Thermostability of Vaccines in the Indian Context: A Review of Progress and Perspectives

Vaccine stability plays a crucial role in the effectiveness of immunization programs and is instrumental in preventing millions of deaths annually. To maintain the potency of vaccines, cold chain systems have been established for their proper storage and transportation, as exposure to unsuitable temperatures can significantly reduce vaccine efficacy. Aluminium-based compounds are commonly employed to enhance the thermal stability of vaccines. The formulation process is a vital phase in the development pipeline of new vaccines, encompassing approval, testing, and production. Despite advancements in stabilizing techniques, liquid formulations remain the preferred choice due to their simplicity in administration, packaging, and large-scale manufacturing. Nonetheless, several alternative strategies have been explored to improve thermostability. This review highlights various methods used to convert thermolabile vaccines into thermostable forms and discusses formulation strategies, including the incorporation of heat shock proteins such as mHSP70 and mHSP65, which play a role in enhancing both innate and adaptive immune responses.