[Core data set for real world data in multiple sclerosis: customization for latin america from a global task force recommendation]

INTRODUCTION

The primary objective of the core data set is to reduce heterogeneity and promote harmonization among data sources in EM, thereby reducing the time needed to execute real life data collection efforts. Recently, a group led by the Multiple Sclerosis Data Alliance has developed a core data set for collecting real-world data on multiple sclerosis (MS) globally. Our objective was to adapt this global data set to the needs of Latin America, so that it can be implemented by the registries already developed and in the process of development in the region.

MATERIAL AND METHODS

A working group was formed regionally, the core data set created globally was adapted (translation process into Spanish, incorporation of regional variables and consensus on variables to be used). Consensus was obtained through the remote Delphi methodology of a round of questionnaires and remote discussion of the core data set variables.

RESULTS

A total of 25 professionals from Latin America carried out the adaptation process between November 2022 and July 2023. Agreement was established on a core data set of nine categories and 45 variables, version 2023 to suggest its implementation in developed or developing registries, and MS cohorts in the region.

CONCLUSION

The core data set seeks to harmonize the variables collected by registries and cohorts in MS in Latin America in order to facilitate said collection and allow collaboration between sources. Its implementation will facilitate real life data collection and collaboration in the region.

Association between Immunogenicity of a Monovalent Parenteral P2-VP8 Subunit Rotavirus Vaccine and Fecal Shedding of Rotavirus following Rotarix Challenge during a Randomized, Double-Blind, Placebo-Controlled Trial

A correlate of protection for rotavirus (RV) has not been consistently identified. Shedding of RV following an oral rotavirus vaccine (ORV) challenge has been investigated as a potential model to assess protection of parenteral RV vaccines. We previously showed that shedding of a challenge ORV dose was significantly reduced among recipients of a parenteral monovalent RV subunit vaccine (P2-VP8-P[8]) compared to placebo recipients. This secondary data analysis assessed the association between fecal shedding of RV, as determined by ELISA one week after receipt of a Rotarix challenge dose at 18 weeks of age, and serum RV-specific antibody responses, one and six months after vaccination with the third dose of the P2-VP8-P[8] vaccine or placebo. We did not find any association between serum RV-specific immune responses measured one month post-P2-VP8-P[8] vaccination and fecal shedding of RV post-challenge. At nine months of age, six months after the third P2-VP8-P[8] or placebo injection and having received three doses of Rotarix, infants shedding RV demonstrated higher immune responses than non-shedders, showing that RV shedding is reflective of vaccine response following ORV. Further evaluation is needed in a larger sample before fecal shedding of an ORV challenge can be used as a measure of field efficacy in RV vaccine trials.

Effects of an early rehabilitation program for adult cystic fibrosis patients during hospitalization: a randomized clinical trial

There is little information on pulmonary rehabilitation in patients with cystic fibrosis (CF) with pulmonary exacerbation. This study aimed to evaluate the effects of an early rehabilitation program on lung function, muscle strength, inflammatory markers, and quality of life in adults with CF hospitalized for pulmonary exacerbation. In this randomized controlled trial, 19 patients were included in the intervention group and 15 in the control group. The intervention group underwent an early rehabilitation program for 14 days after admission. All patients underwent spirometry, one-repetition maximum tests (1RM), and the 6-min walk test, and answered the Revised Cystic Fibrosis Questionnaire (CFQ-R) for quality of life and the International Physical Activity Questionnaire. Serum levels of interleukin and tumor necrosis factor alpha (TNF-α) were measured. In the intervention group, there were increases in 1RM biceps (P=0.009), triceps (P=0.005), shoulder abductors (P=0.002), shoulder flexors (P=0.004), hamstrings (P<0.001), and quadriceps values (P<0.001). In addition, there were improvements in CFQ-R-emotion (P=0.002), treatment burden (P=0.002), vitality (P=0.011), and physical scores (P=0.026), and a reduction in the Borg resting fatigue score (P=0.037). The interleukins levels did not change after the intervention. In adult CF patients with pulmonary exacerbation, early hospital rehabilitation had a significant impact on improving resting fatigue, muscle strength, and quality of life.

Richer than Gold: the fungal biodiversity of Reserva Los Cedros, a threatened Andean cloud forest

BACKGROUND

Globally, many undescribed fungal taxa reside in the hyperdiverse, yet undersampled, tropics. These species are under increasing threat from habitat destruction by expanding extractive industry, in addition to global climate change and other threats. Reserva Los Cedros is a primary cloud forest reserve of ~ 5256 ha, and is among the last unlogged watersheds on the western slope of the Ecuadorian Andes. No major fungal survey has been done there, presenting an opportunity to document fungi in primary forest in an underrepresented habitat and location. Above-ground surveys from 2008 to 2019 resulted in 1760 vouchered collections, cataloged and deposited at QCNE in Ecuador, mostly Agaricales sensu lato and Xylariales. We document diversity using a combination of ITS barcode sequencing and digital photography, and share the information via public repositories (GenBank & iNaturalist).

RESULTS

Preliminary identifications indicate the presence of at least 727 unique fungal species within the Reserve, representing 4 phyla, 17 classes, 40 orders, 101 families, and 229 genera. Two taxa at Los Cedros have recently been recommended to the IUCN Fungal Red List Initiative (Thamnomyces chocöensis Læssøe and "Lactocollybia" aurantiaca Singer), and we add occurrence data for two others already under consideration (Hygrocybe aphylla Læssøe & Boertm. and Lamelloporus americanus Ryvarden).

CONCLUSIONS

Plants and animals are known to exhibit exceptionally high diversity and endemism in the Chocó bioregion, as the fungi do as well. Our collections contribute to understanding this important driver of biodiversity in the Neotropics, as well as illustrating the importance and utility of such data to conservation efforts.

RESUMEN

Antecedentes: A nivel mundial muchos taxones fúngicos no descritos residen en los trópicos hiper diversos aunque continúan submuestreados. Estas especies están cada vez más amenazadas por la destrucción del hábitat debido a la expansión de la industria extractivista además del cambio climático global y otras amenazas. Los Cedros es una reserva de bosque nublado primario de ~ 5256 ha y se encuentra entre las últimas cuencas hidrográficas no explotadas en la vertiente occidental de los Andes ecuatorianos. Nunca antes se ha realizado un estudio de diversidad micológica en el sitio, lo que significa una oportunidad para documentar hongos en el bosque primario, en hábitat y ubicación subrepresentatadas. El presente estudio recopila información entre el 2008 y 2019 muestreando material sobre todos los sustratos, reportando 1760 colecciones catalogadas y depositadas en el Fungario del QCNE de Ecuador, en su mayoría Agaricales sensu lato y Xylariales; además se documenta la diversidad mediante secuenciación de códigos de barras ITS y fotografía digital, la información está disponible en repositorios públicos digitales (GenBank e iNaturalist).

RESULTADOS

La identificación preliminar indica la presencia de al menos 727 especies únicas de hongos dentro de la Reserva, que representan 4 filos, 17 clases, 40 órdenes, 101 familias y 229 géneros. Recientemente dos taxones en Los Cedros se recomendaron a la Iniciativa de Lista Roja de Hongos de la UICN (Thamnomyces chocöensis Læssøe y "Lactocollybia" aurantiaca Singer) y agregamos datos de presencia de otros dos que ya estaban bajo consideración (Hygrocybe aphylla Læssøe & Boertm. y Lamelloporus americanus Ryvarden).

CONCLUSIONES

Se sabe que plantas y animales exhiben una diversidad y endemismo excepcionalmente altos en la bioregión del Chocó y los hongos no son la excepción. Nuestras colecciones contribuyen a comprender este importante promotor de la biodiversidad en el Neotrópico además de ilustrar la importancia y utilidad de dichos datos para los esfuerzos de conservación.

Prospection and identification of backcrossings of traditional-heritage peruvian grapevine cultivars (Vitis vinifera L.) from Ica and Cañete Valleys

La vid (Vitis vinifera L.) fue introducida en Sudamérica durante el siglo XVI. En los valles de Ica y Cañete, los nombres "Quebranta Mollar", "Mollar" y "Prieta Mollar" son comúnmente utilizados en referencia a los diferentes colores de las bayas de estas variedades dentro de un mismo racimo. Esta heterogeneidad en cuanto al color de las bayas, sumada a los antecedentes históricos, sugieren que otras variedades, además de Quebranta y Mollar Cano, podrían estar implicadas en esta denominación genérica "Mollar". En este trabajo se identificaron diferentes fenotipos correspondientes a algunas variedades utilizadas en la elaboración de vino y Pisco. Para ello, 10 accesiones fueron recolectadas en 9 viñedos diferentes (valles de Ica y Cañete), y analizadas utilizando 20 marcadores moleculares y 25 descriptores morfológicos según la OIV. Nuestros resultados mostraron que las muestras recolectadas correspondieron a 5 genotipos, tres cultivares tradicionales y dos genotipos desconocidos no registrados previamente. Los tres cultivares conocidos fueron Listan Prieto, Quebranta y Mollar Cano. Las dos accesiones correspondientes a variedades no conocidas previamente fueron Mollar de Ica y Prieta Mollar, generadas a partir de retrocruzamientos entre Quebranta y sus progenitores. También se identificaron diferentes variaciones fenotípicas de Quebranta, lo cual enriquece la diversidad vitícola peruana.

Controlled Human Infection Models To Accelerate Vaccine Development

The timelines for developing vaccines against infectious diseases are lengthy, and often vaccines that reach the stage of large phase 3 field trials fail to provide the desired level of protective efficacy. The application of controlled human challenge models of infection and disease at the appropriate stages of development could accelerate development of candidate vaccines and, in fact, has done so successfully in some limited cases. Human challenge models could potentially be used to gather critical information on pathogenesis, inform strain selection for vaccines, explore cross-protective immunity, identify immune correlates of protection and mechanisms of protection induced by infection or evoked by candidate vaccines, guide decisions on appropriate trial endpoints, and evaluate vaccine efficacy. We prepared this report to motivate fellow scientists to exploit the potential capacity of controlled human challenge experiments to advance vaccine development. In this review, we considered available challenge models for 17 infectious diseases in the context of the public health importance of each disease, the diversity and pathogenesis of the causative organisms, the vaccine candidates under development, and each model's capacity to evaluate them and identify correlates of protective immunity. Our broad assessment indicated that human challenge models have not yet reached their full potential to support the development of vaccines against infectious diseases. On the basis of our review, however, we believe that describing an ideal challenge model is possible, as is further developing existing and future challenge models.

Early identification of patients with Chagas disease at risk of developing cardiomyopathy using 2-D speckle tracking strain

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What is already known about this subject? Speckle-tracking strain echocardiography (STE) is added to conventional echocardiography and has been shown to detect subclinical myocardial contractile dysfunction before a reduction in LVEF.

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What does this study add? In this study, we evaluate the utility of LV STE for predicting worsening CCC in patients with Chagas disease.

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How might this impact on clinical practice? Screening for changes in STE-based Global Longitudinal Strain (GLS) may provide a non-invasive approach to identify patients who could benefit from earlier management, such as more frequent follow-up or initiation of treatment.

Background

Chagas disease is an endemic protozoan disease with high prevalence in Latin America. Of those infected, 20–30% will develop chronic Chagas cardiomyopathy (CCC) however, prediction using existing clinical criteria remains poor. In this study, we investigated the utility of left ventricular (LV) echocardiographic speckle-tracking global longitudinal strain (GLS) for early detection of CCC.

Methods and results

139 asymptomatic T. cruzi seropositive subjects with normal heart size and normal LV ejection fraction (EF) (stage A or B) were enrolled in this prospective observational study and underwent paired echocardiograms at baseline and 1-year follow-up. Progressors were participants classified as stage C or D at follow-up due to development of symptoms of heart failure, cardiomegaly, or decrease in LVEF. LV GLS was calculated as the average peak systolic strain of 16 LV segments. Measurements were compared between participants who progressed and did not progress by two-sample t-test, and the odds of progression assessed by multivariable logistic regression. Of the 139 participants, 69.8% were female, mean age 55.8 ± 12.5 years, with 12 (8.6%) progressing to Stage C or D at follow-up. Progressors tended to be older, male, with wider QRS duration. LV GLS was −19.0% in progressors vs. –22.4% in non-progressors at baseline, with 71% higher odds of progression per +1% of GLS (adjusted OR 1.71, 95% CI 1.20–2.44, p = 0.003).

Conclusion

Baseline LV GLS in participants with CCC stage A or B was predictive of progression within 1-year and may guide timing of clinical follow-up and promote early detection or treatment.

Immunogenicity and safety of two monovalent rotavirus vaccines, ROTAVAC® and ROTAVAC 5D® in Zambian infants

BACKGROUND AND AIMS

ROTAVAC® (frozen formulation stored at -20 °C) and ROTAVAC 5D® (liquid formulation stable at 2-8 °C) are rotavirus vaccines derived from the 116E human neonatal rotavirus strain, developed and licensed in India. This study evaluated and compared the safety and immunogenicity of these vaccines in an infant population in Zambia.

METHODS

We conducted a phase 2b, open-label, randomized, controlled trial wherein 450 infants 6 to 8 weeks of age were randomized equally to receive three doses of ROTAVAC or ROTAVAC 5D, or two doses of ROTARIX®. Study vaccines were administered concomitantly with routine immunizations. Blood samples were collected pre-vaccination and 28 days after the last dose. Serum anti-rotavirus IgA antibodies were measured by ELISA, with WC3 and 89-12 rotavirus strains as viral lysates in the assays. The primary analysis was to assess non-inferiority of ROTAVAC 5D to ROTAVAC in terms of the geometric mean concentration (GMC) of serum IgA (WC3) antibodies. Seroresponse and seropositivity were also determined. Safety was evaluated as occurrence of immediate, solicited, unsolicited, and serious adverse events after each dose.

RESULTS

The study evaluated 388 infants in the per-protocol population. All three vaccines were well tolerated and immunogenic. The post-vaccination GMCs were 14.0 U/mL (95% CI: 10.4, 18.8) and 18.1 U/mL (95% CI: 13.7, 24.0) for the ROTAVAC and ROTAVAC 5D groups, respectively, yielding a ratio of 1.3 (95% CI: 0.9, 1.9), thus meeting the pre-set non-inferiority criteria. Solicited and unsolicited adverse events were similar across all study arms. No death or intussusception case was reported during study period.

CONCLUSIONS

Among Zambian infants, both ROTAVAC and ROTAVAC 5D were well tolerated and the immunogenicity of ROTAVAC 5D was non-inferior to that of ROTAVAC. These results are consistent with those observed in licensure trials in India and support use of these vaccines across wider geographical areas.

Cyclooxygenase 2 messenger RNA levels in canine follicular cells: interrelationship with GDF-9, BMP-15, and progesterone

Cyclooxygenase 2 (COX-2) encoded by the Cox-2 gene within the periovulatory follicles is a critical mediator of oocyte development. Growth differentiation factor 9 (GDF-9) and bone morphogenetic protein 15 (BMP-15) participate in the modulation of certain target genes in the ovary, possibly influencing the Cox-2 gene expression. However, this relationship has not been characterized in canines. This study aimed to examine the possible relationships among BMP-15, GDF-9, progesterone, and Cox-2 gene expression in granulosa-cumulus cells in dogs. Granulosa cells from antral follicles and their corresponding cumulus-oocyte complexes and follicular fluid (FF) were separately obtained from 56 ovaries collected from adult bitches at estrus (n = 15) and proestrus (n = 13) after ovariohysterectomy. Total RNA extraction was performed in follicular cells, and Cox-2 gene expression was assessed by quantitative PCR analysis. Progesterone, BMP-15, and GDF-9 were determined in the FF samples using ELISA assays. Cumulus-oocyte complexes were subjected to in vitro maturation (IVM) with or without (control) recombinant GDF-9 and BMP-15. After 72 h of culture, Cox-2 transcript analyses were performed in cumulus cells via quantitative PCR. Data were evaluated by ANOVA. An increase (P < 0.05) in Cox-2 messenger RNA levels was observed in follicular cells from follicles at estrus with respect to those at proestrus. However, the levels of BMP-15 and GDF-9 in FF decreased (P < 0.05), whereas progesterone increased (P < 0.05) from the proestrus phase to the estrus phase. The expression of Cox-2 gene in cumulus cells was 4-fold greater (P < 0.01) than that in the control when both growth factors were added to the IVM culture. In conclusion, although BMP-15 together with GDF-9 appears to upregulate the levels of Cox-2 transcripts during IVM, the inverse relationship of these paracrine factors with Cox-2 gene expression and the positive correlation of progesterone with Cox-2 transcripts suggest that the high progesterone levels could be more relevant in the local mechanisms regulating the Cox-2 gene expression.

Next-generation rotavirus vaccine developers meeting: Summary of a meeting sponsored by PATH and the bill & melinda gates foundation (19-20 June 2019, Geneva)

Despite the contribution of currently licensed live, oral rotavirus vaccines (LORVs) to alleviating the burden of severe disease and death from rotavirus gastroenteritis, those vaccines have proven less efficacious in resource-limited settings than in high- and middle-income countries. It has been proposed that the residual burden of rotavirus disease might be overcome with parenterally administered vaccines, or next-generation rotavirus vaccines (NGRV). To better define the progress of development of these vaccines, a meeting of vaccine developers and manufacturers engaged in NGRV research and development was convened in Geneva in June 2019. Several NRGVs are in various stages of preclinical development, and two have already entered clinical testing. The vaccine platforms include subunit protein, inactivated whole virus, virus-like particle and RNA-based vaccines. Meeting participants included groups involved in NGRV development, scientists investigating correlates of protection of rotavirus vaccines, and representatives of international organizations with insight into considerations for vaccine introduction. This report summarizes the presentations shared at the meeting.

Low-dose and oral exposure to SARS-CoV-2 may help us understand and prevent severe COVID-19

Background

The effectiveness and sustainability of current public health interventions designed to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission remain of great concern in many settings, especially in the absence of a transmission-preventing vaccine.

Hypothesis

It was hypothesized that a more targeted set of interventions focusing on preventing severe coronavirus disease 2019 (COVID-19), rather than SARS-CoV-2 transmission, would be less disruptive to society. To identify these, it would be helpful to better understand how the infecting dose of SARS-CoV-2 and its route of infection influence the clinical outcome, immunological protection, and likelihood of onward transmission.

Proposal

It is suggested that carefully controlled human infection model (CHIM) studies involving intranasal and oral administration of progressively increasing doses of SARS-CoV-2, starting with low levels, to healthy young adult volunteers may be the most expeditious and definitive way to answer these questions. Such studies would differ in objective from CHIM proposals designed to expedite vaccine development, although the latter might be adapted to address some of the questions raised here.

Implications

Results from the studies proposed here could help elucidate the relationship of infection to COVID-19 and thereby provide a scientific basis for more targeted and sustainable application of public health control measures, and inform the design of improved immunotherapeutics and more targeted vaccine development.

Double-Blind, Randomized, Placebo-Controlled Phase III Clinical Trial to Evaluate the Efficacy and Safety of treating Healthcare Professionals with the Adsorbed COVID-19 (Inactivated) Vaccine Manufactured by Sinovac - PROFISCOV: A structured summary of a study protocol for a randomised controlled trial

Objectives

To evaluate the efficacy of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac in symptomatic individuals, with virological confirmation of COVID-19, two weeks after the completion of the two-dose vaccination regimen, aged 18 years or older who work as health professionals providing care to patients with possible or confirmed COVID-19.

To describe the occurrence of adverse reactions associated with the administration of each of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac up to one week after vaccination in Adults (18-59 years of age) and Elderly (60 years of age or more).

Trial design

This is a Phase III, randomized, multicenter, endpoint driven, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac.

The adsorbed vaccine COVID-19 (inactivated) produced by Sinovac (product under investigation) will be compared to placebo. Voluntary participants will be randomized to receive two intramuscular doses of the investigational product or the placebo, in a 1: 1 ratio, stratified by age group (18 to 59 years and 60 years or more) and will be monitored for one year by active surveillance of COVID-19. Two databases will be established according to the age groups: one for adults (18-59 years) and one for the elderly (60 years of age or older).

The threshold to consider the vaccine efficacious will be to reach a protection level of at least 50%, as proposed by the World Health Organization and the FDA. Success in this criterion will be defined by sequential monitoring with adjustment of the lower limit of the 95% confidence interval above 30% for the primary efficacy endpoint.

Participants

Healthy participants and / or participants with clinically controlled disease, of both genders, 18 years of age or older, working as health professionals performing care in units specialized in direct contact with people with possible or confirmed cases of COVID-19. Participation of pregnant women and those who are breastfeeding, as well as those intending to become pregnant within three months after vaccination will not be allowed. Participants will only be included after signing the voluntary Informed Consent Form and ensuring they undergo screening evaluation and conform to all the inclusion and exclusion criteria. All the clinical sites are located in Brazil.

Intervention and comparator

Experimental intervention: The vaccine was manufactured by Sinovac Life Sciences (Beijing, China) and contains 3 μg/0.5 mL (equivalent to 600 SU per dose) of inactivated SARS-CoV-2 virus, and aluminium hydroxide as adjuvant.

Control comparator: The placebo contains aluminium hydroxide in a 0.5 mL solution

The schedule of both, experimental intervention and placebo is two 0.5 mL doses IM (deltoid) with a two week interval.

Main outcomes

The primary efficacy endpoint is the incidence of symptomatic cases of virologically confirmed COVID-19 two weeks after the second vaccination. The virological diagnosis will be confirmed by detection of SARS-CoV-2 nucleic acid in a clinical sample.

The primary safety endpoint is the frequency of solicited and unsolicited local and systemic adverse reactions during the period of one week after vaccination according to age group in adult (18-59 years old) and elder (60 years of age or older) subjects. Adverse reactions are defined as adverse events that have a reasonable causal relationship to vaccination.

Randomisation

There will be two randomization lists, one for each age group, based on the investigational products to be administered, i.e., vaccine or placebo at a 1: 1 ratio. Each randomization list will be made to include up to 11,800 (18-59 year-old) adults, and 1,260 elderly (60 y-o and older) participants, the maximum number of participants needed per age group. An electronic central randomization system will be used to designate the investigational product that each participant must receive.

Blinding (masking)

This trial is designed as a double-blind study to avoid introducing bias in the evaluation of efficacy, safety and immunogenicity. The clinical care team, the professionals responsible for the vaccination and the participants will not know which investigational product will be administered. Only pharmacists or nurses in the study who are responsible for the randomization, separation and blinding of the investigational product will have access to unblinded information. The sponsor's operational team will also remain blind.

Numbers to be randomised (sample size)

The total number of participants needed to evaluate efficacy, 13,060 participants, satisfies the needed sample size calculated to evaluate safety. Therefore, the total number obtained for efficacy will be the number retained for the study. Up to 13,060 participants are expected to enter the study, with up to 11,800 participants aged 18 to 59 years and 1,260 elderly participants aged 60 and over. Half of the participants of each group will receive the experimental vaccine and half of them will receive the placebo. The recruitment of participants may be modified as recommended by the Data Safety Monitoring Committee at time of the interim unblinded analysis or blind assessment of the COVID-19 attack rate during the study.

Trial Status

Protocol version 2.0 – 24-Aug-2020. Recruitment started on July 21^st, 2020. The recruitment is expected to conclude in October 2020.

Trial registration

ClinicalTrials.gov Identifier: NCT0445659. Registry on 2 July 2020

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Diarrheal Etiology and Impact of Coinfections on Rotavirus Vaccine Efficacy Estimates in a Clinical Trial of a Monovalent Human-Bovine (116E) Oral Rotavirus Vaccine, Rotavac, India

Background

Rotavirus vaccine efficacy (VE) estimates in low-resource settings are lower than in developed countries. We detected coinfections in cases of severe rotavirus diarrhea in a rotavirus VE trial to determine whether these negatively impacted rotavirus VE estimates.

Methods

We performed TaqMan Array Card assays for enteropathogens on stools from rotavirus enzyme immunoassay–positive diarrhea episodes and all severe episodes (Vesikari score ≥11), from a phase 3 VE trial of Rotavac, a monovalent human–bovine (116E) rotavirus vaccine, carried out across 3 sites in India. We estimated pathogen-specific etiologies of diarrhea, described associated clinical characteristics, and estimated the impact of coinfections on rotavirus VE using a test-negative design.

Results

A total of 1507 specimens from 1169 infants were tested for the presence of coinfections. Rotavirus was the leading cause of severe diarrhea even among vaccinated children, followed by adenovirus 40/41, Shigella/enteroinvasive Escherichia coli, norovirus GII, sapovirus, and Cryptosporidium species. Bacterial coinfections in rotavirus-positive diarrhea were associated with a longer duration of diarrhea and protozoal coinfections with increased odds of hospitalization. Using the test-negative design, rotavirus VE against severe rotavirus gastroenteritis increased from 49.3% to 60.6% in the absence of coinfections (difference, 11.3%; 95% confidence interval, –10.3% to 30.2%).

Conclusions

While rotavirus was the dominant etiology of severe diarrhea even in vaccinated children, a broad range of other etiologies was identified. Accounting for coinfections led to an 11.3% increase in the VE estimate. Although not statistically significant, an 11.3% decrease in VE due to presence of coinfections would explain an important fraction of the low rotavirus VE in this setting.

Safety and immunogenicity of a seasonal trivalent inactivated split influenza vaccine: a double blind, phase III randomized clinical trial in healthy Serbian adults

This study was a phase III, multicenter, double-blind, randomized, placebo-controlled trial to evaluate the safety and immunogenicity of a seasonal trivalent split, inactivated influenza vaccine (TIV) in healthy Serbian adults between the ages of 18 and 65 years. This egg-based vaccine was manufactured by the Institute of Virology, Vaccines and Sera, Torlak, Belgrade, Serbia. A total of 480 participants were assigned randomly in a ratio of 2:1 to receive a single intramuscular dose (0.5 ml) of the vaccine (15 µg of hemagglutinin per strain) or placebo (phosphate-buffered saline). Participants were monitored for safety, including solicited and unsolicited adverse events (AEs) and serious adverse events (SAEs). No SAEs related to vaccination were reported. Injection site pain (51.3%), injection site tenderness (40.4%), tiredness (17.0%), and headache (15.1%) were the most commonly reported solicited events in the vaccine group. Incidence of related unsolicited AEs was low (1.3%) among vaccinees. Hemagglutinin inhibition (HAI) titers were measured before and 21 days after vaccination in 151 participants. Overall, HAI seroconversion rates to H1 and H3 were observed in 90.1% and 76.2% of vaccinees, respectively. For B antigen, it was 51.5%, likely due to high pre-vaccination titers. Post-vaccination seroprotection rates were in the range of 78.2-95.0% for the three antigens. Post-vaccination geometric mean titers (GMT) were at least 3.8 times higher than baseline levels for all the three strains among vaccinees. Overall, the study showed that the vaccine was safe and well tolerated, and induced a robust immune response against all three vaccine strains. ClinicalTrials.gov identifier: NCT02935192, October 17, 2016.

Safety and immunogenicity of a parenteral trivalent P2-VP8 subunit rotavirus vaccine: a multisite, randomised, double-blind, placebo-controlled trial

Background

A monovalent, parenteral, subunit rotavirus vaccine was well tolerated and immunogenic in adults in the USA and in toddlers and infants in South Africa, but elicited poor responses against heterotypic rotavirus strains. We aimed to evaluate safety and immunogenicity of a trivalent vaccine formulation (P2-VP8-P[4],[6],[8]).

Methods

A double-blind, randomised, placebo-controlled, dose-escalation, phase 1/2 study was done at three South African research sites. Healthy adults (aged 18–45 years), toddlers (aged 2–3 years), and infants (aged 6–8 weeks, ≥37 weeks' gestation, and without previous receipt of rotavirus vaccination), all without HIV infection, were eligible for enrolment. In the dose-escalation phase, adults and toddlers were randomly assigned in blocks (block size of five) to receive 30 μg or 90 μg of vaccine, or placebo, and infants were randomly assigned in blocks (block size of four) to receive 15 μg, 30 μg, or 90 μg of vaccine, or placebo. In the expanded phase, infants were randomly assigned in a 1:1:1:1 ratio to receive 15 μg, 30 μg, or 90 μg of vaccine, or placebo, in block sizes of four. Participants, parents of participants, and clinical, data, and laboratory staff were masked to treatment assignment. Adults received an intramuscular injection of vaccine or placebo in the deltoid muscle on the day of randomisation (day 0), day 28, and day 56; toddlers received a single injection of vaccine or placebo in the anterolateral thigh on day 0. Infants in both phases received an injection of vaccine or placebo in the anterolateral thigh on days 0, 28, and 56, at approximately 6, 10, and 14 weeks of age. Primary safety endpoints were local and systemic reactions (grade 2 or worse) within 7 days and adverse events and serious adverse events within 28 days after each injection in all participants who received at least one injection. Primary immunogenicity endpoints were analysed in infants in either phase who received all planned injections, had blood samples analysed at the relevant timepoints, and presented no major protocol violations considered to have an effect on the immunogenicity results of the study, and included serum anti-P2-VP8 IgA, IgG, and neutralising antibody geometric mean titres and responses measured 4 weeks after the final injection in vaccine compared with placebo groups. This trial is registered with ClinicalTrials.gov, NCT02646891.

Findings

Between Feb 15, 2016, and Dec 22, 2017, 30 adults (12 each in the 30 μg and 90 μg groups and six in the placebo group), 30 toddlers (12 each in the 30 μg and 90 μg groups and six in the placebo group), and 557 infants (139 in the 15 μg group, 140 in the 30 μg group, 139 in the 90 μg group, and 139 in the placebo group) were randomly assigned, received at least one dose, and were assessed for safety. There were no significant differences in local or systemic adverse events, or unsolicited adverse events, between vaccine and placebo groups. There were no serious adverse events within 28 days of injection in adults, whereas one serious adverse event occurred in a toddler (febrile convulsion in the 30 μg group) and 23 serious adverse events (four in placebo, ten in 15 μg, four in 30 μg, and five in 90 μg groups) occurred among 20 infants, most commonly respiratory tract infections. One death occurred in an infant within 28 days of injection due to pneumococcal meningitis. In 528 infants (130 in placebo, 132 in 15 μg, 132 in 30 μg, and 134 in 90 μg groups), adjusted anti-P2-VP8 IgG seroresponses (≥4-fold increase from baseline) to P[4], P[6], and P[8] antigens were significantly higher in the 15 μg, 30 μg, and 90 μg groups (99–100%) than in the placebo group (10–29%; p<0·0001). Although significantly higher than in placebo recipients (9–10%), anti-P2-VP8 IgA seroresponses (≥4-fold increase from baseline) to each individual antigen were modest (20–34%) across the 15 μg, 30 μg, and 90 μg groups. Adjusted neutralising antibody seroresponses in infants (≥2·7-fold increase from baseline) to DS-1 (P[4]), 1076 (P[6]), and Wa (P[8]) were higher in vaccine recipients than in placebo recipients: p<0·0001 for all comparisons.

Interpretation

The trivalent P2-VP8 vaccine was well tolerated, with promising anti-P2-VP8 IgG and neutralising antibody responses across the three vaccine P types. Our findings support advancing the vaccine to efficacy testing.

Funding

Bill & Melinda Gates Foundation.

Safety and immunogenicity of a novel 10-valent pneumococcal conjugate vaccine candidate in adults, toddlers, and infants in The Gambia-Results of a phase 1/2 randomized, double-blinded, controlled trial

BACKGROUND

A more affordable pneumococcal conjugate vaccine (PCV) that provides comparable protection to current PCVs is needed to ensure sustainable access in resource-limited settings. Serum Institute of India Pvt. Ltd.'s PCV candidate (SIIPL-PCV) has the potential to meet this need as manufacturing efficiency has been optimized and the vaccine targets the most prevalent disease-causing serotypes in Africa and Asia. We report SIIPL-PCV's safety, tolerability, and immunogenicity in adults, toddlers, and infants in The Gambia.

METHODS

This phase 1/2, randomized, double-blind trial sequentially enrolled 34 PCV-naive adults (18-40 years old), 112 PCV (Prevenar 13® [PCV13])-primed toddlers (12-15 months old), and 200 PCV-naive infants (6-8 weeks old), who were randomized (1:1) to receive SIIPL-PCV or a licensed comparator vaccine. Infants received three-doses of SIIPL-PCV or PCV13 at 6, 10, and 14 weeks of age co-administered with routine Expanded Program on Immunization (EPI) vaccines. Reactogenicity was solicited through seven-days post-vaccination; unsolicited adverse events (AEs) were assessed throughout the study. The safety and immunogenicity of a matching booster at 10-14 months of age were evaluated in a subset of 96 infants. Immune responses were evaluated post-primary and pre- and post-booster vaccinations.

RESULTS

Reactogenicity was primarily mild-to-moderate in severity. In infants, the most common solicited reactions were injection-site tenderness and fever, with no meaningful treatment-group differences. There were no serious or severe vaccine-related AEs and no meaningful trends in SAEs, vaccine-related AEs, or overall AEs. Infant post-primary seroresponse rates (IgG level ≥ 0.35 µg/mL) were ≥89% for all serotypes except 6A (79%) in the SIIPL-PCV group. IgG GMCs were >1 µg/mL for all serotypes in both SIIPL-PCV and PCV13 groups. Post-booster GMCs were comparable between groups.

CONCLUSION

SIIPL-PCV was well-tolerated, had an acceptable safety profile, and was immunogenic for all vaccine serotypes. Results support the evaluation of SIIPL-PCV in a phase 3 non-inferiority trial. Clinicaltrials.gov: NCT02308540.

A Phase 2/3 double blinded, randomized, placebo-controlled study in healthy adult participants in Vietnam to examine the safety and immunogenicity of an inactivated whole virion, alum adjuvanted, A(H5N1) influenza vaccine (IVACFLU-A/H5N1)

BACKGROUND

A global shortfall of vaccines for avian influenza A(H5N1) would occur, especially in low- and-middle income countries, if a pandemic were to occur. To address this issue, development of a pre-pandemic influenza vaccine was initiated in 2012, leveraging a recently established influenza vaccine manufacturing capacity in Vietnam.

METHODS

This was a Phase 2/3, double-blinded, randomized, placebo-controlled study to test the safety and immunogenicity of IVACFLU-A/H5N1 vaccine in healthy adults. Phase 2 was a dose selection study, in which 300 participants were randomized to one of the three groups (15 mcg, 30 mcg, or placebo). Safety and immunogenicity were assessed in all participants. In Phase 3, 630 participants were randomized to receive the IVACFLU-A/H5N1 vaccine dose selected in Phase 2 (15 mcg, n = 525) or placebo (n = 105). Safety was assessed in all Phase 3 participants and immunogenicity was measured in a subset of participants.

RESULTS

The vaccine was well tolerated and most of the adverse events were mild and of short duration. Mild pain at the injection site was the most common adverse event seen in 60 percent of participants in the vaccine group in Phase 3. In Phase 2, both 15 mcg and 30 mcg doses were immunogenic, so the lower dose was selected for further testing in Phase 3. In Phase 3 overall seroconversion rates were 68 percent for hemagglutination inhibition (HI), 51 percent for microneutralization (MN) and 56 percent for single radial hemolysis (SRH). The seroprotection rates were 44 percent for HI, 41 percent for MN and 55 percent for SRH. The GMT ratio was 5.31 and 3.7 for HI and MN respectively; GMA was 4.75 for the SRH.

CONCLUSION

The IVACFLU A/H5N1 was safe and immunogenic. Development of this pandemic avian influenza vaccine is a welcome addition to the limited global pool of these vaccines. ClinicalTrials.gov register NCT02612909.

Quality of life in patients with multiple sclerosis and its association with depressive symptoms and physical disability

OBJECTIVE

The aim of this work was to evaluate the quality of life of patients with multiple sclerosis and its association with depressive symptoms and physical health.

METHOD

A total of 117 patients clinically diagnosed with Multiple Sclerosis (MS) were studied. The MSQOL-54 scale was applied. The depressive symptoms were assessed using the Beck Depression Inventory (BDI), while degree of physical disability was evaluated with the EDSS (Expanded Disability Status Scale). The results of these last two instruments were associated with MSQOL-54 to determine its influence on the perception of quality of life.

RESULTS

We evaluated 65 women (56%) and 52 men (44%), with a mean age of 35 years, a mean age of 27 years at the time of diagnosis, and a mean evolution of 8 years. 88% of the patients showed the relapsing-remitting subtype; 42% had paid employment; 29% of the studied patients required help to perform daily activities; 75% took disease-modifying medications. They obtained on average a score of 3.62 ± 2.30 on the EDSS and 11.5 ± 9.21 on the BDI. The general average in MSQOL-54 was 64.67 ± 17.52.

CONCLUSIONS

Quality of life, in patients with multiple sclerosis is an issue that worries health personnel, it is essential to implement strategies for reducing the impact of the disease on patients' lives, mainly through the application of programs aimed to decrees depression and improve social support.

A phase 2/3 double-blind, randomized, placebo-controlled study to evaluate the safety and immunogenicity of a seasonal trivalent inactivated split-virion influenza vaccine (IVACFLU-S) in healthy adults in Vietnam

Background: Under the WHO's Global Action Plan for influenza vaccines, we conducted a phase 2-3 study of IVACFLU-S, a trivalent, seasonal inactivated influenza vaccine candidate.Methods: In the phase 2 portion of the study, 252 participants received one dose of 15 mcg hemagglutinin (HA) vaccine per strain or placebo. Following determination of safety, 636 additional participants were randomized in phase 3 to receive vaccine or placebo. Immunogenicity was assessed in a subset of the participants in the phase 3 study.Results: Higher proportion (70%) of participants in the IVACFLU-S arm reported solicited local adverse events (AEs) (p < .0001) as compared to placebo (25%). Mild injection site pain and tenderness were most common AEs seen in 55% and 60% of participants in the vaccine group. The solicited systemic AEs were comparable (p = .4149). The majority of solicited and unsolicited AEs were mild to moderate in severity. In the vaccine arm for the combined age group of 18-60 years of age, seroconversion against antigens A/H1N1, A/H3N2, and B was achieved in 70.3%, 76.1%, and 54.1% of participants respectively; seroprotection against antigens A/H1N1, A/H3N2, and B was achieved in 83.3%, 86.6%, and 60.3% of participants respectively; and the geometric mean fold rise for the hemagglutinin-inhibition (HI) antibody titers against antigen A/H1N1, A/H3N2, and B were 13.15, 11.85, and 5.87, respectively.Conclusion: This study demonstrates the local reactogenicity, other safety, and immunogenicity of IVACFLU-S, first domestically produced influenza vaccine in Vietnam.ClinicalTrials.gov number NCT03095599 (March 29, 2017).

Composites of Anthraquinone Dyes@HKUST-1 with Tunable Microstructuring: Experimental and Theoretical Interaction Studies

The metal-organic framework (MOF) HKUST-1 was employed as an interaction matrix for fundamental loading studies of anthraquinone dyes. Chosen dyes were alizarin (A), alizarin S (AS), disperse blue 1 (B1), disperse blue 3 (B3), disperse blue 56 (B56) and purpurin (P). All materials were characterized by XRD, FTIR, TGA and SEM. Hence the interaction of dyes with the framework was characterized by theoretical-experimental differential analysis. One-pot loading strategy resulted in more efficient scavenging of dyes, and reached 100 % for B56 using 50 mg L^-1 . SEM revealed important microstructural changes, the smaller crystals ranged 0.8-3 μm in size and almost all composite sizes were from this to higher values, reaching 70 μm, with varying shapes. Two composites were larger in size range (about 2500-1000 μm), and were shaped as rods, octahedrons and coffin lids. Indeed, the microstructure could be modulated depending on preparation conditions and type of loaded dye. For the higher loading series, N₂ adsorption and XPS experiments were carried on to further evidence dye-MOF interactions. Ab initio prediction of structural properties for A@HKUST-1 and P@HKUST-1 were obtained by means of solid-state CRYSTAL14 code at the PBE0 level of theory. Computed findings evidenced two O→Cu coordinative bonds, one from O-ketone and the other from O-phenolate moiety as main interactions towards CuNET centers.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Improved DNA extraction technique from clot for the diagnosis of Chagas disease

Background

The detection of Trypanosoma cruzi genetic material in clinical samples is considered an important diagnostic tool for Chagas disease. We have previously demonstrated that PCR using clot samples yields greater sensitivity than either buffy coat or whole blood samples. However, phenol-chloroform DNA extraction from clot samples is difficult and toxic. The objective of the present study was to improve and develop a more sensitive method to recover parasite DNA from clot samples for the diagnosis of Chagas disease.

Methodology/Principal findings

A total of 265 match pair samples of whole blood–guanidine (GEB) and clot samples were analyzed; 150 were from Chagas seropositive subjects. DNA was extracted from both whole blood-guanidine samples, using a previously standardized methodology, and from clot samples, using a newly developed methodology based on a combination of the FastPrep technique and the standard method for GEB extraction. A qPCR targeting the nuclear satellite sequences was used to compare the sample source and the extraction method. Of the 150 samples from Chagas positive individuals by serology, 47 samples tested positive by qPCR with DNA extracted by both GEB and clot, but an additional 13 samples tested positive only in DNA extracted from clot. No serology-negative samples resulted positive when tested by qPCR.

Conclusions

The new methodology for DNA extraction from clot samples improves the molecular diagnosis of Chagas disease.

Detection of nucleic acid has become an important tool for the diagnosis of Chagas disease. Whole blood samples are usually the source of DNA and qPCR the preferred technique to demonstrate the presence of T. cruzi DNA. Although DNA extracted from clot samples has shown higher sensitivity than from whole blood, DNA extraction is performed using phenol-chloroform, which has biohazard issues. We theorize that a clot traps parasites, making it a better source of DNA for Chagas diagnosis using PCR. The present study describes a new DNA extraction methodology from clot samples which avoids the use of phenol-chloroform. The new methodology was compared to the internationally standardized diagnostic method, which is based on extraction of DNA from whole blood preserved with guanidine EDTA and a commercial kit.

Safety and immunogenicity of inactivated monovalent influenza A/H1N1 vaccine candidate manufactured in Vietnam

We tested a new A/H1N1 inactivated influenza vaccine (IIV) manufactured by Institute of Vaccines and Medical Biologics (IVAC), Vietnam in 48 adults in a Phase 1, double-blinded, randomized, placebo-controlled trial. Two doses of unadjuvanted vaccine or placebo were administered three weeks apart. The vaccine was well tolerated with only transient mild local reactions and low-grade fever in a small proportion of the subjects. One serious adverse event considered unrelated to the study product was reported. The IVAC vaccine proved to be highly immunogenic with 91 percent (95% CI: 0.78, 1) of the subjects developing a ≥4 fold immune responses by hemagglutination inhibition (HAI) assay, and 96 percent (95% CI: 0.78, 1) by the microneutralization (MN) assay. Post-vaccination geometric mean titers (GMTs) were 283.7 (95% CI: 161.7, 497.5) in the HAI and 725.7 (95% CI: 411.3, 1280.3) in the MN assay. These promising results merit further development of the vaccine. ClinicalTrials.gov number: NCT01507779.

A Phase III open-label, randomized, active controlled clinical study to assess safety, immunogenicity and lot-to-lot consistency of a bovine-human reassortant pentavalent rotavirus vaccine in Indian infants

BACKGROUND

A heat-stable bovine-human rotavirus reassortant pentavalent vaccine (BRV-PV, ROTASIIL®) was developed in India. In this study, the vaccine was tested for safety, immunogenicity and clinical lot-to-lot consistency.

METHODS

This was a Phase III, open label, randomized, equivalence design study. The primary objective was to demonstrate lot-to-lot consistency of BRV-PV. Subjects were randomized into four arms, three arms received Lots A, B, and C of BRV-PV and the control arm, received Rotarix®. Three doses of BRV-PV or two doses of Rotarix® and one dose of placebo were given at 6, 10, and 14 weeks of age. Blood samples were collected four weeks after the third dose to assess rotavirus IgA antibody levels. The three lots of BRV-PV were equivalent if the 95% Confidence Intervals (CIs) of the geometric mean concentration (GMC) ratios were between 0.5 and 2. Solicited reactions were collected by using diary cards.

RESULTS

The study was conducted in 1500 randomized infants, of which 1341 infants completed the study. The IgA GMC ratios among the three lots were around 1 (Lot A versus Lot B: 1.07; Lot A versus Lot C: 1.06; and Lot B versus Lot C: 0.99). The 95% CIs for the GMC ratios were between 0.78 and 1.36. The IgA GMCs were: BRV-PV group 19.16 (95% CI 17.37-21.14) and Rotarix® group 10.92 (95% CI 9.36-12.74) (GMC ratio 1.75; 90% CI 1.51-2.04). Seropositivity rates were 46.98% (95% CI 43.86-50.11) and 31.12% (95% CI 26.17-36.41). The incidence of solicited reactions was comparable across the four arms. No serious adverse events were associated with the study vaccines, except two gastroenteritis events in the BRV-PV groups.

CONCLUSION

Lot-to-lot consistency of BRV-PV was demonstrated in terms of GMC ratios of IgA antibodies. The vaccine safety and immunogenicity profiles were similar to those of Rotarix®. Clinical Trials.Gov [NCT02584816] and Clinical Trial Registry of India [CTRI/2015/07/006034].

Non-interference of Bovine-Human reassortant pentavalent rotavirus vaccine ROTASIIL® with the immunogenicity of infant vaccines in comparison with a licensed rotavirus vaccine

Background

A newly developed bovine-human reassortant pentavalent vaccine (BRV-PV, ROTASIIL®) was tested for its potential effect on the immunogenicity of concomitantly administered EPI vaccines in infants in a randomized controlled study in India.

Methods

In this Phase III, multicenter, open label, randomized, controlled study, three doses of BRV-PV or two doses of Rotarix® and one dose of placebo were given to healthy infants at 6, 10, and 14 weeks of age. Subjects also received three doses of DTwP-HepB-Hib (diphtheria, tetanus, whole-cell pertussis, hepatitis B, and haemophilus influenzae type b conjugate – pentavalent vaccine) and oral polio vaccine concomitantly at 6, 10, and 14 weeks of age and a single dose of inactivated polio vaccine at 14 weeks of age. Blood samples were collected four weeks after the final vaccination to assess immune responses to all the vaccines administered. For diphtheria, tetanus, hepatitis B, Hib, polio type 1, and polio type 3 antibodies, non-interference was to be supported if the lower limit of the two-sided 90% confidence interval (CI) for the seroprotection rate difference for the BRV-PV group minus the Rotarix® group was >10.0%. For pertussis antibodies, non-interference was to be supported if the lower limit of the two-sided 90% CI for the ratio of geometric mean concentrations (GMCs) was >0.5.

Results

A total of 1500 infants were randomized to either BRV-PV (1125 infants) or Rotarix® (375 infants), of which 1341 completed the study as per the protocol. More than 97% of subjects achieved seroprotective antibody titres against diphtheria, tetanus, hepatitis B, Hib, polio type 1, and polio type 3 in both groups. The difference in seroprotection rates between the BRV-PV group and the Rotarix® group for all these antibodies was less than 1%. The ratio of GMCs of anti-pertussis IgG concentrations for the BRV-PV group versus Rotarix® was 1.04 [90% CI: 0.90; 1.19].

Conclusion

BRV-PV does not interfere with the immunogenicity of concomitantly administered routine infants vaccines.

Impact of lower challenge doses of enterotoxigenic Escherichia coli on clinical outcome, intestinal colonization and immune responses in adult volunteers

A reliable and effective human challenge model is needed to help down-select the most promising ETEC vaccines currently under development. Such a model would need to reliably induce diarrhea in a high proportion of volunteers using the lowest possible inoculum to maximize safety and sensitivity. Previously we validated a challenge model that utilized a dose of 2x107 CFU of ETEC strain H10407 (LT+, ST+, CFA/I+ and O78+) to induce attack rates for moderate to severe diarrhea (MSD) of ~60-70%. Here we detail efforts to further refine the model in an attempt to determine if a lower challenge dose of H10407 can be used. Thirty subjects were randomized 1:1 to receive an oral administration of H10407 at doses of 106 or 105 CFU in bicarbonate buffer. After challenge, subjects were monitored for signs and symptoms of enteric illness and stool samples were collected to detect shedding of the challenge strain. Systemic and mucosal immune responses were measured using serum, antibody in lymphocyte supernatant and fecal samples. The attack rate was 13.3% (2/15) and 26.7% (4/15) for MSD in the 105 and 106 groups, respectively. Four MSD cases met criteria for early antibiotic treatment. All subjects but one shed the challenge strain in fecal samples. The frequency and magnitude of anti-LT toxin, CFA/I and LPS O78 immune responses were antigen, dose, severity of diarrhea and shedding levels dependent. Notably, although of lower magnitude, there were considerable immune responses in the subjects with no diarrhea. This may indicate that immune responses to asymptomatic infections of ETEC in children in the endemic countries may contribute to protection. Based on this and our prior studies, we conclude that a dose of 2x107 H10407 remains the lowest practical dose for use in future volunteer studies evaluating candidate vaccines and other preventive or therapeutic ETEC interventions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00844493.