Scientists boost newborn immunity to help reduce infection in African children

2 August 2011
Sarah BurlScientists have found a new approach to overcome a major barrier to immunising newborn African children. This discovery, carried out by a multinational team including researchers at Medical Research Council (MRC) The Gambia, could help refine vaccines so that they are specifically designed to work with a newborn’s immune system and go some way to helping the millions of children under five who die each year from infections such as pneumonia and diarrhea.

Infant mortality from infectious diseases is a huge cause of death globally, in part because newborns do not yet have a sophisticated enough immune system to respond to most vaccines. The study showed that by incorporating a group of proteins called ‘Toll Like Receptors (TLR)’ into the vaccination process, they could help stimulate aspects of the newborns’ immune systems so that vaccines are more likely to offer protection against infection.

The ability to immunise newborns would not only close a baby’s window of vulnerability to serious infections during the first months of life, such as pneumococcus which causes pneumonia and rotaviruses which cause severe diarrhea but it would also provide a way to offer vaccinations to infants at birth rather than waiting until they are a few months old. This is critical in developing countries with fewer resources, where it’s harder to track how many children have been vaccinated and at what age.

In the current study published today in PLoS ONE, the team treated blood samples from 120 Gambian infants with a panel of different TLR stimulators, and measured how they each affected the infants’ production of cytokines, a key part of the immune system which is typically absent in newborn children. The infants ranged from newborn to 12 months of age, allowing the researchers to examine how the effects of this treatment were affected by age and to see if immunity could be sustained over time. The team found that one stimulator in particular, known as TLR8, helped boost the newborn’s immune system throughout the infant’s first year of life.

The research was funded by the Medical Research Council (MRC (UK), the Bill & Melinda Gates Foundation and the NIH, and led by Dr Sarah Burl of MRC The Gambia and Imperial College London and Dr Katie Flanagan of MRC The Gambia in collaboration with Dr Ofer Levy of Children’s Hospital Boston, Harvard Medical School.

Dr Sarah Burl from Imperial College London who carried out the work at MRC The Gambia says “Our international collaboration with Children’s Hospital Boston at Harvard Medical School in the US highlights the importance of such infant studies at the Medical Research Council in The Gambia. These results suggest use of TLR8 could help improve vaccine responses, reduce the number of immunisations given to each child and hopefully go some way to tackling of the number of young children dying from infections especially in vulnerable areas of the world,”

Dr Ofer Levy at the Children’s Hospital Boston, part of the Harvard Medical School adds “The adjuvant could be combined with any vaccine, and if things work well, it could provide single-shot protection at birth”

Results will appear in the open-access journal Public Library of Science (PLoS) ONE on April 13.

For further information contact communications [at] mrc [dot] gm