TY - JOUR
T1 - Impact of IgM antibodies on cross-protection against pneumococcal serogroups 6 and 19 after immunization with 7-valent pneumococcal conjugate vaccine in children
AU - Cho, Hye Kyung
AU - Park, In Ho
AU - Burton, Robert L.
AU - Kim, Kyung Hyo
N1 - Funding Information:
This study was funded by an RP-Grant 2013 of Ewha Womans University to IHP and KHK and by the Ministry of Food and Drug Safety (11172MFDS360) to KHK. For the remaining authors, none were declared.
Publisher Copyright:
© 2016 The Korean Academy of Medical Sciences.
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Although it is well known that pneumococcal conjugate vaccines provide cross-protection against some vaccine-related serotypes, these mechanisms are still unclear. This study was performed to investigate the role of cross-protective IgM antibodies against vaccinerelated serotypes 6A, 6C, and 19A induced in children aged 12-23 months after immunization with 7-valent pneumococcal conjugate vaccine (PCV7). We obtained serum samples from 18 Korean children aged 12-23 months after a PCV7 booster immunization. The serum IgG and IgM concentrations of serotypes 6B and 19F were measured by enzymelinked immunosorbent assay (ELISA) in serum. The opsonic indices (OIs) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were determined by an opsonophagocytic killing assay (OPA) in IgM-depleted and control serum. Both IgG and IgM antibodies in ELISA and opsonic indices in OPA against serotypes 6B and 19F were demonstrated in the immune serum. IgM depletion decreased the OIs against vaccine serotypes 6B (geometric means of OIs (GMIs) of 3,009 vs. 1,396, 38% reduction) and 19F (1,117 vs. 750, 36% reduction). In addition, IgM depletion markedly decreased the OIs against vaccine-related serotypes 6A (GMIs of 961 vs. 329, 70% reduction), 6C (432 vs. 185, 72% reduction), and 19A (301 vs. 166, 58% reduction). The booster immunization PCV7 induced protective antibodies in the form of both IgG and IgM isotypes. IgM antibodies contributed to eliciting cross-protection against vaccine-related serotypes as well as against vaccine serotypes.
AB - Although it is well known that pneumococcal conjugate vaccines provide cross-protection against some vaccine-related serotypes, these mechanisms are still unclear. This study was performed to investigate the role of cross-protective IgM antibodies against vaccinerelated serotypes 6A, 6C, and 19A induced in children aged 12-23 months after immunization with 7-valent pneumococcal conjugate vaccine (PCV7). We obtained serum samples from 18 Korean children aged 12-23 months after a PCV7 booster immunization. The serum IgG and IgM concentrations of serotypes 6B and 19F were measured by enzymelinked immunosorbent assay (ELISA) in serum. The opsonic indices (OIs) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were determined by an opsonophagocytic killing assay (OPA) in IgM-depleted and control serum. Both IgG and IgM antibodies in ELISA and opsonic indices in OPA against serotypes 6B and 19F were demonstrated in the immune serum. IgM depletion decreased the OIs against vaccine serotypes 6B (geometric means of OIs (GMIs) of 3,009 vs. 1,396, 38% reduction) and 19F (1,117 vs. 750, 36% reduction). In addition, IgM depletion markedly decreased the OIs against vaccine-related serotypes 6A (GMIs of 961 vs. 329, 70% reduction), 6C (432 vs. 185, 72% reduction), and 19A (301 vs. 166, 58% reduction). The booster immunization PCV7 induced protective antibodies in the form of both IgG and IgM isotypes. IgM antibodies contributed to eliciting cross-protection against vaccine-related serotypes as well as against vaccine serotypes.
KW - Heptavalent pneumococcal conjugate vaccine
KW - Immunoglobulin M
KW - Pneumococcal polysaccharide type 19
KW - Pneumococcal polysaccharide type 6
KW - Streptococcus pneumoniae
UR - http://www.scopus.com/inward/record.url?scp=84965036072&partnerID=8YFLogxK
U2 - 10.3346/jkms.2016.31.6.950
DO - 10.3346/jkms.2016.31.6.950
M3 - Article
C2 - 27247505
AN - SCOPUS:84965036072
SN - 1011-8934
VL - 31
SP - 950
EP - 956
JO - Journal of Korean Medical Science
JF - Journal of Korean Medical Science
IS - 6
ER -