A bivalent pneumococcal histidine triad protein D-choline-binding protein A vaccine elicits functional antibodies that passively protect mice from Streptococcus pneumoniae challenge.

Vaccines based on conserved pneumococcal proteins are being investigated because serotype coverage by pneumococcal polysaccharide and polysaccharide conjugate vaccines is incomplete and may eventually decrease due to serotype replacement. Here, we examined the functionality of human antibodies induced by a candidate bivalent choline-binding protein A- pneumococcal histidine triad protein D (PcpA-PhtD) vaccine. Pre- and post-immune sera from subjects who had been vaccinated with the PcpA-PhtD candidate vaccine were tested in an established passive protection model in which mice were challenged by intravenous injection with Streptococcus pneumoniae serotype 3 strain A66.

Safety and immunogenicity of a trivalent recombinant PcpA, PhtD, and PlyD1 pneumococcal protein vaccine in adults, toddlers, and infants: A phase I randomized controlled study.

Background: Pneumococcal protein vaccines (PPrVs) may provide improved protection over currently available polysaccharide and conjugated polysaccharide vaccines. Here, we examined the safety and immunogenicity of a trivalent recombinant PPrV containing PcpA, PhtD, and PlyD1.

Methods: This was a phase I, single-center, randomized, observer-blind study with safety review between cohorts.

Passive protection of mice against Streptococcus pneumoniae challenge by naturally occurring and vaccine-induced human anti-PhtD antibodies.

Currently marketed Streptococcus pneumoniae vaccines are based on polysaccharide capsular antigens from the most common strains. Pneumococcal histidine triad protein D (PhtD) is a conserved surface protein that is being evaluated as a candidate for a vaccine with improved serotype coverage. Here, we measured the functional activity of human anti-PhtD antibodies in a passive protection model wherein mice were challenged with a lethal dose of S.

Safety and immunogenicity of the pneumococcal pneumolysin derivative PlyD1 in a single-antigen protein vaccine candidate in adults.

Background: Pneumococcal vaccines based on conserved protein antigens have the potential to offer expanded protection against Streptococcus pneumoniae.

Objective: This study examined the safety and immunogenicity in adults of three doses of a pneumococcal single-antigen protein vaccine candidate formulated with aluminum hydroxide adjuvant and recombinantly derived, highly detoxified, genetically mutated pneumolysin protein (PlyD1).

Methods: This phase I, randomized, placebo-controlled, observer-blinded, dose-escalating study enrolled adults (18-50 years).

Safety and immunogenicity of pneumococcal protein vaccine candidates: monovalent choline-binding protein A (PcpA) vaccine and bivalent PcpA-pneumococcal histidine triad protein D vaccine.

Background: Pneumococcal vaccines based on protein antigens may provide expanded protection against Streptococcus pneumoniae.

Objective: To evaluate safety and immunogenicity in adults of pneumococcal vaccine candidates comprising S. pneumoniae pneumococcal histidine triad protein D (PhtD) and pneumococcal choline-binding protein A (PcpA) in monovalent and bivalent formulations.