Scientists assess new vaccines to improve health of African children
21 October 2010
Respiratory infections and diarrhoeal diseases kill approximately 4 million children each year, with most deaths occurring in developing countries. New vaccines for Streptococcus pneumoniae, a bacterium that causes pneumonia, and rotavirus, the most common cause of severe diarrhoea, have proved successful in preventing the development of the diseases in clinical trials, but have yet to be used routinely in many parts of Africa.
As part of a £2.3 million project, scientists from Liverpool, London, Malawi, USA and Japan will monitor the impact of the vaccines as they are introduced in Malawi over the next five years.Focusing on three Wellcome Trust-funded research sites in Malawi, the team will investigate how effective the new vaccines are in areas where morbidity is high and strains of rotavirus and pneumococcus are diverse. Scientists will also assess whether conditions such as malnutrition and HIV, which are common in African children, could influence the success of the vaccination programme.
Rotavirus is the leading cause of severe, acute gastroenteritis among infants and young children throughout the world. Symptoms include severe diarrhoea and vomiting, leading to loss of fluid and dehydration. Streptococcus pneumoniae is a major cause of pneumonia, blood stream infection and meningitis.
Dr Nigel Cunliffe, from the University's Institute of Infection and Global Health, explains: "Early vaccination to prevent disease caused by rotavirus and Streptococcus pneumoniae is crucial in Africa, but we have limited evidence of how well these new vaccines will work in the world's most impoverished countries when delivered as part of the routine childhood immunisation schedule.
"Underlying medical conditions, the wide diversity of circulating strains in this region, and delayed immunisation may all adversely impact on vaccine performance.It is vital that the effectiveness of vaccination is carefully assessed in order to optimise the tremendous benefit these vaccines will bring to the health of children in Africa.Working in partnership with the Malawi Ministry of Health, this study will provide a framework for investigating other vaccine-preventable diseases across the country."
The research, funded by the Wellcome Trust, will be undertaken in collaboration with Professor Robert Heyderman, Director of the Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Dr Neil French from the London School of Hygiene and Tropical Medicine, as well as researchers at University College London, the US Centers for Disease Control and Prevention, Nagasaki University, and the Malawi Ministry of Health.
Image: Streptococcus pneumoniae, the species of bacterium that is the commonest cause of pneumonia. Courtesy of Debbie Marshall/ Wellcome Images