Quality control of routine, experimental and real-time aged diphtheria toxoids by in vitro analytical techniques

In vitro innate immune cell based models to assess whole cell Bordetella pertussis vaccine quality: A proof of principle

“…In general, the use of alternative methods to replace existing animal models is strongly recommended and a range of physicochemical techniques is now available that can be used to characterise key aspects of vaccines [5,6]. However, these techniques do not assess vaccine-induced immune responses.…”

Biophysical comparison of diphtheria and tetanus toxins with the formaldehyde-detoxified toxoids, the main components of diphtheria and tetanus vaccines

“…The DSF analysis clearly demonstrated a highly increased thermal stability of the toxoids and was confirmed by thermal stability measurements using CD. Previous studies using protein fluorescence spectroscopy in combination with guanidine-HCl 15, 16 or differential scanning calorimetry 18 also confirm an increased stability of the toxoids compared with the toxins. However, to our knowledge, this is the first time DSF was applied in measuring a change in T m , used as surrogate parameter for protein stability, between toxins and toxoids.…”

“…14 For the in vitro characterization of diphtheria and tetanus vaccines, a combination of physico-chemical, immunochemical methods have previously been demonstrated as candidates for monitoring quality. [14][15][16][17][18][19] In the present study, we aim to use 2 novel methods for investigating and comparing the biophysical properties of diphtheria-and tetanus toxin with formaldehyde-inactivated toxoids. We apply differential scanning fluorimetry (DSF) to determine alterations in thermo-stability and small-angle X-ray scattering (SAXS) to obtain low-resolution structural information of the purified TeNT and DT and of the produced toxoids.…”

“…2D), with very close fits to the theoretical curve of the monomeric structure (x 2 D 1.04). As no structural data exist on the full-length TeNT, and to evaluate the scattering data, we generated a PHYRE2 16 homology model of TeNT (Fig. 3D) (Fig.…”

“…[27][28][29][30][31] Due to the economical and ethical burdens associated with animal experimentation, several studies have been dedicated to determine in vitro guidelines that could be used for monitoring the quality and potency of the vaccines and lead to reduction in the number of animals used for these tests. [14][15][16][17][18]32 Here, we used 2 novel methods to investigate the effect of formaldehyde detoxification on the thermal stability and structural integrity of TTd and DTd vaccine components produced and distributed by Statens Serum Institut. The DSF analysis clearly demonstrated a highly increased thermal stability of the toxoids and was confirmed by thermal stability measurements using CD.…”