A Chance for Every Child
Rey, Michel, UNESCO Courier
A chance for every child
THE goal of the Expanded Programme on Immunization (EPI), launched by the World Health Organization in 1974, is to ensure that by 1990 all the world's children are protected against six killer diseases: measles, poliomyelitis, diphtheria, pertussis (whooping cough), tetanus and tuberculosis.
These six target diseases have been given priority because each year they cause hundreds of thousands of deaths and tens of thousands of disabilities. Now they can be prevented by immunization. In theory measles and polio are eradicable, and diphtheria and whopping cough can be practically eliminated. For the other two diseases, the aims of EPI are rather different. The Programme gives priority to the prevention of neonatal tetanus; and confines itself to tuberculosis in children, of which the most serious manifestation is tuberculous meningitis. The BCG antituberculosis vaccine1 only protects children against contamination and cannot change the epidemiology of the disease, which is carried and transmitted mainly through adults.
1. BCG (bacillus Calmette-Guerin: named after the French scientists who produced the first attenuated tuberculosis vaccine in 1906.
EPI is implemented in two ways. The main trust is the immunization of children under a year old, who are given the six vaccines over at least three sessions. The second line of attack, against neonatal tetanus, is aimed at pregnant women and other women of childbearing age. Here, immunization before birth protects the child.
The aims of the Programme are ambitious. For the moment the chief objective is to give all the world's children access to immunization services. It is accepted that between now and 1990 it will be difficult to achieve the 90 per cent level of immunization coverage initially projected for the group of six vaccines. A 70 to 80 per cent coverage rate would be satisfactory. For neonatal tetanus, a more precise objective has been defined for 1990: reduction of its incidence to less than one case per thousand live births in countries which are still relatively widely affected and to eradicate the disease entirely in those countries where it has become a rarity.
EPI can be distinguished from other preventive medicine campaigns by the significant technological and operational constraints it faces, and by the fact that this form of prevention is basically managed by health services, the resources of which are mobilized at all levels.
The first constraint concerns the supply of vaccine. Vaccines are increasingly complex biological products, manufactured using advanced technology, and they are still largely made by industrialized countries. There are many obstacles to local production. Even India, a relatively well equipped country with a vast internal market, has not yet succeeding in producing all the vaccines it needs for domestic consumption. The use of low-quality, cheaply produced vaccines is unacceptable. Such vaccines are often less efficient, and are also less well tolerated. They will jeopardize the success of the Programme by discouraging people from taking part in it. Much of the vaccine used by EPI is supplied by international organizations or aid agencies and must conform with WHO standards.
The preservation of vaccines necessitates the maintenance of an uninterrupted "cold chain'. In many cases, the absence or breakdown of this chain has meant the failure of immunization, especially using heat-sensitive live vaccine such as the measles or the oral polio vaccines. A less temperature-sensitive measles vaccine has recently been developed, but the cold chain is still necessary.
Finally, most vaccines and administered by injection and syringes and needles have to be very carefully sterilized. It is possible for tetanus to be transmitted by the injection, and today the risks of transmitting hepatitis B and AIDS by syringes must be stressed. …