ABSTRACT
Rotavirus A infection is a global leading cause of severe acute gastroenteritis associated with life-threatening diarrheal episodes in infants and young children. The disease burden is being reduced, namely due to a wider access to rotavirus vaccines. However, there is a demand to expand rotavirus vaccination programs, and to achieve this, it is critical to improve high-throughput in-process product quality control and vaccine manufacturing monitoring. Here, we present the development of an analytical method for the quantification of rotavirus particles contained in a licensed vaccine. The binding of rotavirus proteins to distinct glycoconjugate receptors and monoclonal antibodies was evaluated using biolayer interferometry analysis, applied on an Octet platform. The antibody strategy presented the best results with a linear response range within 2.5 × 107-1.0 × 108 particles·mL-1 and limits of detection and quantification of 2.5 × 106 and 7.5 × 106 particles·mL-1, respectively. Method suitability for the quantification of in-process samples was shown using samples from different manufacturing stages and their titers were comparable with the approved CCID(50) method. This cell-free method enables a fast and high-throughput analysis, compatible with time constraints during bioprocess development and it is suitable to be adapted to other viral particle-based drug products.
ABSTRACT
The immunogenicity and efficacy of ß-propiolactone (BPL) inactivated whole virion SARS-CoV (WI-SARS) vaccine was evaluated in BALB/c mice and golden Syrian hamsters. The vaccine preparation was tested with or without adjuvants. Adjuvant Systems AS01(B) and AS03(A) were selected and tested for their capacity to elicit high humoral and cellular immune responses to WI-SARS vaccine. We evaluated the effect of vaccine dose and each adjuvant on immunogenicity and efficacy in mice, and the effect of vaccine dose with or without the AS01(B) adjuvant on the immunogenicity and efficacy in hamsters. Efficacy was evaluated by challenge with wild-type virus at early and late time points (4 and 18 wk post-vaccination). A single dose of vaccine with or without adjuvant was poorly immunogenic in mice; a second dose resulted in a significant boost in antibody levels, even in the absence of adjuvant. The use of adjuvants resulted in higher antibody titers, with the AS01(B)-adjuvanted vaccine being slightly more immunogenic than the AS03(A)-adjuvanted vaccine. Two doses of WI-SARS with and without Adjuvant Systems were highly efficacious in mice. In hamsters, two doses of WI-SARS with and without AS01(B) were immunogenic, and two doses of 2 µg of WI-SARS with and without the adjuvant provided complete protection from early challenge. Although antibody titers had declined in all groups of vaccinated hamsters 18 wk after the second dose, the vaccinated hamsters were still partially protected from wild-type virus challenge. Vaccine with adjuvant provided better protection than non-adjuvanted WI-SARS vaccine at this later time point. Enhanced disease was not observed in the lungs or liver of hamsters following SARS-CoV challenge, regardless of the level of serum neutralizing antibodies.
