New meningitis vaccine protects against epidemic strain

September 11, 2013

One shot of MenAfriVac dramatically reduced incidence of all cases of meningitis by 94% and carriage prevalence of the epidemic strain by 98%, while an epidemic persisted in unvaccinated parts of Chad.

"Until now, it was not known definitively whether MenAfriVac had a major impact on the incidence of serogroup A epidemics and carriage", explains lead author Professor Brian Greenwood from the London School of Hygiene & Tropical Medicine.

"Before this study, mass vaccination campaigns in countries such as Burkina Faso had shown MenAfriVac to be safe and highly effective, resulting in the lowest number of confirmed A cases in over a decade. But in Burkina Faso the vaccine was introduced at a time of falling incidence rates and decreasing transmission, potentially enhancing its true effect and making it difficult to study the vaccine's impact."

This new study by the African Meningococcal Carriage Consortium was designed to compare the effect of MenAfriVac, a meningococcal A conjugate vaccine, on meningitis and meningococcal carriage in vaccinated and unvaccinated regions at the same time during an epidemic.

Deadly epidemics of meningitis A occur regularly in Africa's meningitis belt, a band of 21 countries extending from Senegal to Ethiopia, where around 450 million people are at risk.

The researchers compared incidence rates between individuals aged 1-29 years vaccinated with one dose of MenAfriVac in December 2011 in three regions of Chad (roughly 1.8 million individuals vaccinated) and individuals in the remaining unvaccinated parts of the country.

During the 2012 season, the incidence of meningitis of any kind in the three vaccinated regions was 2.47 per 100 000 (57 cases in the 2.3 million total population), compared with 43.8 per 100 000 (3809 cases per 8.7 million population) in areas without mass vaccination.

What is more, despite enhanced surveillance, not a single group A meningitis case was identified in the three vaccinated regions, while 59 cases were confirmed in unvaccinated areas.

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."

Explore further: Dramatic fall in cases of meningitis A in 3 west African nations after new vaccine introduction

More information: www.thelancet.com/journals/lan … (13)61612-8/abstract

Related Stories

Dramatic fall in cases of meningitis A in 3 west African nations after new vaccine introduction

June 9, 2011
Burkina Faso, Mali, and Niger report the lowest number of confirmed meningitis A cases ever recorded during an epidemic season this year following the successful introduction of a new vaccine that could eliminate the primary ...

Chad says no link between sick kids and meningitis shot

January 22, 2013
Chad's government on Tuesday said a team of international experts have not been able to find any links between the hospitalisation of 38 children and their recent vaccinations against meningitis.

Meningitis A vaccine breaks barrier: First to gain approval to travel outside cold chain

November 14, 2012
Signaling a potential breakthrough for immunization programs in resource-poor countries, researchers today announced at the American Society of Tropical Medicine and Hygiene (ASTMH) conference that regulatory authorities—after ...

WHO eases rules on meningitis vaccine, researchers say

November 15, 2012
In a breakthrough for the fight against meningitis in poor countries, researchers say the WHO has ruled that a key vaccine can be transported or stored for up to four days without refrigeration.

38 children hospitalised after meningitis shot in Chad

January 21, 2013
Thirty-eight children from northern Chad have been hospitalised after being vaccinated for meningitis in a government campaign, the health minister said Monday.

Researchers say step closer to meningitis B vaccine

May 7, 2012
Researchers said Monday they were a step closer to developing a vaccine against the type of meningitis that mostly affects Europe and North America and kills hundreds every year.

Recommended for you

Drug blocks Zika, other mosquito-borne viruses in cell cultures

December 12, 2017
If there was a Mafia crime family of the virus world, it might be flaviviruses.

Study seeks to aid diagnosis, management of catatonia

December 11, 2017
Catatonia, a syndrome of motor, emotional and behavioral abnormalities frequently characterized by muscular rigidity and a trance-like mental stupor and at times manifesting with great excitement or agitation, can occur during ...

New compound stops progressive kidney disease in its tracks

December 7, 2017
Progressive kidney diseases, whether caused by obesity, hypertension, diabetes, or rare genetic mutations, often have the same outcome: The cells responsible for filtering the blood are destroyed. Reporting today in Science, ...

New Lyme disease tests could offer quicker, more accurate detection

December 7, 2017
New tests to detect early Lyme disease - which is increasing beyond the summer months -could replace existing tests that often do not clearly identify the infection before health problems occur.

Spinal tap needle type impacts the risk of complications

December 6, 2017
The type of needle used during a lumbar puncture makes a significant difference in the subsequent occurrence of headache, nerve irritation and hearing disturbance in patients, according to a study by Hamilton medical researchers.

Men with HPV are 20 times more likely to be reinfected after one year

December 5, 2017
A new analysis of genital human papillomavirus (HPV) in men shows that infection with one HPV type strongly increases the risk of reinfection with the same type. In fact, men who are infected with the type responsible for ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.