CONTINUOUS RESEARCH RESULTS
Over the past 25 years, child mortality in Guinea-Bissau has fallen by more than 50%. Part of the reduction is ascribed to the vaccination programme. According to WHO, during the same years vaccination coverage in Africa has risen from around 50% to around 80%. WHO estimates that the vaccination programme averts 2-3 mio. deaths annually.
But if real-life effects of vaccines were measured, and taken into account in the way the vaccination programmes are designed and evaluated, vaccines could prevent many more deaths.
For example, the Bacillus Calmette-Guerin vaccine (BCG) which is recommended at birth to protect against tuberculosis is frequently given many weeks after birth. This presumably matters little to the risk of dying from tuberculosis which is not a common cause of death in very young children.
However, in clinical studies BCG vaccine prevents many early deaths which are unrelated to tuberculosis.
More information on clinical trials which have shown that early BCG vaccination prevents 38% of neonatal deaths
If BCG prevents deaths from other causes than tuberculosis early in life, all children should be vaccinated at birth. This does not happen. In Guinea-Bissau, only 38% of children in the rural areas are vaccinated in the first month of life. Since vaccination coverage is measured at 12 months of age there is no programme incentive to vaccinate early.
We have shown that an important reason for delayed vaccination is that the BCG vaccine is supplied in 20 dose vials and therefore a vaccine vial is not opened unless more than 10 children are due to be vaccinated on that day. Instead mothers are sent home and told to come back for vaccination on another day.
While this saves vaccine doses, it transfers costs to the families and may have serious impact on child mortality.
More information on cost of seeking BCG and projected impact on child mortality
Therefore we have suggested that vaccination coverage should not only be measured at 12 months but that BCG vaccination coverage should be measured at one month.
More information on BCG coverage indicators