From Boston, at a meeting of the Infectious Diseases Society of America
Following the national introduction in 2000 of a vaccine for children against seven common strains of pneumococcus, serious infections caused by the bacteria decreased in children. The resulting dip in the microbe's overall prevalence in kids led to fewer infections in adults. A concern, however, is that rare strains of pneumococcus may arise to replace those cut down by the vaccine.
Infection with HIV, the AIDS virus, puts people at particular risk from pneumococcus, so researchers in several states collected 6 years' worth of data on severe pneumococcal infections among adults with HIV. The researchers also analyzed bacteria taken from those people to determine which pneumococcus strain was responsible.