It offers no protection in up to 4 per cent of children whose genetic profile nullifies the vaccine's effectiveness.
Researchers from the Mayo Clinic have identified 27 genes that will determine whether the vaccine will be effective. Children with the genetic differences respond poorly to the vaccine, interfering with antigen interactions, inflammation and genetic pathways.
Although it's not known just how many children may not be protected by the vaccine, the Mayo researchers identified 25 children from a group of 738 vaccinated individuals who had a 'low vaccine response'. If this is a typical sub-set, around 4 per cent of children may not be protected by the vaccine.
The researchers say their findings underline the importance of profiling and the creation of more individualised vaccines.
(Source: PLoS One, 2013; 8: e62149).