A new superbug that causes meningitis and pneumonia in kids has public health officials worried: Serotype 19A of the Streptococcus pneumoniae bacterium eludes most antibiotics and a vaccine intended to prevent infection.

Rates of meningitis, pneumonia and bloodstream infections from the dangerous strain have increased from 2 in 100,000 children in 2001 to more than 10 per 100,000, the New York Times reports today. At the same time, life-threatening infections among the elderly have gone up fourfold, the newspaper notes.

The eight-year-old Prevnar vaccine inoculates infants and toddlers against seven strains of the bacteria that caused 70 percent to 80 percent of pneumococcus infections in the '90s, and within two years of its 2000 introduction, rates of those illnesses had fallen by 80 percent in some places. But the four-shot series never protected against serotype 19A, and now its manufacturer, Wyeth, is racing to develop a next-gen shot against that and five additional strains, the company's head of vaccine research and development, Emilio Emini, told the Times.

Health authorities said the vaccine isn't to blame for the rise in resistant strains of the bacteria. Still, the phenomenon suggests that Prevnar may have to be updated like the flu shot, the Pharmalot blog noted in a post last year about a surge in ear infections from serotype 19A. Scientists make new flu vaccine annually, based on the strains they guess will be most common in a given year.

(Image by iStockphoto/Carmen Martínez Banús)