Immunization, Vaccines and Biologicals

Pneumococcal disease

Diseases caused by Streptococcus pneumoniae (pneumococcus) constitute a major global public health problem. Serious diseases that are often caused by pneumococci include pneumonia, meningitis and febrile bacteraemia; otitis media, sinusitis and bronchitis are more common but less serious manifestations of infection. Pneumococci are transmitted by direct contact with respiratory secretions from patients and healthy carriers.

It is estimated that in 2000, about 14.5 million episodes of serious pneumococcal disease occurred, resulting in about 826 000 deaths in children aged 1-59 months. In the developed world, serious disease occurs mainly in children under two years of age and in the elderly. In developing countries, the disease is common in children under two years, including newborn infants; rates of the disease in the elderly population are largely unknown. HIV infection and other conditions associated with immune deficiency greatly increase the likelihood of contracting pneumococcal disease. Growing resistance of pneumococcus to conventional antibiotics underlines the urgent need for vaccines to be used to control pneumococcal disease.

Pneumococcal vaccines are designed to cover the serotypes most frequently associated with severe pneumococcal disease. Currently, three pneumococcal conjugate vaccines covering 7, 10 and 13 serotypes (PCV7, 10 and 13) and an unconjugated polysaccharide vaccine covering 23 serotypes (PPV23) are marketed internationally. The 23-valent vaccine is primarily designed for use in older children and adults who are at high risk for pneumococcal disease. It is not licensed for use in children aged <2 years.

In 2007, WHO recommended the use of pneumococcal conjugate vaccines in all countries, urging that the highest priority for introduction be given to countries with high pneumonia and under-5 mortality rates.

WHO position papers

Related links

Last updated: 11 October 2011

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