((MH:"Refrigeration" OR TI:("Refrigeration" OR "Refrigeración" OR "Refrigeração" OR "refrigeración" OR "Cold Chain" OR "Cadena Fría" OR "Corrente Fria" OR "Cadeia Frigorífica" OR "Rede de Frio" OR "Rede Frigorífica" OR "Chaine du Froid" OR "Chaîne du Froid" )) AND (MH:Vaccines OR ti:vaccine$ or ti:vacuna$ or ti:vacina$ or ti:immunization or ti:inmunizacion or ti:imunizacao))
Databases
MEDLINE, LILACS, CDSR - Cochrane Systematic Reviews Database, CENTRAL Controlled Clinical Trials : CENTRAL Controlled Clinical Trials, DARE - Database of Abstracts of Review of Effects, NHS Economic Evaluations Database, HTA - Health Technology Assessment Database, WHOLIS (WHO Library Database), PAHO (PAHO Library Database), All VHL data bases.
