One-fifth dose of scarce meningitis vaccine as effective as full dose

Washington, Dec 7 (ANI): Just one-fifth of the standard dose of a commonly used meningitis vaccine can turn out to be as effective as using the full dose, according to a new study.

Scientists hope that the new finding may allow scarce vaccine resources to be stretched further, especially during epidemics in Africa.

In a study initiated by the Norwegian Institute of Public Health, together with Epicentre (the research arm of Doctors Without Borders/Médecins Sans Frontières), and Mbarara University of Science and Technology in Uganda, immune responses in patients receiving smaller doses of a meningitis vaccine were found to be comparable to a full dose.

Scientists conducted a randomized clinical trial of 750 healthy volunteers (2-19 years old) in Uganda in 2004.

Their immune response, assessed by serum bactericidal activity (SBA), was measured for 1/5 and 1/10 doses compared to a full dose. SBA response and safety/tolerability using 1/5 dose were comparable to a full dose for three serogroups (A, Y, W135), but not a fourth (C).

Keeping in mind the current shortage of meningococcal vaccines for Africa, the use of 1/5 fractional doses should be considered as an alternative in mass vaccination campaigns.

The study's findings were used for a 2007 WHO recommendation that a fractional dosing strategy be utilized in the event of severe vaccine shortages during a meningitis epidemic.

The results have now been published in PLoS Neglected Tropical Diseases. (ANI)