Use of cool water packs to prevent freezing during vaccine transportation at the country level.
OBJECTIVE
To study the impact of the use of cool water packs (water packs refrigerated at 2 to 8 degrees C) on the cold life of vaccine transport boxes and the shelf life of the vaccines.


METHODS
Data loggers were used to measure the temperatures of vaccine shipments with cool water packs in laboratory studies and country evaluations. The temperature recordings were mathematically translated into reduction of vaccines shelf life, which are illustrated through degrees of color changes of Vaccine Vial Monitors.


RESULTS
Laboratory studies at extreme ambient temperatures (43 degrees C) showed that, with the use of cool water packs, temperatures inside the cold box rise to around 20 degrees C within 48 h. When this exposure scenario was repeated four times, the impact of the temperature history on the different heat stability categories of vaccines varied between 2.4 and 36.0% shelf life loss. Oral polio vaccine was found to be the most affected vaccine. All other vaccines were affected with 2.4 to 10.4% life loss. Country assessments (real life situation with temperature variations between day and night) showed between 0.4% to 4.6% life loss when the boxes were exposed to ambient temperatures ranging from 11.7 to 39.8 degrees C over the 98 h 15 min test period.


CONCLUSIONS
The use of cool water packs is found to be a legitimate and safe practice for vaccines other than oral polio vaccine, so that cool water packs can safely replace frozen icepacks without any serious consequences on the ability of vaccines to confer protection against disease.
Kartoglu
Umit
U
Scientist, Family and Community Health/Department of Immunization, Vaccines and Biologicals, Performance, Quality and Safety L267, World Health Organization, 20 Avenue Appia, 27-Geneva 1211 Switzerland. kartogluu@who.int
Ganivet
Serge
S
Guichard
Stephane
S
Aiyer
Venkat
V
Bollen
Peter
P
Maire
Denis
D
Altay
Birhan
B
D002626:Chemistry, Pharmaceutical; D003080:Cold Temperature; D004349:Drug Packaging / Q000592:standards; D004355:Drug Stability; D004356:Drug Storage; D005615:Freezing; D017408:Guidelines as Topic; D006801:Humans; D002052:Myanmar; D009390:Nepal; D055550:Protein Stability; D012034:Refrigeration / Q000379:methods* / Q000592:standards; D013997:Time Factors; D014186:Transportation / Q000592:standards; D014421:Turkey; D014612:Vaccines / Q000737:chemistry*; D015030:Zimbabwe
D014612:Vaccines