Meningitis cases fall 94% following vaccine introduction

The introduction of MenAfriVac in 2010 was viewed as a big event at the time. Its story of a nonprofit stepping into the domain of Big Pharma and developing a meningitis vaccine gained international news coverage. Until this week though, nobody knew the full significance of that 2010 launch.

Last year, vaccinated areas of Chad reported 94% fewer cases of meningitis than regions that are yet to be immunized. The dramatic fall follows a December 2011 immunization campaign, in which 1.8 million people in three regions of Chad received MenAfriVac. In 2012 these regions experienced 2.5 cases of meningitis of any kind per 100,000 people, and none of the A strain targeted by the vaccine. Unvaccinated regions reported more than 43 cases per 100,000, researchers write in the Lancet.

"This is one of the most dramatic outcomes from a public health intervention that I have seen during a long career of research in Africa. There are now real prospects that the devastating effects of this infection in Africa can be prevented," study author professor Sir Brian Greenwood said. Greenwood has studied meningococcal meningitis in Africa since the early 1970s and has seen the impact it has on the region. In bad years, the bacteria has infected 250,000 people across central Africa's 'meningitis belt,' killing up to 10%. A 2009 outbreak is suspected to have killed at least 5,000 people in 14 countries, the AFP reports.

A vaccine could have prevented many of these deaths. Since 2010, 100 million people in the region have received MenAfriVac, a vaccine nonprofit PATH developed with the World Health Organization. The Bill & Melinda Gates Foundation funded development of the vaccine, and contributed to the Chad study. The goal now is to continue the rollout of the vaccine to protect more of the 450 million people at risk of contracting meningitis A in central Africa.

Evaluations of the effectiveness of MenAfriVac are continuing too. While the Chad data is encouraging, the duration of protection is still unclear, and a shift in the prevalence of meningitis strains could cut the effectiveness of the vaccine.

- here's the AFP article
- check out the Lancet paper
- read the FT's take
- view the Wellcome Trust release