Routine Vaccinations and Child Survival

Routine vaccinations and child survival: follow up study in Guinea-Bissau, West Africa

Introduction
Measles vaccine is strongly associated with better childhood survival in developing countries. Since this
effect cannot be explained by the specific prevention of measles, standard measles vaccine may be associated with a non-specific beneficial activation of the immune system. This effect would be observed only in areas with high mortality. Similar studies of BCG, polio, and diphtheria, tetanus, and pertussis vaccines have not been carried out in countries with a high mortality.

Worldwide, BCG is the most widely used vaccine and has been recommended for tuberculosis control in developing countries for more than 40 years. The protection provided by BCG is controversial as it has variable efficacy in different settings. Routine vaccinations with diphtheria, tetanus, and pertussis vaccine and polio vaccine provide good protection against the specific diseases. The recommended schedule is based on studies of seroconversion and protection and on assumed feasibility of the schedule. The effect of these vaccines has been assumed to be proportionate to the impact of the specific infections.

Guinea-Bissau in West Africa is one of the world’s poorest countries. It has the sixth highest childhood mortality according to Unicef estimates. Since the early 1990s we have followed a representative cohort of 10 000 mothers and their children from the rural areas of Guinea-Bissau. Because the survival of recipients of routine vaccines has not been investigated in areas with high mortality, we examined the association between vaccination and survival in rural Guinea- Bissau.

Page updated 24 Aug 2007