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Indian Journal of Medical Microbiology, Vol. 28, No. 2, April-June, 2010, pp. 184-185 Correspondence Status of vaccine cold chain maintenance in Delhi, India *S Sachdeva, U Datta Directorate General of Health Services (SS), Ministry of Health and Family Welfare, Nirman Bhawan, New Delhi-110 108, Department of Education and Training (UD), National Institute of Health and Family Welfare, Munirka, New Delhi - 110 067, India Correspondence Address: *Directorate General of Health Services, Ministry of Health and Family Welfare, Nirman Bhawan, New Delhi-110 108, India, drsandeepsachdeva@gmail.com Date of Submission: 29-Sep-2009 Code Number: mb10057 PMID: 20404476 DOI: 10.4103/0255-0857.62507 Dear Editor Immunisation is a critical component of childhood survival strategy throughout the globe. It is recommended that vaccine should be strictly preserved in the temperature range of 2°-8°C. Studies in Australia, Great Britain, United States, Canada, Pakistan, Malaysia, Hungary, Mongolia, Indonesia and other countries have found widespread freezing at many levels of vaccine distribution system leading to questionable potency especially of Hepatitis B. [1] With this background, we undertook a study in a randomly selected municipal zone of Delhi, India, covering 32 government urban dispensaries and five medical store depots (MSD) after taking permission from competent authorities. Data was collected by a single investigator using observation checklist to ascertain cold chain maintenance of vaccines with the view to assess possible freezing. The type of cold chain equipment (CCE) used for storing vaccines was domestic type refrigerator, mini refrigerator and ice-lined refrigerator (ILR) in 21 (65.62%), 9 (28.12%), and two (6.25%) dispensaries respectively. In eight [25.0%], CCE was found attached to electric output through voltage stabilizer and for efficient cooling was present at least 10 cm away from the wall/adjoining structures in 21 (65.62%) dispensaries. The CCE were kept away from direct sunlight in all however ventilation was non-existent in 3 [9.3%] health facilities. Temperature chart with two-entries per day was maintained in 23 (71.87%) and was found pasted on CCE in 10 [43.42%] and placed on adjoining table in 13 [56.52%] health facilities respectively. However, discrepancy was noted among 14 [43.75%] especially for the entries made on the day of visit and more so when chart was placed away from CCE. Food articles including milk containers were present in CCE in 17 (53.12%) dispensaries. Ice-formation [more than 6mm] in the freezer section of CCE was found in 12 [37.5%] dispensaries suggestive of lack of regular defrosting. In 18 (56.25%) health facilities, the temperature was within normal range [2°-8°C] whereas in 14 (43.75%) it was below 2°C Celsius. Heat-sensitive vaccines [polio/measles/BCG] was stored correctly in all, on the contrary, freeze-sensitive vaccines [Hepatitis B/DPT/DT] were stored correctly in 20 (62.5%) health facilities only. In the rest 12 (37.5%), these were stored incorrectly in first shelf/chiller trays of refrigerator along with other heat-sensitive vaccines and/or floor of ILR. It was encouraging to note that vaccines were not placed in the door section of CCE in any of the dispensaries. At Medical Store Depot [MSD], temperature in CCE was found to be within normal-range [2°-8°C] at 3 [60.0%] and below 2°C in another 2 [40.0%] and freeze sensitive vaccine [Hepatitis B/DPT] was stored incorrectly on the floor of ILR in 1 [20.0%] MSD. Freeze-sensitive vaccines like Hepatitis B/DPT/DT/TT ideally should be preserved in middle shelf of refrigerator or top section/basket in ILR. The freezing point e.g. for Hepatitis B vaccine is -0.5° Celsius and once frozen, loses potency with compromised capacity to produce protective immunogenicity. In 14 (43.75%) dispensaries and 2 [40.0%] MSDs temperature was found to below 2° C& there was all probable reasons that Hepatitis B vaccine was exposed to freezing temperature (especially overnight exposure) resulting in questionable potency. Such events of administration of vaccines become mere 'statistics' in the monthly performance reports of health facility with no outcome in the form of production of protective antibodies in the recipients. The study has a wider ramification since Government of India and some of the States have included Hepatitis B vaccine in Childhood Universal Immunisation Programme. Lot of emphasis is being given currently for protection of vaccine from exposure to higher emperature. However, facts need to be reiterated & reminded that temperature is double-edged sword for vaccines. Heat-sensitive (like OPV/BCG/Measles) and freeze-sensitive (like Hepatitis B/DPT/DT) vaccines needs to be strictly preserved with in the recommended temperature range of 2°-8°C. References
Copyright 2010 - Indian Journal of Medical Microbiology |
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