Immunization--dramatic new evidence.

The current EPI (Expanded Programme on Immunization) vaccines do not specifically target the organisms that lead to the two main causes of death in children - pneumonia and diarrhoea. This implies that the EPI vaccines will have only a modest effect on total child mortality. However, recent evidence suggests that measles and BCG vaccines dramatically reduce child mortality through nonspecific effects - that is, they reduce mortality from many causes, not just measles and tuberculosis. The combination of BCG at birth and measles vaccine at 6 months probably reduces total mortality to about one-third of its previous level. This means that immunization must now have the very highest priority. If we could improve immunization in Papua New Guinea so that all children received BCG, measles, diphtheria-pertussis-tetanus and polio vaccines, we would reduce child mortality from 120 to approximately 52 per 1000 livebirths - a truly spectacular reduction. The old polysaccharide pneumococcal vaccine is safe and effective and bulk purchases are likely to cost US$1 a dose or less. Further studies are needed of the effects of pneumococcal vaccine. Immunization of mothers and babies might reduce child mortality by 20%, at a cost of only US$83 per life saved. The available evidence suggests that one dose of pneumococcal vaccine given to every Papua New Guinean over 5 years of age every 5 years would save approximately 6600 lives a year and the vaccine would cost only US$121 per life saved. It will not be easy to achieve high immunization rates throughout Papua New Guinea. Vaccines will have to be given the highest possible priority, with curative medical services secondary to immunization. Health workers, government, the general population and overseas donors will have to be convinced of the very great benefits that will come from effective immunization. A sustained education campaign will be needed in addition to the establishment of an effective delivery system. The time has come for a radical shift in emphasis in Papua New Guinea: from hospitalization to immunization.