Pneumonia Genome Yields Vaccine Targets Vaccines inspired by a search of a germ's genome protect mice against some pathogenic strains of Streptococcus pneumoniae. The bug commonly causes pneumonia, meningitis, and middle ear infections in children. If this type of vaccine works in humans, it might also provide wide protection for the elderly and people with weakened immune systems.
Experts hail the finding as one of the few reports of vaccines gleaned from a bacterial genome.
Several vaccines against Streptococcus pneumoniae are already available, but they have limitations. One vaccine directs the immune system to attack carbohydrates found in 23 of the most pathogenic strains. Unfortunately, carbohydrate-based vaccines don't elicit much of an immune response in children, the elderly, or immunocompromised people. A newer vaccine incorporates proteins as well as carbohydrates, Because it only fights seven strains, however, some dangerous ones may slip through the cracks. When a rough draft of the S. pneumoniae genome sequence became available a few years ago, Scott Koenig at MedImmune Inc. in Gaithersburg, Maryland, and colleagues thought they might be able to come up with a protein-based vaccine that would protect against many strains.