Meningitis mass vaccination sees cases drop 94%

A mass vaccination campaign in Chad in 2011 reduced all cases of meningitis by 94% and saw no cases of serogroup A meningococcal meningitis detected in 2012. The finding comes from an evaluation by an international team including Oxford University scientists and led by the London School of Hygiene & Tropical Medicine and Centre de Support en Santé Internationale (CSSI) in Chad. Several groups of bacteria can cause meningitis, the most important being meningococcus , which can trigger inflammation around the brain and spinal cord leading to disabilities such as deafness, paralysis, or death. The team looked at how a vaccine targeting serogroup A, the most common meningococci group in sub-Saharan Africa, affected both cases of infection and the number of people carrying the disease - carriers, who can transmit the infection through coughing and sneezing, can be detected by analysing throat swabs. Approximately 1.8 million people aged 1-29 years received a single dose of PsA-TT (also known as MenAfriVac ) in three regions of Chad in December 2011. The incidence of meningitis of any kind in these regions during the 2012 meningitis season was 2.5 per 100,000 people, compared to an incidence of 43.6 per 100,000 in regions where mass vaccination had not been undertaken - a 94% drop in the incidence of meningitis. No cases of serogroup A meningococcal meningitis were detected in the three vaccinated regions.