Impact of MenAfriVac on Meningococcal A Meningitis in Cameroon: A Retrospective Study Using Case-by-Case-Based Surveillance Data from 2009 to 2015

Table 2

Impact of MenAfriVac in Cameroon according to the formula of [18].

	Before vaccination (2009–2011)	During vaccination (2012)	After vaccination (2013–2015)
Total CSF	1491	570	1048
Number of N. m A	104	34	1
Risk	0.069751844	0.059649123	0.000954198
Impact (%)	—	14.48	98.63
P value	—	0.41	˂0.0001