January 31, 2011

By Oliver Yun, MSF USA Medical Editor

Niger 2009 © Guillaume Ratel

An MSF staff member in Niger readies a meningitis shot during a mass vaccination campaign in 2009.

In December, Doctors Without Borders/Médecins Sans Frontières (MSF) will support the national Ministries of Health of Niger and Mali to carry out meningitis vaccination campaigns using a new, low-cost, longer-lasting vaccine. This vaccine, which was recently endorsed by the World Health Organization (WHO), is a major improvement over older meningitis vaccines and has the potential to save thousands of lives each year.

Meningococcal meningitis is a serious, highly contagious bacterial infection of the brain and spinal cord. Around 10 percent of cases are fatal, and even with treatment up to 25 percent of patients suffer permanent damage, including hearing loss, mental retardation, and epilepsy. Epidemics of the disease routinely occur in the “meningitis belt” of sub-Saharan Africa—a massive expanse of more than 20 countries, from Senegal in the west to Ethiopia in the east—during the annual dry season between January and May. Each year, more than 400 million people are at risk of contracting the disease. During the 2009 epidemic season, more than 78,000 suspected cases were reported in Africa, and more than 4,000 people died from the disease, the largest number of fatalities in a single year since 1996.

In June, a new meningococcal conjugate A vaccine called MenAfriVac that had been developed by the Serum Institute of India was prequalified for use by the WHO. Developed specifically for Africa, the new vaccine protects against serogroup A meningitis. Meningitis is caused by different serogroups (A, C, Y, and W135), and the effectiveness of a given vaccine depends on which serogroups it targets and which serogroups are present in the affected region.

Compared with the existing meningitis A vaccine, the new vaccine provides four times greater protection, and this protection lasts for 10 years, compared with 3 years with the older vaccine. Another major benefit of the new vaccine is that it can help stop meningitis transmission by eliminating healthy carriers—people who are infected but do not manifest the disease, yet can still pass it on to others—thus conferring “herd immunity,” where immunization of part of the population provides protection for the whole.

MSF ordered 3 million doses of the new meningitis A vaccine as part of larger vaccination campaigns led by the Ministries of Health in Niger, Mali, and Burkina Faso, and the WHO. MSF will support the vaccination of 800,000 people in Mali and 600,000 people in Niger. These vaccination campaigns will target all those from 12 months to 29 years old. Future campaigns will target each year’s cohort of one-year-olds.

Previously, MSF teams carried out reactive vaccination campaigns against meningitis outbreaks, but because the existing vaccine is not highly effective, vaccination teams had to return every year in anticipation of new epidemics. Stocks of the older vaccine were also often limited. Now, with the advent and availability of the new vaccine, campaigns can be planned ahead of time in an attempt to prevent meningitis outbreaks before they occur.

With this more effective and longer-lasting vaccine, MSF and other health actors now have the opportunity to stop “chasing” meningitis A epidemics and can instead prevent them from occurring in the first place. However, the rollout of the new vaccine will take several years. In the meantime, existing vaccines will still need to be used.

Full coverage with the new vaccine in Niger, Mali, and Burkina Faso is expected by the end of 2011. For other countries in the meningitis belt, rollout of the new vaccine will depend on each country’s epidemiological situation in terms of meningitis infection, the readiness and willingness of national health authorities to conduct large-scale vaccination campaigns, and sufficient funding and support from the international health community