Title : Using mathematical models to explore future meningitis vaccination strategies in Ghana
Abstract:
The African meningitis belt, a region which stretches from Senegal to Ethiopia including Ghana, has experienced irregular but periodic epidemics of meningitis, primarily due to Neisseria meningitidis for over a hundred years. The introduction of MenAfriVac, a conjugate vaccine which protects against meningococcal serogroup A (MenA) since 2012 has contributed to a drastic decline in cases due to serogroup A in Ghana. However, cases due to other serogroups of meningococcal meningitis remain a public health challenge in Ghana. The current burden of the disease in Ghana emphasises the need for the upcoming multivalent meningococcal conjugate vaccines (MMCVs) which protect against multiple serogroups (ACWYX). The boosting advantage against MenA due to the MMCVs is important because serogroup A has the potential to rebound as suggested in the previous study. The key question pertaining to the MMCVs’ implementation in this context is the age group to be targeted to best offer this boosting advantage against MenA most efficiently.
The study considered age-specific Susceptible, Carrier, Ill and Recovered (SCIR-type) deterministic models with their vaccinated counterparts. A range of different age targets included 1-29 year olds, 1-19 year olds and 1-14 year olds under different vaccine uptake levels were considered.
For the results, all the proposed vaccine scenarios predicted at least 15 years time to resurgence of MenA following the MMCVs implementation. During this period, the population of carriers can be extremely low. Also, the competing MMCVs implementation approaches predicted a protected population range of approximately (31- 45) % by 2030 against 25% under no MMCVs. These results imply that all the proposed vaccine strategies are shown to be good candidates to be adopted for the MMCVs with better performance under a wider age target.
Hence, the study suggests that further analysis including the possibility of the elimination of MenA is necessary before making policy recommendations.
The study considered age-specific Susceptible, Carrier, Ill and Recovered (SCIR-type) deterministic models with their vaccinated counterparts. A range of different age targets included 1-29 year olds, 1-19 year olds and 1-14 year olds under different vaccine uptake levels were considered
For the results, all the proposed vaccine scenarios predicted at least 15 years time to resurgence of MenA following the MMCVs implementation. During this period, the population of carriers can be extremely low. Also, the competing MMCVs implementation approaches predicted a protected population range of approximately (31- 45) % by 2030 against 25% under no MMCVs. These results imply that all the proposed vaccine strategies are shown to be good candidates to be adopted for the MMCVs with better performance under a wider age target.
Hence, the study suggests that further analysis including the possibility of the elimination of MenA is necessary before making policy recommendations.
