Mobile vaccine carrier with a passive cooling system comprising: a housing having a lid notably hinged to a base member , so that the lid can be moved between a closed position and an open position; a vaccine storage member disposed within the housing and defining a storage space for a plurality of vaccine containers (V); and at least one cooling element disposed within the housing ; the vaccine storage member further comprising: an inner container defining the storage space and having an inlet opening for placing and removing vaccine containers (V); a removable vaccine container holder for temporarily storing vaccine containers (V); and a cover member disposed on the lid , wherein the vaccine container holder comprises an abutment portion abutting against an outer portion of the inner container so that the inlet opening is covered by the vaccine container holder ; and wherein at least a part of the cover member protrudes into the storage space when the lid is in the closed position; wherein the vaccine carrier further comprises a measuring device for monitoring the temperature within the storage space; wherein the measuring device has a sensor arrangement comprising a temperature sensor for monitoring the temperature in the storage space; wherein the sensor arrangement is supported on the cover member and wherein the temperature sensor is disposed within the vaccine storage member when the lid is in the closed position; and wherein the cover member comprises an elongated member with the temperature sensor being supported on an end portion of the elongated member , characterized in that the elongated member is integrally formed with the cover member . a housing having a lid notably hinged to a base member , so that the lid can be moved between a closed position and an open position; a vaccine storage member disposed within the housing and defining a storage space for a plurality of vaccine containers (V); and at least one cooling element disposed within the housing ; the vaccine storage member further comprising: an inner container defining the storage space and having an inlet opening for placing and removing vaccine containers (V); a removable vaccine container holder for temporarily storing vaccine containers (V); and a cover member disposed on the lid , an inner container defining the storage space and having an inlet opening for placing and removing vaccine containers (V); a removable vaccine container holder for temporarily storing vaccine containers (V); and a cover member disposed on the lid , wherein the vaccine container holder comprises an abutment portion abutting against an outer portion of the inner container so that the inlet opening is covered by the vaccine container holder ; and wherein at least a part of the cover member protrudes into the storage space when the lid is in the closed position; wherein the vaccine carrier further comprises a measuring device for monitoring the temperature within the storage space; wherein the measuring device has a sensor arrangement comprising a temperature sensor for monitoring the temperature in the storage space; wherein the sensor arrangement is supported on the cover member and wherein the temperature sensor is disposed within the vaccine storage member when the lid is in the closed position; and wherein the cover member comprises an elongated member with the temperature sensor being supported on an end portion of the elongated member , characterized in that the elongated member is integrally formed with the cover member . <EOS>