Evaluating Stability-indicating Characteristics of Alternative Potency Assays for Inactivated Influenza Vaccine

Emily Patel^*
*Correspondence: Emily Patel, Department of Immunology, Public University in Memphis, Tennesse, TN 38152, USA, Email:

Introduction

The development and evaluation of potency assays for vaccines are critical steps in ensuring their efficacy and safety. In the case of inactivated influenza vaccines, which are widely used to prevent seasonal influenza infections, potency assays play a pivotal role in determining the amount of antigenic material present in each vaccine dose. This quantitative assessment is essential for batch release and regulatory approval, as it verifies that the vaccine meets potency requirements necessary to induce protective immune responses in vaccinated individuals. Traditional potency assays for inactivated influenza vaccines typically involve measuring the antigen content through methods such as Single Radial Immunodiffusion (SRID) or Enzyme-Linked Immunosorbent Assay (ELISA). These assays are well-established and provide reliable measurements of antigen concentration based on antibody-antigen interactions. However, they may have limitations, including complexity, variability, and the requirement for specialized reagents and expertise. As a result, there is ongoing interest in developing alternative potency assays that offer improved reliability, sensitivity, and feasibility for routine vaccine testing and quality control [1].

Description

The evaluation of stability-indicating characteristics begins with the selection and development of alternative potency assays tailored to the specific attributes of inactivated influenza vaccines. These assays may employ different principles compared to traditional methods, aiming to improve sensitivity, specificity, and robustness in measuring vaccine potency. For instance, novel analytical platforms such as Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) offer the advantage of direct quantification of vaccine antigens based on precise molecular measurements. This approach not only enhances accuracy but also provides insights into antigenic integrity and stability. In addition to mass spectrometry-based assays, molecular biology techniques such as quantitative Polymerase Chain Reaction (qPCR) or bioassays utilizing cell-based systems are explored as alternative potency assays. These methods can detect and quantify specific viral components or biological activities relevant to vaccine potency, offering complementary insights into vaccine stability and efficacy. By diversifying the toolkit of potency assays, researchers aim to overcome the limitations of traditional assays while ensuring robust performance across different influenza vaccine formulations and variants [2].

The validation of stability-indicating characteristics involves rigorous testing of alternative potency assays under controlled conditions that mimic real-world scenarios encountered during vaccine production and distribution. Stability studies assess the assay's ability to accurately measure antigenic content over time and under varying storage temperatures, humidity levels, and other environmental factors. These studies provide critical data on the assay's sensitivity to detect changes in vaccine potency and its reproducibility across different batches and formulations. Moreover, stability-indicating studies evaluate the comparability of results obtained from alternative potency assays with those from traditional reference methods such as SRID or ELISA. This comparative analysis ensures that the alternative assays maintain consistency and reliability in measuring vaccine potency, thereby supporting their adoption for routine quality control and batch release testing. By establishing robust stability-indicating characteristics, alternative potency assays contribute to the overall assurance of vaccine quality and efficacy throughout the vaccine lifecycle [3-5].

Conclusion

In conclusion, the evaluation of stability-indicating characteristics of alternative potency assays for inactivated influenza vaccines represents a critical endeavor in vaccine development and quality assurance. Traditional potency assays have long served as the cornerstone for assessing vaccine antigenicity but may face challenges related to complexity, variability, and resource requirements. The quest for alternative potency assays seeks to address these challenges by harnessing innovative technologies that offer enhanced sensitivity, specificity, and feasibility for routine vaccine testing. Alternative potency assays, including mass spectrometry-based methods, molecular biology techniques, and bioassays, present promising opportunities to advance vaccine potency assessment. These assays leverage diverse analytical principles to measure vaccine antigens directly or through surrogate markers of biological activity, providing comprehensive insights into vaccine stability and efficacy. By evaluating stability-indicating properties, researchers validate the reliability of these assays to accurately detect changes in vaccine antigenicity over time and under varying environmental conditions.

Acknowledgement

None.

Conflict of Interest

None.

References

1. Sellies, Anne Jasmijn, Mirjam J. Knol, Hester E. de Melker and Patricia CJL Bruijning-Verhagen, et al. "Non-specific effects of the inactivated influenza vaccine. A test-negative study: The inactivated influenza vaccine and SARS-CoV-2 infections." Vaccine 42 (2024): 3455-3460.

   Google Scholar, Crossref, Indexed at

2. Zhang, Yang, Depeng Wang, Daotong Tan and Anqi Zou, et al. "Immune-enhancing activity of compound polysaccharide on the inactivated influenza vaccine." Carbohydr Polym 336 (2024): 122080.

   Google Scholar, Crossref, Indexed at

3. Alizadeh, Mohammadali, Sugandha Raj, Bahram Shojadoost and Ayumi Matsuyama-Kato, et al. "In ovo administration of retinoic acid enhances cell-mediated immune responses against an inactivated H9N2 avian influenza virus vaccine." Vaccine 41 (2023): 7281-7289.

   Google Scholar, Crossref, Indexed at

4. Engelhardt, Othmar G., Chantal Edge, Una Dunleavy, Kate Guilfoyle, et al. "Comparison of single radial immunodiffusion, SDS-PAGE and HPLC potency assays for inactivated influenza vaccines shows differences in ability to predict immunogenicity of haemagglutinin antigen." Vaccine 36 (2018): 4339-4345.

   Google Scholar, Crossref, Indexed at

5.  Vanni, Tazio, Maria da Graça Salomão, Juliana Yukari Kodaira Viscondi and Patrícia Emilia Braga, et al. "A randomized, double-blind, non-inferiority trial comparing the immunogenicity and safety of two seasonal inactivated influenza vaccines in adults." Vaccine 41 (2023): 3454-3460.

   Google Scholar, Crossref, Indexed at