June 6-11, 2010
Improving the stability of vaccines and removing vaccines from refrigerated storage for all or part of their shelf life have been proposed as strategies to help ensure vaccine effectiveness and to mitigate cold chain storage capacity constraints and escalating costs associated with the introduction of new vaccines into developing countries. Over the last six years, PATH has conducted research on stabilization of measles, Haemophilus influenzae type b (Hib), hepatitis B, enterotoxgenic Escherichia coli, conjugate meningococcal A, and pentavalent (Diphtheria-Tetanus-Pertussis-hepatitis B-Hib) vaccines in collaboration with 22 technical partners and 10 vaccine development groups. Results will be shared and include marked improvement to the stability of hepatitis B vaccine (12 months at 37 degrees C), more modest improvement to the stability of measles vaccine (8 weeks at 37 degrees C), and development of a freeze-protection method applicable to all aluminum adjuvant-containing vaccines.
Improved vaccine stability has an inherent value to manufacturers (e.g., improved bulk production efficiencies, reduced risk of recalls when the cold chain is breached during shipment, and reduced shipping and storage costs). Regardless, a return on investment for vaccine producers serving the highly price-sensitive developing-country markets is likely to be very dependent on the willingness of the customers to bear additional cost of goods. Mechanisms are needed to communicate desired stability profiles for new vaccines to vaccine developers and to incentivize vaccine developers to enhance product stability. In addition, dialogue between industry and the public sector (e.g., via the Vaccine Presentation and Packaging Advisory Group) is needed to analyze the inevitable trade-offs that occur between one desirable product attribute and another during product development.
Economic analyses of the incremental health and programmatic cost impacts of introducing four thermostable vaccines into immunization programs in Cambodia, Ghana, and Bangladesh show the potential for thermostable formulations to be cost-effective in low-resource settings. In addition, real efforts are underway through Project Optimize, a collaborative effort between the World Health Organization and PATH, to determine how vaccines can best be stored and distributed in the future. Project Optimize is seeking to answer the logistical, policy, regulatory, and cost issues related to labeling and storage of thermostable vaccines at controlled ambient temperatures for part of their shelf life to enable outreach and minimize storage/transport costs. This work will be critical to understanding the full value of thermostable vaccines.
Ray Cummings, Debra Kristensen, Dexiang Chen, and Michel Zaffran, "VACCINE STABILIZATION – RESEARCH, COMMERCIALIZATION, AND IMPACT" in "Vaccine Technology III", John G. Auniņš,Merck, USA; Barry C. Buckland, BiologicB, USA; Kathrin U. Jansen, Pfizer, USA; Paula Marques Alves, IBET, Portugal Eds, ECI Symposium Series, (2010). http://dc.engconfintl.org/vaccine_iii/18