Background: Vaccines are heat-labile medications, and to guarantee their immunogenicity and safeguarding effectiveness as part of immunization programs, it is absolutely essential that the "Cold Chain" go unbroken. Fundamental thereto is the personnel responsible for the vaccines, who must know the stability-related characteristics of each preparation so as to prevent handling errors. The purpose of this study was that of ascertaining how the cold chain is kept intact in primary care systems in one healthcare area of the Autonomous Community of Madrid, as well as determining the degree of information possessed by those responsible for vaccines as far as their heat-stability is concerned.
Methods: A cross-sectional study has been made at 46 primary care vaccination points. The data was gathered by means of a personal interview by one single researcher.
Results: The participation rate was 93.5% (43/46). In all cases, there was a maximum and minimum thermometer and monthly temperature record. An unsuitable temperature was found in three cases (6.97%). The percentage of professionals who were aware of the effect freezing has on vaccines varied greatly: 53.5%, 51.2%, 44.2% and 53.5% for diphtheria-tetanus-pertussis (DTP), hepatitis B (HBV), oral polio (OPV) and measles-mumps-rubella (MMR) respectively. And only 32% were familiar with the shake test.
Conclusion: The professionals were found to be properly trained regarding the effect which high temperatures have on vaccines, but it is necessary for their training with regard to the instability of adsorbed preparations when frozen must be further strengthened.