The U.S. Food and Drug Administration (FDA) has approved the use of Sanofi Pasteur's bacterial meningitis vaccine Menactra in children as young as 9 months.

Menactra already is approved for use in people ages 2 through 55 years.

Meningococcal disease is a life-threatening illness caused by bacteria that infect the bloodstream (sepsis) and the lining that surrounds the brain and spinal cord (meningitis). Neisseria meningitidis is a leading cause of meningitis in young children.

Even with appropriate antibiotics and intensive care, between 10 percent and 15 percent of people who develop meningococcal disease die from the infection, the FDA said. Another 10 percent to 20 percent suffer complications such as brain damage or loss of limb or hearing.

The highest rate of meningococcal disease occurs in children under one year of age. With today’s approval, Menactra can now be used in children as young as 9 months of age to help prevent this potentially life-threatening disease, said Karen Midthun, director of FDA's Center for Biologics Evaluation and Research.

The safety of Menactra in children as young as 9 months was evaluated in four clinical studies in which over 3,700 participants received the vaccine. The most common adverse events reported in children who received Menactra at 9 months and 12 months of age were injection-site tenderness and irritability, the FDA said. Occurrence of fever was comparable to other vaccines routinely recommended for young children.

Menactra is given as a two-dose series beginning at 9-months, three months apart; and the study results showed the vaccine produces antibodies in the blood that are protective against the disease.

Menactra was originally approved on Jan. 14, 2005, for use in individuals ages 11 years through 55 years and was approved in October 2007 for children as young as 2 years.

Sanofi Pasteur is the vaccines division of Sanofi-Aventis.