By Mabel Izquierdo, Yassel Ramos, Lourdes Costa, Rodolfo Valdés, Yamila Martínez, Mónica Bequet-Romero, Vladimir Besada, Gerardo García, Galina Moya, Glay Chinea, Jennifer Rojas, José Marcelo, Ivan Andujar, Joaquín González, Mareysis Ruiz, Yurisleydis Aldama, Marta Ayala, Jorge Valdés, and Miladys Limonta
Volume 21, Open Access (September 2022)
From a regulatory standpoint, vaccine stability must be demonstrated, along with the prediction of stability during temperature excursions, before a vaccine can be approved for use in humans.
In this work, Abdala subunit vaccine thermostability was studied under thermal stress conditions (2–8°C [control], 25°C, 37°C, 45°C, and 60°C) for 15 days. Molecular integrity of the vaccine active pharmaceutical ingredient was monitored by SDS-PAGE, immunoblotting, RP-HPLC, mass spectrometry, and circular dichroism spectroscopy analysis. While functionality was monitored by immunogenicity assay, inhibition of binding between receptor-binding domain (RBD) and receptor, angiotensin converting enzyme 2 (ACE2), and RBD/ACE2 binding assay.
Results showed that no degradation, loss of disulfide bridges, nor modifications of secondary structure of the RBD molecule were detected at 25°C and 37°C. Moreover, high titers (1:48,853-1:427,849) of anti-RBD-specific mouse antibodies were detected with the ability to inhibit, to different degrees, the binding between RBD/ACE2.
In conclusion, the Abdala subunit vaccine is stable under thermal stress and storage conditions, which has an advantage over non-subunit vaccines previously approved or currently in development against COVID-19. The demonstrated high stability of this vaccine is a key factor in ensuring vaccine effectiveness, extending immunization coverage with fewer production runs, simplifying immunization logistics, and reducing cold chain-associated costs.
Citation:
Izquierdo M, Ramos Y, Costa L, Valdés R, Martínez Y, Bequet-Romero M, Besada V, García G, Moya G, Chinea G, Rojas J, Marcelo J, Andujar I, González J, Ruiz M, Aldama Y, Ayala M, Valdés J, Limonta M. BioProcess J, 2022; 21.
https://doi.org/10.12665/J21OA.Izquierdo
Posted online September 15, 2022.