Scientists at PATH have developed a breakthrough formulation method that protects vaccines from the damaging effects of freezing temperatures, representing a critical step forward in ensuring the world’s children are receiving fully potent vaccines. Answers to the most frequently asked questions about this formulation method are below.
Why is PATH’s freeze-stable vaccine formulation method important?
World Health Organization (WHO) guidelines recommend that all vaccines (except oral polio vaccine) be stored at 2°C to 8°C. Maintaining these temperatures requires a vaccine cold chain: a global distribution network of equipment and procedures for maintaining vaccine quality (potency) during transport and storage in both developed and developing countries.
Research shows vaccines are frequently exposed to freezing temperatures across segments of the cold chain, rendering considerable vaccine damage and wastage. PATH’s breakthrough low-cost method for protecting specific vaccines from freeze damage is one answer to this problem. Resulting vaccines will be more effective and less vulnerable to freeze damage. Many vaccines are currently discarded when accidental freezing occurs. New freeze-stable vaccines will lower waste rates and help to save money for immunization programs.
Why develop the freeze-stable formulation method now?
WHO and many groups, including PATH, have worked for years to improve cold chain equipment and practices. After multicountry studies verified that accidental freezing of vaccines occurs at alarmingly high rates across segments of the cold chain, PATH scientists began to explore strategies for protecting vaccines from freeze damage.
What does the freeze-stable vaccine formulation method entail?
PATH scientists have addressed accidental freezing by adding specific stabilizers such as glycerin, polyethylene glycol 300, or propylene glycol, to vaccines containing aluminum adjuvants including hepatitis B, diphtheria, tetanus toxoid, and pertussis vaccines. The method was tested extensively in the laboratory at PATH and at the University of Colorado at Denver. Findings published in Vaccine (volume 27, issue 1) by PATH and our collaborators show that just a small amount of one of these stabilizers can protect vaccines containing aluminum adjuvants from the damage often caused by accidental freezing.
Does PATH’s freeze-stable formulation method involve “antifreeze”?
PATH's freeze-stable vaccine formulation method does not involve the use of antifreeze ingredients associated with combustible engines (e.g., cars). PATH’s method of freeze-protection involves stabilizers that are safe for humans and are in fact regularly used in sodas and generic shampoos, as well as oral and injectable medicines.
To date, PATH and collaborators have completed additional laboratory and preclinical studies validating the science and technology behind freeze-stable formulations. PATH has placed this technology in the public domain so that vaccine manufacturers worldwide can utilize the approach.
For more information on our innovative efforts to protect vaccines from freeze damage, see our overview of protecting aluminum-adjuvanted vaccines from freeze damage or contact Amy Wales at 206.285.3500 or firstname.lastname@example.org.