Background: Three full doses of RTS,S/AS01 malaria vaccine provides partial protection against controlled human malaria parasite infection (CHMI) and natural exposure. Immunization regimens, including a delayed fractional third dose, were assessed for potential increased protection against malaria and immunologic responses.

Methods: In a phase 2a, controlled, open-label, study of healthy malaria-naive adults, 16 subjects vaccinated with a 0-, 1-, and 2-month full-dose regimen (012M) and 30 subjects who received a 0-, 1-, and 7-month regimen, including a fractional third dose (Fx017M), underwent CHMI 3 weeks after the last dose. Plasmablast heavy and light chain immunoglobulin messenger RNA sequencing and antibody avidity were evaluated. Protection against repeat CHMI was evaluated after 8 months.

Results: A total of 26 of 30 subjects in the Fx017M group (vaccine efficacy [VE], 86.7% [95% confidence interval [CI], 66.8%-94.6%]; P < .0001) and 10 of 16 in the 012M group (VE, 62.5% [95% CI, 29.4%-80.1%]; P = .0009) were protected against infection, and protection differed between schedules (P = .040, by the log rank test). The fractional dose boosting increased antibody somatic hypermutation and avidity and sustained high protection upon rechallenge.

Discussions: A delayed third fractional vaccine dose improved immunogenicity and protection against infection. Optimization of the RTS,S/AS01 immunization regimen may lead to improved approaches against malaria.

Clinical Trials Registration: NCT01857869.

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiw237DOI Listing

Publication Analysis

Top Keywords

fractional third
12
rtss/as01 malaria
8
phase controlled
8
controlled human
8
human malaria
8
malaria parasite
8
parasite infection
8
third dose
8
dose
6
protection
6

Similar Publications

A preliminary study was conducted using electronic portal imaging device (EPID) based dose verification in pre-treatment and in vivo dose reconstruction modes for breast cancer intensity-modulated radiation therapy (IMRT) technique with known repositioning set-up errors. For 43 IMRT plans, the set-up errors were determined from 43 sets of EPID images and 258 sets of cone beam computed tomography images. In-house developed Edose software was used to reconstruct the dose distribution using the pre-treatment and on-treatment (in vivo) EPID acquired fluence maps.

View Article and Find Full Text PDF

Background: Depressive symptoms are associated with reduced brain integrity. However, it is unclear if this association holds among a racially and ethnically diverse population aged ≥90 years and if there are differences by gender.

Method: The LifeAfter90 Study enrolled 212 long-term members of Kaiser Permanente Northern California who were ≥90 years old, without dementia diagnosis, and received neuroimaging via 3T MRI.

View Article and Find Full Text PDF

The two most extensively studied cannabinoids, cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), are used for myriad conditions. THC is predominantly eliminated via the cytochromes P450 (CYPs), whereas CBD is eliminated through both CYPs and UDP-glucuronosyltransferases (UGTs). The fractional contributions of these enzymes to cannabinoid metabolism have shown conflicting results among studies.

View Article and Find Full Text PDF

Background: Intravenous lipid emulsions are an essential component of nutritional support for very preterm infants. Many neonatal intensive care units have transitioned from traditional soybean oil-only to fish oil-containing multicomponent lipid emulsions, but the neurodevelopmental implications have not been well-explored. The primary aim of this study was to assess extrauterine third trimester brain growth in very preterm infants supported with soybean oil-only compared to fish-oil containing multicomponent lipid emulsions; white matter development and neurobehavioral regulation at term were also investigated.

View Article and Find Full Text PDF

Background: Few studies investigated the implications of post-PCI QFR and post-PCI ΔQFR (absolute increase of QFR) in de novo lesions of small coronary disease after drug-coated balloon (DCB).

Objectives: We sought to investigate the prognostic implications of post-PCI QFR and post-PCI ΔQFR in patients who received DCB only.

Methods: Patients were divided according to the optimal cutoff value of the post-PCI QFR and the post-PCI ΔQFR.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!