Dr Kirsty Le Doare’s group are working on solving the mystery of Group B Streptococcus, a bacteria with two faces, the same bug either potentially lethal or completely harmless and we do not yet understand why.
GBS disease is a major cause of infant mortality and morbidity globally. In Africa, the disease burden is thought to be particularly high. GBS normally colonises the gastrointestinal and vaginal tracts without harm. However, if a woman is colonised with the disease during pregnancy or upon delivery, GBS may be transmitted to the infant going on to cause infections such as GBS pneumonia, sepsis or meningitis soon after birth. There is a high mortality rate following infection and subsequent severe disability in up to 50% of GBS meningitis survivors.
The risk of GBS disease does not end at birth and babies are at risk for the first three months of life. Why GBS causes disease in infants and why there is such a defined period of risk is uncertain, but it is thought that antibodies transferred via the placenta are protective.
Vaccines against GBS are in development; however, phase III trials of GBS vaccines are hampered by large sample numbers required to prove efficacy. It is widely acknowledged that availability of a surrogate marker would have enormous impact as an alternative endpoint in clinical trials aimed at licensure. To facilitate global vaccines licensure requires epidemiological data, validated assays and prediction of a serocorrelate of protection.
Le Doare K, Faal A, Jaiteh M, Sarfo F, Taylor S, Warburton F, Humphries H, Birt J, Jarju S, Darboe S, Clarke E, Antonio M, Foster-Nyarko E, Heath PT, Gorringe A, Kampmann B et al., 2017, Association between functional antibody against Group B Streptococcus and maternal and infant colonization in a Gambian cohort, VACCINE, Vol: 35, Pages: 2970-2978
Le Doare K, Jarju S, Darboe S, Warburton F, Gorringe A, Heath PT, Kampmann B et al., 2016, Risk factors for Group B Streptococcus colonisation and disease in Gambian women and their infants, JOURNAL OF INFECTION, Vol: 72, Pages: 283-294,
Le Doare K, Taylor S, Allen L, Gorringe A, Heath PT, Kampmann B, Hesseling AC, Jones CE et al., 2016, Placental transfer of anti-group B Streptococcus immunoglobulin G antibody subclasses from HIV-infected and uninfected women to their uninfected infants, AIDS, Vol: 30, Pages: 471-475