Drugmaker Wyeth is seeking U.S. approval to sell a new version of its blockbuster infant vaccine Prevnar, which protects against more strains of a germ that causes pneumonia.

Prevnar currently protects against seven of the most common strains of a strep bacteria. The germ can cause ear infections and pneumonia and life-threatening conditions including bloodstream infections and meningitis.

The new version, called Prevnar 13, protects against those seven strains of bacteria, plus six others that cause the same diseases. The six new strains include one that is becoming more prevalent around the world and often is antibiotic-resistant.

Wyeth, which has U.S. headquarters in Collegeville, applied for Food and Drug Administration approval today and is hoping for an expedited decision.

Peter Paradiso, vice president for scientific affairs at Wyeth Vaccines, said the company still plans to apply for approval for Prevnar 13 for adults next year.    - Miriam Hill