Investigating Cold-Chain System and Efficacy of Vaccines Reaching the End User in Turkey and Related Regulations
Hamza ÖZDEMİR*, A. Yekta ÖZER*°
* Hacettepe University, Faculty of Pharmacy, Department of Radiopharmacy, Ankara, Turkey

° Corresponding Author E-mail: ayozer@hacettepe.edu.tr

Summary

Immunization programs are implemented according to the Expended Program of Immunization (EPI) in the WHO member countries. The cold-chain component of the program is just as important as the immunization coverage. Vaccines are produced and released as safe and efficient. But, how safe and efficient are they by the time they’re administered in situ?
The aim of our study is to monitor and to evaluate the cold-chain for vaccines used in Turkey between the Primary Vaccine Store and the health service on the field. Furthermore, we collected batches designated vaccines used in this study to Primary Vaccine Store in cold chain conditions and retested tested them for their potency and virus content. The Hepatitis B Vaccine and Oral Polio Vaccine (OPV) were monitored due to their high sensitivities against freezing and high temperatures,, respectively.
We sent the products to 7 geographical regions in Turkey using small continuous temperature recorders that record temperature data for long periods of time. The health workers were not informed that they would receive vaccines with these spying thermometers. A small note was put in the small boxes of vaccines informing health workers what they had to do after receiving them.
Evaluating the thermometers collected from the field, we found that the cold chains in warehousing and transportation were reliable. And the potency tests performed by the National Control Authority were found to be satisfactory according to the references.
The results obtained showed that the vaccines designated the 7 geographical regions were transported to the targets (health services) safely and efficiently, by maintaining the cold chain conditions.
 
Key Words : Vaccines, Freezing effect to vaccines, cold-chain, public health strategy, storage and transportation of vaccines.