Published on September 13, 2013 at 8:29 AM
A further study of meningococcal carriage—in an age-stratified sample of residents from the rural area of Mandelia—identified 32 serogroup A carriers in 4278 residents 4 months before immunisation, and just one serogroup A case in 5001 people tested 4–6 months after the vaccine was introduced.
The authors point out that the absence of meningitis cases in residents of the vaccinated areas either too old (30+ years) or too young (<1 year) to be immunised was likely to be the result of the vaccine substantially reducing carriage and transmission of the bacterium.
According to Greenwood, “While our findings support the continuing roll-out of this vaccine across the African meningitis belt, continuing surveillance and further carriage studies in countries of the African meningitis belt will be needed to confirm the duration of protection provided by this vaccine, and whether elimination of the serogroup A meningococcus will be followed by an upsurge in cases caused by meningococci belonging to other serogroups.”
Commenting on the study, Johannes Elias from the University of Wuerzburg in Germany says, “These findings might finally usher in the beginning of elimination of serogroup A meningococci in the meningitis belt…Further research should focus on the development and validation of serological correlates of protection and on the establishment of improved methods for detection of carriage, because exact duration of protection and age-stratified carriage prevalences are needed for the identification of optimum vaccination strategies.”