Safety and Immunogenicity of Respiratory Syncytial Virus Pre-fusion Maternal Vaccine Co-administered with Diphtheria-Tetanus-Pertussis Vaccine: A Phase 2 Study

BACKGROUND

Respiratory syncytial virus (RSV) fusion protein stabilized in the prefusion conformation (RSVPreF3) was under investigation as a maternal vaccine.

METHODS

This phase 2, randomized, placebo-controlled, single-dose, multicenter study enrolled healthy, non-pregnant women, randomized 1:1:1:1:1 to five parallel groups studying RSVPreF3 (60 or 120 µg) co-administered with diphtheria, tetanus, and acellular pertussis vaccine (dTpa) or placebo, and dTpa co-administered with placebo. Safety and humoral immune responses were assessed. An extension phase also assessed a RSVPreF3 120 μg vaccination 12-18 months post-first vaccination.

RESULTS

The safety profile of RSVPreF3 was unaffected by dose or dTpa co-administration. Solicited and unsolicited adverse events (AEs) were evenly distributed across study groups. Injection-site pain was higher following the second vaccination vs the first vaccination. Medically attended AEs were rare (<5% overall). Both RSVPreF3 dose levels (alone and with dTpa) were immunogenic, increasing levels of RSV-A neutralizing antibody ≥8 fold and anti-RSVPreF3 IgG antibody ≥11 fold at 1 month post-vaccination, which persisted at 12-18 months post-vaccination; modest 2-fold increases were observed with a second RSVPreF3 vaccination.

CONCLUSIONS

This study indicates RSVPreF3 co-administration with dTpa induces robust immune responses and is well tolerated, regardless of the RSVPreF3 dose level used.

CLINICAL TRIALS REGISTRATION

NCT04138056.

Chemical, physical, and biochemical concepts in isolation and purification of proteins

In this chapter the physicochemical basis of protein retention in adsorption chromatography has been examined. It is evident from this treatment that significant developments are in process with regard to both the theory and practice of high-resolution chromatographic methods, particularly at the preparative level with adsorptive stationary phases. The recognition that most purification strategies must be based on multidimensional multistage procedures presents numerous challenges for the protein chemist, the chromatographic scientist, and the biochemical engineer. The urgency for these developments has been stressed by the potential of modern biotechnology to produce large quantities of new proteins that must be obtained in highly purified form. The capabilities that these advances present will prove catalytic in the materials sciences as new solid phases are examined with particular properties for large-scale utilization. Similarly, new initiatives in protein engineering will lead to greater utilization of the fusion handle approach for selective protein isolation and recovery. The realization of these capabilities will represent an enthusiastic and innovative method that will revolutionize the role of bioprocess development over the next decade.

Comparative study of Zorbax Bio Series GF 250 and GF 450 and TSK-Gel 3000 SW and SWXL columns in size-exclusion chromatography of proteins

A reduction of the mean particle diameter of silica-based packings in the size-exclusion chromatography (SEC) of proteins to about 5 micron generates the expected increase in column plate number over the traditional 10 micron SEC columns, as demonstrated for the Zorbax Bio Series GF 250 and GF 450 and TSK-Gel 3000 SWXL columns. The slightly lower column efficiency of the TSK-Gel 3000 SWXL compared with the GF 250 column is compensated by the fact that the phase ratio of the 3000 SWXL column is higher by a factor of two. Hence both columns show nearly the same peak capacity of about 20-30. When the ionic strength of the eluent was changed by varying the salt concentration, the elution volume of proteins was found to be affected differently on the two columns. These alterations are attributed to the differences in the surface compositions of the two types of packings.

Separation of plasma membrane proteins of cultured human fibroblasts by affinity chromatography on bonded microparticulate silicas

Adsorbents for high-performance affinity chromatography were prepared by bonding proteins and reactive Procion triazine dyes to 3-isothiocyanatopropyl- and 3-aminopropylsilicas. The materials prepared were used successfully in the separation of hydrophobic plasma membrane proteins of cultured human fibroblasts. The data obtained show that the reaction of 3-isothiocyanatopropyltriethoxysilane (ITCPS) with the surface hydroxyl groups of silica yields a new and convenient route to preparing an "activated carrier" that is capable of coupling with potential affinity ligands containing amino functional groups. The reaction and bonding procedures of 3-isothiocyanatopropyltriethoxysilane and 3-aminopropyltriethoxysilane with silica were optimized with regard to a controlled and reproducible ligand density by adjusting the type of solvent and organic base as reaction catalyst. The ligand content of reactive triazine dyes directly coupled to 3-aminopropylsilica was significantly higher than that of the 6-aminohexyl derivatives coupled to 3-isothiocyanatopropylsilica. The stability of Procion Blue MX-R bonded to 3-aminopropylsilica and 3-isothiocyanatopropylsilica in phosphate-buffered aqueous solution at pH 5.0 and 8.0 was examined.

Optimum support properties for protein separations by high-performance size exclusion chromatography

Optimum chromatographic properties of high performance size exclusion chromatography (HPSEC) of proteins, such as resolution, molecular weight accuracy and recovery, are obtained on packings and columns with tailor-made physical and chemical structures, employed at properly adjusted eluent compositions and operation conditions. SEC-theory suggests that a broad molecular weight fractionation range and high linearity of the log-linear calibration plot can be achieved by the use of two packings (10- and 80-nm pore size, characterized by a pore-size distribution (psd) equal to or less than 1 decade and by equal internal column porosity (p)), rather than a single 30- to 50-nm pore-size packing with a wide psd. Favourably high-phase ratios of (p)/(o)/ 1.0 for HPSEC columns were accomplished with a minimum interstitial column porosity (o) and a high value for the internal column porosity (p) (the specific pore volume, nu(p), multiplied by the packing density, varrho(p).) Ligands such as diol, N-acetoxyamino and oligomeric ether with a propyl- or propoxy-spacer bonded to the silica at the highest density appear to provide high mass recovery and bioactivity as well as chemical stability. Such packings, available in 3-5 mum particle size ranges of narrow distribution, packed into columns 6 mm i.d. and 500 mm in length, offer the best compromise with respect to resolution, speed and pressure drop. More careful studies are required to explain the effects of protein conformational changes and interconversions during elution on HPSEC columns.