Development of multidose thermotolerant formulations of a vector-based Covid-19 vaccine candidate, NDV-HXP-S in different product formats: Stability and preservative efficacy study.

Current lead coronavirus vaccines require continuous cold or ultra-cold storage from the manufacturing site to the field to maintain protective efficacy. Since cold chain capacity is limited and complex, logistics planning is crucial to limit vaccine wastage.[1] The restrictive storage concerns also make it difficult to share vaccines between public health departments and neighboring states, leading to increased vaccine wastage.

Development of a quantitative ELISA for SARS-CoV-2 vaccine candidate, NDV-HXP-S, with CpG 1018® adjuvant.

NDV-HXP-S is a Newcastle disease virus (NDV) vectored vaccine candidate which expresses the S-antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This vaccine candidate is under evaluation in human clinical studies with and without cytosine phosphate guanine (CpG) 1018® adjuvant. Existing potency methods for NDV-HXP-S do not allow for quantification of the S-antigen when the adjuvant is present.

The 2022 Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference: Summary of abstract-based presentations.

The global nonprofit organization PATH hosted the third Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference in Washington, DC, on November 29 to December 1, 2022. With a combination of plenary sessions and posters, keynote presentations, and breakout workshops, the 2022 VASE Conference featured key updates on research related to the development of vaccines against neglected diarrheal pathogens including Shigella, enterotoxigenic Escherichia coli (ETEC), Campylobacter, and Salmonella. The presentations and discussions highlighted the significant impact of these diarrheal pathogens, particularly on the health of infants and young children in low- and middle-income countries, reflecting the urgent need for the development and licensure of new enteric vaccines.

Route and antigen shape immunity to dmLT-adjuvanted vaccines to a greater extent than biochemical stress or formulation excipients.

A key aspect to vaccine efficacy is formulation stability. Biochemical evaluations provide information on optimal compositions or thermal stability but are routinely validated by ex vivo analysis and not efficacy in animal models. Here we assessed formulations identified to improve or reduce stability of the mucosal adjuvant dmLT being investigated in polio and enterotoxigenic E.

Identifying a stable bulk dmLT adjuvant formulation at a clinically relevant concentration.

Double mutant heat-labile toxin (dmLT) is a novel vaccine adjuvant under development with several different vaccine candidates. Studies using existing dmLT adjuvant stocks require significant dilution to achieve a clinically relevant dose. This dilution leads to wastage of the adjuvant.

Concordance of in vitro and in vivo measures of non-replicating rotavirus vaccine potency.

Rotavirus infections remain a leading cause of morbidity and mortality among infants residing in low- and middle-income countries. To address the large need for protection from this vaccine-preventable disease we are developing a trivalent subunit rotavirus vaccine which is currently being evaluated in a multinational Phase 3 clinical trial for prevention of serious rotavirus gastroenteritis. Currently, there are no universally accepted in vivo or in vitro models that allow for correlation of field efficacy to an immune response against serious rotavirus gastroenteritis.

Assessing the potency and immunogenicity of inactivated poliovirus vaccine after exposure to freezing temperatures.

According to manufacturers, inactivated poliovirus vaccines (IPVs) are freeze sensitive and require storage between 2°C and 8°C, whereas oral poliovirus vaccine requires storage at -20 °C. Introducing IPV into ongoing immunization services might result in accidental exposure to freezing temperatures and potential loss of vaccine potency. To better understand the effect of freezing IPVs, samples of single-dose vaccine vials from Statens Serum Institut (VeroPol) and multi-dose vaccine vials from Sanofi Pasteur (IPOL) were exposed to freezing temperatures mimicking what a vaccine vial might encounter in the field.

Heat-stable sublingual oxytocin tablets as a potential needle-free approach for preventing postpartum hemorrhage in low-resource settings.

Postpartum hemorrhage is a major cause of mortality and morbidity related to childbirth in developing countries. The recommended treatment includes administration of oxytocin; however, oxytocin is a heat-labile protein, and it must be given as an intramuscular injection by skilled health care providers. To address these challenges, we developed a freeze-dried oxytocin fast-dissolving tablet (FDT) for sublingual (SL) needle-free administration.

Preformulation studies with the Escherichia coli double mutant heat-labile toxin adjuvant for use in an oral vaccine.

Double mutant heat-labile toxin (dmLT) is a promising adjuvant for oral vaccine administration. The aims of our study were to develop sensitive methods to detect low concentrations of dmLT and to use the assays in preformulation studies to determine whether dmLT remains stable under conditions encountered by an oral vaccine. We developed a sandwich ELISA specific for intact dmLT and a sensitive SDS-PAGE densitometry method, and tested stability of dmLT in glass and plastic containers, in saliva, at the pH of stomach fluid, and in high-osmolarity buffers.

Developing a Flexible Pediatric Dosage Form for Antiretroviral Therapy: A Fast-Dissolving Tablet.

Current presentations of the anti-HIV drugs lopinavir and ritonavir make appropriate dosing for children difficult. We conducted a feasibility study to develop a formulation for these drugs with child-safe excipients in a flexible dosage form for children across the pediatric age spectrum. The freeze-drying in blister approach was used to produce fast-dissolving tablets (FDTs), as these can be dispersed in fluids for easy administration, even to infants, and appropriate portions of the dispersion can be given for different ages/weights.

Development of a Freeze-Dried, Heat-Stable Influenza Subunit Vaccine Formulation.

An influenza pandemic remains a major public health concern. A key strategy to prevent a pandemic is to stockpile and pre-position stable influenza vaccine to allow rapid deployment in response to an outbreak. However, most influenza vaccines today are formulated as liquids that are stable only within a temperature range of 2°C to 8°C and require use of a cold chain, making vaccine transportation, distribution, and storage complicated and expensive, particularly for developing countries.

Development of a stable liquid formulation of live attenuated influenza vaccine.

Vaccination is the most effective means of preventing influenza. However, the cost of producing annual seasonal influenza vaccines puts them out of reach for most developing countries. While live attenuated influenza vaccines are among the most efficacious and can be manufactured at low cost, they may require lyophilization to be stable enough for developing-country use, which adds a significant cost burden.

Methodology for preservation of yeast-bound single chain fragment variable antibody affinity reagents.

Readily accessible affinity reagents are critical to the validation of biomarkers and to the development of new diagnostic tests. As alternatives to monoclonal antibodies, yeast-bound single chain fragment variable antibody (yeast-scFv) can be rapidly selected from yeast display libraries. An important characteristic for any diagnostic reagent is its stability or ability to store it.

Structure-based analysis of the beta8 interactive sequence of human alphaB crystallin.

The functional importance of the beta8 sequence ((131)LTITSSLS(138)), which is on the surface of the alpha crystallin core domain of human alphaB crystallin, was evaluated using site-directed mutagenesis. Ultraviolet circular dichroism determined that mutating the surface-exposed, nonconserved residues, Leu-131, Thr-132, Thr-134, Ser-135, Ser-136, and Ser-138 individually or in combination (alphaAbeta8 and CEbeta8), had no measurable effect on secondary and tertiary structure. Size exclusion chromatography determined the size of the complexes formed by the beta8 mutants to be 6-8 subunits larger than wt alphaB crystallin.

The function of the beta3 interactive domain in the small heat shock protein and molecular chaperone, human alphaB crystallin.

Knowledge of the interactive domains on the surface of small heat shock proteins (sHSPs) is necessary for understanding the assembly of complexes and the activity as molecular chaperones. The primary sequences of 26 sHSP molecular chaperones were aligned and compared. In the interactive beta3 sequence, 73DRFSVNLDVKHFS85 of human alphaB crystallin, Ser-76, Asn-78, Lys-82, and His-83 were identified as nonconserved residues on the exposed surface of the alpha crystallin core domain.

Interactive domains for chaperone activity in the small heat shock protein, human alphaB crystallin.

Protein pin arrays identified seven interactive sequences for chaperone activity in human alphaB crystallin using natural lens proteins, beta(H) crystallin and gammaD crystallin, and in vitro chaperone target proteins, alcohol dehydrogenase and citrate synthase. The N-terminal domain contained two interactive sequences, (9)WIRRPFFPFHSP(20) and (43)SLSPFYLRPPSFLRAP(58). The alpha crystallin core domain contained four interactive sequences, (75)FSVNLDVK(82) (beta3), (113)FISREFHR(120), (131)LTITSSLS(138) (beta8), and (141)GVLTVNGP(148) (beta9).

Imaging linear birefringence and dichroism in cerebral amyloid pathologies.

New advances in polarized light microscopy were used to image Congo red-stained cerebral amyloidosis in sharp relief. The rotating-polarizer method was used to separate the optical effects of transmission, linear birefringence, extinction, linear dichroism, and orientation of the electric dipole transition moments and to display them as false-color maps. These effects are typically convolved in an ordinary polarized light microscope.