[Effectiveness of an immunization campaign with group A and C meningococcal polysaccharide vaccine in controlling an outbreak of group C meningococcal disease].
OBJECTIVE
To assess the safety, immunogenicity and efficacy of group A and C meningococcal polysaccharide vaccine (A/C MPV) in response to an outbreak of group C meningococcal disease.


METHODS
A vaccination campaign with A/C MPV was prompted 6 weeks after the use of group A MPV in Laibin city, Guangxi, where an outbreak of group C meningococcal meningitis occurred in 2002. Vaccinees were observed for local and systemic reactions after the vaccination and followed up for the meningococcal disease for 5 years. Blood samples were collected from 71 people in the epidemic and 43 in the non-epidemic areas before and 1 month after the vaccination and examined by ELISA to detect IgG antibodies to group A and C polysaccharides.


RESULTS
The vaccination coverage was 97%. No significant adverse reactions were observed. The positive rates of group C antibodies after vaccination was between 97.67% and 100% among the populations in the epidemic and non-epidemic areas, as well as among those negative and positive for group C antibodies prior to the vaccination. The geometric mean anti-C concentrations ranged 30.81 microg/ml to 37.44 microg/ml, showing no significant difference between groups. The incidence rate of meningococcal disease in students with timely immunization (218.58/100,000) dropped by 69.02%, when compared to that in those with delayed immunization (705.72/100,000). No clinical cases were identified during the follow-up period of 15,760 person-years.


CONCLUSIONS
The vaccination campaign with the Chinese group A/C MPV seemed successful in controlling the group C meningococcal outbreak. The vaccine was shown to be safe even administered after the group A vaccine only 6 weeks apart. It could induce high levels of antibodies in vulnerable population and significantly increase antibody levels in seropositive individuals, thus providing a protection of at least 5 years.
Gong
Jian
J
Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning 530028, China.
Li
Cui-Yun
CY
Dong
Bai-Qing
BQ
Huang
Jing-Zhi
JZ
Quan
Yi
Y
Lu
Wan-Zhuan
WZ
Luo
Cheng-Hui
CH
Mao
Wei-Cheng
WC
Liao
He-Zhuang
HZ
Fang
Jin-Song
JS
Cui
Xuan-Lin
XL
Xie
Gui-Lin
GL
Wu
Xing-Hua
XH
Lan
Rong-Wei
RW
D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D032541:Mass Vaccination; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000145:classification / Q000627:therapeutic use*; D016896:Treatment Outcome
D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines