In all, 11/45 (24%) required further treatment, of whom 7 received this within 72 h. The leading (11/45) complication following diagnosis of ACPO was hospital-acquired pneumonia. Mortality was seen in 9/45. CONCLUSIONS: ACPO is often managed remotely by general surgeons. This may impact on the quality of conservative management, and timeliness of endoscopic or pharmacological intervention. Further work is needed to optimise management.

Incidence of mental health conditions following pediatric hospital admissions: analysis of a national database.

Introduction: Despite increasing survival of children following hospitalization, hospitalization may increase iatrogenic risk for mental health (MH) disorders, including acute stress, post-traumatic stress, anxiety, or depression. Using a population-based retrospective cohort study, we assessed the rates of new MH diagnoses during the 12 months after hospitalization, including the moderating effects of ICU exposure. Study design/methods: This was a retrospective case control study using the Truven Health Analytics insurance database. Inclusion criteria included children aged 3-21 years, insurance enrollment for >12 months before and after hospital admission. We excluded children with hospitalization 2 years prior to index hospitalization and those with prior MH diagnoses. We extracted admission type, ICD-10 codes, demographic, clinical, and service coordination variables from the database. We established age- and sex-matched cohorts of non-hospitalized children. The primary outcome was a new MH diagnosis. Multivariable regression methods examined the risk of incident MH disorder(s) between hospitalized and non-hospitalized children. Among hospitalized children, we further assessed effect modification from ICU (vs. non-ICU) stay, admission year, length of stay, medical complexity, and geographic region. Results: New MH diagnoses occurred among 19,418 (7%) hospitalized children, 3,336 (8%) ICU-hospitalized children and 28,209 (5%) matched healthy controls. The most common MH diagnoses were anxiety (2.5%), depression (1.9%), and stress/trauma (2.2%) disorders. Hospitalization increased the odds of new MH diagnoses by 12.3% (OR: 1.123, 95% CI: 1.079-1.17) and ICU-hospitalization increased these odds by 63% (OR: 1.63, 95% CI: 1.483-1.79) as compared to matched, non-hospitalized children. Children with non-complex chronic diseases (OR: 2.91, 95% CI: 2.84-2.977) and complex chronic diseases (OR: 5.16, 95% CI: 5.032-5.289) had a substantially higher risk for new MH diagnoses after hospitalization compared to patients with acute illnesses. Conclusion: Pediatric hospitalization is associated with higher, long-term risk of new mental health diagnoses, and ICU hospitalization further increases that risk within 12 months of the acute episode. Acute care hospitalization confers iatrogenic risks that warrant long-term mental and behavioral health follow-up.

Nightshift work and irregular menstrual cycle: 8-year follow-up cohort study.

BACKGROUND: Irregular menstruation is a major health problem among women, although its association with nightshift work remains controversial. AIMS: To study the association between nightshift work and irregular menstrual cycle among female workers and investigate any differences according to sleep quality, working hours or obesity. METHODS: This study included female workers who underwent health examinations from 2012 to 2019. Nightshift work, working hours, sleep quality and menstrual cycles were assessed using self-administered questionnaires. Irregular menstrual cycle was defined as self-reported irregular or ≥36 days. Adjusted odds ratios and 95% confidence intervals (CIs) were calculated by multivariable logistic regression; adjusted hazard ratios (95% CIs) for incident irregular menstrual cycle were calculated by Cox proportional hazard models with time-dependent analysis. RESULTS: The study participants were 87 147 in the cross-sectional study and 41 516 in the longitudinal study. After adjusting for all covariates in the cross-sectional analyses, the odds ratio for prevalent irregular menstrual cycle among female nightshift workers versus the reference was 1.26 (95% CI 1.2-1.33). In the cohort study, the adjusted hazard ratio for incident irregular menstrual cycle among nightshift workers was 1.95 (95% CI 1.61-2.35) in the period after 6 years. No significant differences were observed among subgroups stratified by sleep quality, working hours or obesity. CONCLUSIONS: Nightshift work is associated with an increased risk of both prevalent and incident irregular menstrual cycle in female workers without significant interactions by sleep quality, working hours or obesity.

The hindbrain and cortico-reticular pathway in adolescent idiopathic scoliosis.

AIM: To characterise the corticoreticular pathway (CRP) in a case-control cohort of adolescent idiopathic scoliosis (AIS) patients using high-resolution slice-accelerated readout-segmented echo-planar diffusion tensor imaging (DTI) to enhance the discrimination of small brainstem nuclei in comparison to automated whole-brain volumetry and tractography and their clinical correlates. MATERIALS AND METHODS: Thirty-four participants (16 AIS patients, 18 healthy controls) underwent clinical and orthopaedic assessments and brain magnetic resonance imaging (MRI) on a 3 T MRI machine. Automated whole-brain volume-based morphometry, tract-based spatial statistics analysis, and manual CRP tractography by two independent raters were performed. Intra-rater and inter-rater agreement of DTI metrics from CRP tractography were assessed by intraclass correlation coefficient. Normalised structural brain volumes and DTI metrics were compared between groups using Student's t-tests. Linear correlation analysis between imaging parameters and clinical scores was also performed. RESULTS: AIS patients demonstrated a significantly larger pons volume compared to controls (p=0.006). Significant inter-side CRP differences in mean (p=0.02) and axial diffusivity (p=0.01) were found in patients only. Asymmetry in CRP fractional anisotropy significantly correlated with the Cobb angle (p=0.03). CONCLUSION: Relative pontine hypertrophy and asymmetry in CRP DTI metrics suggest central supranuclear inter-hemispheric imbalance in AIS, and support the role of the CRP in axial muscle tone. Longitudinal evaluation of CRP DTI metrics in the prediction of AIS progression may be clinically relevant.

A Diversity Covering (DiCo) Plasmodium vivax apical membrane antigen-1 vaccine adjuvanted with RFASE/RSL10 yields high levels of growth-inhibitory antibodies.

Plasmodium vivax malaria is increasingly recognized as a major global health problem and the socio-economic impact of P.vivax-induced burden is huge. Vaccine development against P. vivax malaria has been hampered by the lack of an in vitro culture system and poor access to P. vivax sporozoites. The recent generation of Plasmodium falciparum parasites that express a functional P. vivax AMA1 molecule has provided a platform for in vitro evaluation of PvAMA1 as a potential blood stage vaccine. Three so-called PvAMA1 Diversity Covering (DiCo) proteins were designed to assess their potential to induce a functional and broad humoral immune response to the polymorphic PvAMA1 molecule. Rabbits were immunized with the mixture of three, Pichia-produced, PvAMA1 DiCo proteins, as well as with 2 naturally occurring PvAMA1 alleles. For these three groups, the experimental adjuvant raffinose fatty acid sulfate ester (RFASE) was used, while in a fourth group the purified main mono-esterified constituent (RSL10) of this adjuvant was used. Animals immunized with the mixture of the three PvAMA1 DiCo proteins in RFASE showed high anti-PvAMA1 antibody titers against three naturally occurring PvAMA1variants while also high growth-inhibitory capacity was observed against P. falciparum parasites expressing PvAMA1. This supports further clinical development of the PvAMA1 DiCo mixture as a potential malaria vaccine. However, as the single allele PvAMA1 SalI-group showed similar characteristics in antibody titer and inhibition levels as the PvAMA1 DiCo mixture-group, this raises the question whether a mixture is really necessary to overcome the polymorphism in the vaccine candidate. RFASE induced strong humoral responses, as did the animals immunized with the purified component, RSL10. This suggests that RSL10 is the active ingredient. However, one of the RSL10-immunized animal showed a delayed response, necessitating further research into the clinical development of RSL10.