Vaccines in the national immunization programme
Bass, A.G.
Papua and new Guinea Medical Journal 36(2): 141-157
1993
ISSN/ISBN: 0031-1480 PMID: 8154196 Document Number: 332030
Although Papua New Guinea agreed to reach 90% immunization of children under one year of age, this country and 5 others were unable to reach the coverage target. A survey of facilities was conducted, and analysis revealed serious systems failures and operational problems. Consequently, large numbers of children were receiving ineffective vaccines. When immunization coverage is low, disease is transmitted to those without coverage. For example, a failure of a single dose of the diphtheria-pertussis-tetanus (DPT) or oral polio vaccine results in only partial protection and the ability to transmit the diseases purportedly covered. There is great waste of effort and work, money, health worker time, facilities use, and equipment and vaccines, when inadequate coverage is achieved. Improvements are needed in assuring vaccine potency, adequate distribution, maintenance of the cold chain, and transportation of vaccine supplies. The causes of vaccine damage include the distribution chain of international supplies, vaccine temperatures by type of vaccine, vaccine conditions, vaccine storage conditions, storage risk factors, kerosene refrigerator conditions, sanitary immunization practices, and quality assurance points in the distribution chain. There were situations where boxes were supposed to be lined with frozen ice packs, but there were inadequate numbers of ice packs; road transport time with packs should be 1 day or less, when in fact it took 1-2 days, and air shipments could take a week. Placement in refrigerators may mean warming on one shelf and freezing on another shelf. When mobile teams transported vaccines to rural areas, the carrying boxes were insufficiently packed for transport longer than 1 day. Recommended measures were procurement of appropriate vaccines and equipment, development of guidelines, instructions and supervision, and provision of training. Area medical stores need to perform quality assurance when vaccines arrive, are being unpacked, or are in storage before shipment to another location.