The vaccine given to children to immunise against serious pneumococcal disease does not offer full protection, reveals research from the Sahlgrenska Academy at the University of Gothenburg, Sweden, finding that the number of cases diagnosed has tripled over the past 50 years.
Each year an estimated 1 million children worldwide die as a result of pneumococcal disease. Worst affected are those in poor countries, but pneumococcal bacteria cause disease and suffering in all age groups and in all countries, including Sweden.
There are currently two types of active vaccine: polysaccharide vaccines, which protect against more types of pneumococcal bacteria but cannot be given to children under the age of two, and conjugated vaccines, which can be given to infants but protect against fewer types.
In his thesis, Erik Backhaus, infection specialist at Sk-vde Hospital and doctoral student at the University of Gothenburg's Sahlgrenska Academy, looks at all cases of serious pneumococcal disease in children and adults in the V-stra G-taland region of Sweden between 1998 and 2001. His studies show that the latest conjugated vaccines theoretically offer protection against around 70% of infections. "But around 95% of infections are caused by serotypes covered by the polysaccharide vaccine," says Backhaus. "This vaccine cannot be administered to children under two years of age, which means that it cannot be used in those who need it most."
Risk of death is age-related