December 8, 2008

One-fifth of meningitis vaccine effective

One-fifth of the standard dose of a commonly used meningitis vaccine may be as effective as using the full dose, researchers in Norway said.

Researchers at the Norwegian Institute of Public Health and colleagues at Epicentre -- the research arm of Doctors Without Borders/Medecins Sans Frontieres -- and Mbarara University of Science and Technology in Uganda said the finding should allow scarce vaccine resources to be stretched further, especially during epidemics in Africa.

In 2004, a randomized clinical trial of 750 healthy volunteers ages 2-19 took place in Uganda. Their immune response, assessed by serum bactericidal activity, was measured for one-fifth and one-10th doses compared to a full dose.

Serum bactericidal activity response and safety/tolerability using one-fifth dose were comparable to a full dose for three serogroups -- A, Y, W135, but not a fourth -- C.

The study, published in the journal PLoS Neglected Tropical Diseases, said that in view of the current shortage of meningococcal vaccines for Africa, the use of one-fifth fractional doses should be considered as an alternative in mass vaccination campaigns.