Key result
Manufacturer-specific in vitro relative potency methods for EV71 vaccines were established, showing strong correlation with in vivo results (r > 0.99, P < 0.01).
Why the study?
Commercial EV71 inactivated vaccines rely on variable in vivo potency tests for batch release, prompting the development of in vitro relative potency methods aligned with 3R principles.
Effect estimate: r > 0.99
p-value: p=< 0.01
In vitro relative potency methods provide a reliable, animal-free alternative for EV71 vaccine batch release.
May enable 3R-compliant potency testing for EV71 vaccines; leaves open regulatory adoption pending validation.
BACKGROUND: The three commercial Enterovirus 71 (EV71) inactivated vaccines which have effectively controlled the EV71 pandemic currently rely on inherent variable in vivo potency methods for batch release. To align with 3R (Replacement, Reduction, Refinement) principles and enhance quality control, this study referred to WHO guidelines and the European Pharmacopoeia to develop in vitro relative potency (IVRP) methods. METHODS: Working standards tracing to phase 3 clinical vaccines were established. Manufacture-specific IVRP methods were developed and validated per ICH Q14/Q2(R2), utilizing conformational epitope-targeting neutralizing monoclonal antibodies (MAbs). One of the MAbs (CT11F9) recognition sites was clarified with Cryo-EM. Subsequently, the performance of IVRP was assessed using varied concentrations and heat-treated vaccines. The correlation between IVRP and in vivo methods was analyzed, followed by setting IVRP specifications. RESULTS: < 0.01, r > 0.99) and indicate the stability of the vaccines. Cryo-EM was adopted to identify the epitopes recognized by CT11F9, revealing that this neutralizing antibody recognizes a conformational epitope spanning VP1-3 of the same protomer. Using 31-47 batches of commercial vaccines, IVRP specifications were proposed as 0.56-1.35, 0.58-1.40, and 0.54-1.50. CONCLUSIONS: Based on conformational epitope-targeting neutralizing MAbs, manufacturer-specific IVRP methods, which were sensitive to process variations and correlated with in vivo results, have been established. IVRP methods provide a reliable, animal-free alternative for EV71 vaccine batch release.
No takes yet. Share an insight, caveat, or question.
Zhang et al. (2025) studied Enterovirus 71 (EV71) inactivated vaccine. In vitro relative potency (IVRP) methods vs. In vivo potency methods was evaluated on Correlation between IVRP and in vivo methods (r > 0.99, p=< 0.01). Manufacturer-specific in vitro relative potency methods for EV71 vaccines were established, showing strong correlation with in vivo results (r > 0.99, P < 0.01).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: