WEDNESDAY, Jan. 18 (HealthDay News) -- A new vaccine to protect against meningococcus B, a common cause of bacterial meningitis, shows promise in clinical trials, researchers in Chile report.

Vaccines that protect from four other strains of Neisseria meningitides, a bacteria that causes meningococcal disease, are already in use or in the last stages of development, according to a news release from The Lancet. The other strains include A, C, W135 and Y.

The new research examined the effectiveness of the vaccine for strain B, which remains a significant source of meningococcal disease in North America, South America and Europe.

Researchers tested the vaccine called 4CMenB at 12 sites in Chile. More than 1,600 teens aged 11 to 17 were given either one, two or three doses of the vaccine at one-, two- and three-month intervals, or a placebo.

After two or three doses, nearly all of the teens had blood test results that indicated they were protected from meningococcus B, compared to 92 to 97 percent of teens who got one dose of the vaccine and 29 to 50 percent who received a placebo.

"This pivotal study shows that two doses of the novel 4CMenB vaccine separated by 1, 2, or 6 months provide a potentially protective immune response in almost 100 percent of adolescents irrespective of previous antibody status," the study authors wrote.

The study is published online Jan. 17 in The Lancet.

The study authors pointed out the vaccine had no harmful effects on the teens involved in the trial. They added the amount of protection the vaccine provides will depend on where people live since strains of the bacteria vary, and more research is needed to determine how this vaccine will affect other age groups.

"Further study is needed to provide information about the immunogenicity and tolerability of 4CMenB in various age groups, including infants, who bear the largest disease burden worldwide," they wrote.

Meningitis is an inflammation of the membranes covering the spinal cord and the brain. According to the U.S. Centers for Disease Control and Prevention, meningitis can be caused by a virus or a bacteria. The bacterial form is often more severe and can result in brain damage, hearing loss and death.

Before the 1990s, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis. Today, the Hib vaccine is part of routine pediatric immunizations.

More information

The U.S. Centers for Disease Control and Prevention provides more information on the prevention and control of meningococcal disease.