Assessing vaccine cold chain storage and transport in Ukraine: a cross-sectional study

Background: This study aimed to monitor risks of temperature excursions along vaccine distribution routes in Ukraine to identify weaknesses and recommend improvements. Methods: This cross-sectional study followed the World Health Organization’s temperature monitoring protocol. Vaccine shipments along randomly selected distribution routes were monitored using loggers, recording temperatures at 20 minutes intervals across all levels of the cold chain. The collected data were analysed to assess compliance with the recommended range and identify instances of heat and freeze exposure. Results : A total of 72040.1 hours were recorded from July 2024 to October 2024 across 48 distribution routes. The recorded temperature ranged from -13.6 ^o C to +28.4 ^o C. The level of compliance with the recommended temperature range varied by immunisation supply chain level and across facilities at a given level. The highest compliance (~100%) was observed at national and oblast stores and during transits between these levels. At the same time, the lowest compliance (88.8%) during storage was observed at primary healthcare centre (PHC) sub-offices, with three of such facilities failing to maintain the recommended range at any point during the study. Additionally, 20 freeze and five heat alarms were recorded at this level, indicative of prolonged exposures. During transits to PHC and sub-offices, compliance was achieved during 54.8% and 60.3% of the recorded time, respectively. Furthermore, eight transits to PHC and 15 to PHC sub-offices failed to maintain temperatures within the required range throughout the transit. Conclusions: While Ukraine’s vaccine cold chain system is effective at higher levels, temperature excursions were common at lower levels, particularly in PHC sub-offices and during transport to lower-level facilities. Equipment malfunctions, gaps in knowledge and lack of procedures, compounded by power outages and lack of power supply contingencies, are probable causes. Systematically identifying and documenting temperature excursions and assessing the potential damage to vaccines are recommended immediate actions. Providing further qualified equipment, ensuring resilient power supply, strengthening training, and improving procedures and supervision to prevent and mitigate risks of temperature excursion incidents are longer-term recommended actions. Implementing these actions would strengthen Ukraine’s immunisation supply chain resilience, ensuring safe and effective immunisation services.