title: Hepatitis B vaccine freezing in the Indonesian cold chain: evidence and solutions.
abstract: OBJECTIVE
  To document and characterize freezing temperatures in the Indonesian vaccine cold chain and to evaluate the feasibility of changes designed to reduce the occurrence of freezing.
  
  
  METHODS
  Data loggers were used to measure temperatures of shipments of hepatitis B vaccine from manufacturer to point of use. Baseline conditions and three intervention phases were monitored. During each of the intervention phases, vaccines were removed progressively from the standard 2-8 degrees C cold chain.
  
  
  RESULTS
  Freezing temperatures were recorded in 75% of baseline shipments. The highest rates of freezing occurred during transport from province to district, storage in district-level ice-lined refrigerators, and storage in refrigerators in health centres. Interventions reduced freezing, without excessive heat exposure.
  
  
  CONCLUSIONS
  Inadvertent freezing of freeze-sensitive vaccines is widespread in Indonesia. Simple strategies exist to reduce freezing - for example, selective transport and storage of vaccines at ambient temperatures. The use of vaccine vial monitors reduces the risk associated with heat-damaged vaccines in these scenarios. Policy changes that allow limited storage of freeze-sensitive vaccines at temperatures >2-8 degrees C would enable flexible vaccine distribution strategies that could reduce vaccine freezing, reduce costs, and increase capacity.
authors.affiliation: Program for Appropriate Technology in Health, Seattle, WA 98107, USA. cnelson@path.org
authors.forename: Carib M
authors.initials: CM
authors.lastname: Nelson
authors.forename: Hariadi
authors.initials: H
authors.lastname: Wibisono
authors.forename: Hary
authors.initials: H
authors.lastname: Purwanto
authors.forename: Isa
authors.initials: I
authors.lastname: Mansyur
authors.forename: Vanda
authors.initials: V
authors.lastname: Moniaga
authors.forename: Anton
authors.initials: A
authors.lastname: Widjaya
mesh_terms: D003080:Cold Temperature; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods*; D005240:Feasibility Studies; D017325:Hepatitis B Vaccines / Q000592:standards* / Q000600:supply & distribution*; D006801:Humans; D007214:Indonesia; D009936:Organizational Innovation; D014186:Transportation / Q000379:methods*; D014612:Vaccines / Q000592:standards / Q000600:supply & distribution
chemical_list: D017325:Hepatitis B Vaccines; D014612:Vaccines