Investigating cold-chain system and efficacy of vaccines reaching the end user in Turkey and related regulations

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 coldchain 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.