London, Aug 19 (IANS): British investigators have discovered two new vaccines that can prevent the transmission of meningitis bacteria from person to person.

The vaccines do this by reducing "carriage" of the responsible bacteria in the nose and throats of the population.

The standard practice is to vaccinate with the aim of inducing high levels of antibodies in the blood to protect against the disease, but we know that these antibodies can disappear over the course of a few months.

"The new findings tell us that the vaccines also have an effect on carriage in the throat and explains why they can be so effective across the population," said Robert Read, a professor of infectious diseases at University of Southampton.

The study took place over 10 centres across Britain and tested the effectiveness of two meningitis vaccines - MenACWY-CRM and 4CMenB - on participants aged 18 to 24.

Participants were either given two doses of a control vaccine, two doses of the 4CMenB vaccine or one dose of MenACWY-CRM and then a placebo.

MenACWY-CRM was shown to reduce carriage rates by 39 percent while the 4CMenB vaccine reduced carriage rates by between 20 and 30 percent.

Meningitis is an infection of the meninges - the membrane that surrounds the brain and spinal cord.

"We have shown that vaccines modify the way the bacteria are carried, so even when the antibodies are no longer present in the blood, the carriage in the throat is still prevented, and so is onward transmission of the infection to others," Read concluded in a Lancet paper.