Estimated costs attributable to events of "out-of-temperature" in the stockpiling of hexavalent vaccines occurring in Italy.

BACKGROUND: Antigens contained in vaccines are inherently unstable biologically; such a characteristic is conferred by their three-dimensional structure. Preserving the ability of the vaccines to protect against disease is necessary to ensure the supervision and monitoring of all steps of the cold chain. DTPa-HBV-IPV/Hib vaccine (Infanrix hexaTM, GSK Vaccines, Belgium) is designed to prevent disease due to diphtheria, tetanus, pertussis (DTP), hepatitis B virus (HBV), poliomyelitis and Haemophilus influenzae type b (Hib); it was first licensed for use in Europe in 2000 and is currently licensed in at least 95 countries. Since October 2013, more than 102 million doses of GSK's DTPa-HBV-IPV/Hib vaccine have been distributed globally, with nearly 15 million doses distributed in Italy. DTPa-HBV-IPV/Hib components are stable up to a temperature of 25°C for 72 hours. Lacking of officially approved stability data may generate some concern in case of cold chain accidents.

METHODS: An analysis based on collected data was carried out to estimate potential costs attributable to events of "out-of-temperature" in the stockpiling of hexavalent vaccines occurring in Italy in 2014.

RESULTS: The analysis, based on real data, documented that the loss for the National Health Service (NHS) was in the range of 100,000 - 400,000 euros in one year. However, the amount of money that in principle could have been lost would have ranged between nearly half and one million euros/year.

CONCLUSIONS: A substantial loss of money was avoided thanks to the availability of officially approved stability data for GSK's DTPa-HBV-IPV/Hib vaccine.