A Survey of Serum Bactericidal Antibodies against Neisseria meningitidis Serogroups A, C, W and Y in Adolescents and Adults in the Republic of Korea.
BACKGROUND
This descriptive epidemiological study aimed to assess the prevalence of serum bactericidal antibodies against Neisseria meningitidis serogroups A, C, W and Y in adolescents and adults in the Republic of Korea.


METHODS
In total, 987 subjects aged 11-55 years from five geographical regions of Korea were included in the study. Human serum bactericidal assay (hSBA) was used to measure hSBA titres for serogroups A, C, W and Y. Percentages of subjects with hSBA titres ≥4 and ≥8, geometric mean titres (GMTs), and associated 95% confidence intervals (CIs), were estimated. Analysis was performed for the entire study population and stratified by age group or region. No statistical hypotheses were tested.


RESULTS
The highest percentage of subjects with hSBA titres ≥8 was observed for serogroup W (74%), was similar for serogroups C (34%) and Y (36%), and was lowest for serogroup A (9%). The percentages of subjects with hSBA titres ≥4 were similar to those with hSBA titres ≥8 for all serogroups. GMTs were 2.56 µg/mL (serogroup A), 5.14 µg/mL (serogroup C), 22.63 µg/mL (serogroup W) and 5.28 µg/mL (serogroup Y). Similar trends in GMTs across serogroups were seen for individual regions and age groups. The highest GMTs for serogroups A, W and Y were recorded in the >19-29 years group, and for serogroup C in the >49-55 years group. Across all regions, GMTs were very similar for serogroups A, C and Y, while more variation was seen for serogroup W.


CONCLUSIONS
In the Korean population, among Neisseria meningitidis serogroups A, C, W and Y, serum bactericidal antibodies were most prevalent against serogroup W and least prevalent against serogroup A. These trends were maintained across age groups and regions. The highest GMTs for serogroups A, W and Y were observed in the >19-29 years group. The reasons behind the observed differences in prevalence of bactericidal antibodies against the serogroups are currently not understood, although carriage and cross-reactivity of the assay may be important influences.
Department of Pediatrics, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
Jin-Han
0000-0003-1610-6742
JH
Kang
GlaxoSmithKline BV, Amsterdam, The Netherlands.
Yan
0000-0002-7728-3112
Y
Miao
Department of Pediatrics, Incheon St.Mary's Hospital, The Catholic University of Korea, Incheon, Korea.
SooYoung
0000-0002-5354-3135
S
Lee
Department of Pediatrics, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
Jong-Hyun
0000-0001-8641-7904
JH
Kim
Department of Pediatrics, Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea.
Kyung-Yil
0000-0001-6510-1580
KY
Lee
Department of Pediatrics, Changwon Fatima Hospital, Changwon, Korea.
Sang Hyuk
0000-0002-4835-9704
SH
Ma
Department of Pediatrics Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Korea.
Dae Sun
0000-0002-3141-9539
DS
Jo
Novartis Korea Ltd, Seoul, Korea.
HyoYoung
0000-0001-7121-7475
H
Song
Seqirus Netherlands BV, Amsterdam, the Netherlands.
Mendel
0000-0001-7895-7556
M
Haag
Adolescents; Adults; Epidemiology; Neisseria meningitidis; Republic of Korea; Serogroups; Serosurveillance; hSBA