Oxford-led researchers develop a low-cost rapid test to identify heat-damaged vaccines
Researchers from Medicine Quality Research Group, the University of Oxford and their collaborators have developed and evaluated a novel low-cost, rapid method to identify heat-exposed sucrose-containing vaccines without the need for sophisticated laboratory equipment.
The method, published in the International Journal of Pharmaceutics, could help protect vaccine effectiveness, particularly in low-resource settings where maintaining cold-chain conditions during transport and storage can be challenging.
Vaccines must be kept within strict temperature limits to remain stable and effective. If cold-chain conditions are not maintained, vaccines may be exposed to heat, leading to a loss of potency and reduced protection. While vaccine efficacy can be assessed using biological potency assays, these tests are complex, expensive, time-consuming and require specialist laboratories, instruments and trained personnel.
The Vaccine Identity Evaluation (VIE) Consortium, led by Professor Paul Newton, Head of Medicine Quality Research Group, evaluated a novel screening test to detect heat exposure in sucrose-containing vaccines. Sucrose, commonly known as table sugar, breaks down when exposed to heat into glucose and fructose. The VIE team demonstrated that simple glucose assays can be used to identify heat-exposed vaccines, and that glucose concentration correlates with loss of vaccine potency.
The approach is intended as a screening tool and is not designed to replace established potency assays. Instead, it provides a rapid, low-cost way to support inspectors and regulators in selecting samples for further investigation. The assay would be particularly beneficial in low-resource settings to help monitor the integrity of the vaccine cold chain.
Professor Newton, of the Centre for Tropical Medicine and Global Health, University of Oxford, said: “There has been little research as to how to detect heat degraded vaccines in supply chains and this discovery and the potential simplicity of its implementation, for at least some vaccines, holds promise for screening for vaccines affected by heat.”
Study co-lead, Dr Bevin Gangadharan of the Department of Biochemistry and Kavli Institute for Nanoscience Discovery, University of Oxford, said: “Our simplest assay involves mixing the vaccine with a reagent, incubating this mixture in an oven for 30 minutes and then visually looking for a colour change to pink. This is the first simple and rapid test of its kind and does not require any sophisticated devices.”
Study co-lead, Professor Nicole Zitzmann, of the Department of Biochemistry and Kavli Institute for Nanoscience Discovery, University of Oxford, said: “By translating a simple chemical change into a practical screening tool, this work demonstrates how accessible science can address real challenges in vaccine supply chains. The assay offers a rapid, affordable way to flag potentially compromised vaccines and support decision-making, particularly in settings where laboratory resources are limited.”
The international consortium behind the study includes representatives from the University of Oxford’s Nuffield Department of Medicine, Department of Biochemistry, Kavli Institute for Nanoscience Discovery and Department of Chemistry; STFC, part of UK Research and Innovation (UKRI); the John Radcliffe Hospital; the University of East London; the World Health Organization (WHO), Geneva; the Serum Institute of India; and Agilent Technologies.
Read the paper: Ensuring vaccine cold chain integrity: A rapid and low-cost test for identifying heat-exposed sucrose-containing vaccines
About VIE
The Vaccine Identity Evaluation (VIE) Consortium has also been evaluating novel techniques for detecting falsified vaccines in supply chains. They have successfully used spatially-offset Raman spectroscopy, rapid diagnostic tests, and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry to differentiate genuine vaccines from falsified vaccine surrogates.