Measles seroepidemiology and decay rate of vaccine-induced measles IgG titers in Taiwan, 1995-1997.
Community-based seroepidemiologic studies were conducted to monitor the effectiveness of measles immunization programmes and to estimate the decay rate of vaccine-induced measles IgG titres. Sera collected from a mountain (792 sera), rural (875 sera) and urban (894 sera) populations in 1995-1997 were available. Measles IgG was quantified using a commercial EIA kit. Measles IgG seroprevalence and geometric mean titre (GMT) were calculated by setting the cut-off titre at 50 mIU/ml. The decay rate of measles IgG titres was estimated by assuming that the measles IgG titres, without exposing to wild measles virus, decay exponentially and constantly after 1 year post vaccination. The half-life of measles IgG titres was calculated from the corresponding decay rate. Measles IgG seroprevalences in these three populations have reached >95% in school children (7-18 years old) and >98% in young adults (19-25 years old) but varied from 87 to 96% in pre-school children (4-6 years old). Two-dose vaccinees, comparing with 1-dose vaccinees, had a significantly higher seroprevalence (98 versus 92%, P<0.01) and a slightly longer half-life of measles IgG titres (61 versus 27 months, P=0.08) but the measles IgG GMT in the two groups did not differ significantly (675 versus 618 mIU/ml, P=0.78).
Lee
M S
MS
National Institute of Preventive Medicine (current Center for Disease Control), Department of Health, 161 Kun-Yang Street, Nan-Kang District, 115, Taipei, Taiwan. mslee0007@us.sina.com
Chien
L J
LJ
Yueh
Y Y
YY
Lu
C F
CF
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006207:Half-Life; D006801:Humans; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage / Q000276:immunology*; D008459:Measles virus / Q000276:immunology*; D009500:Neutralization Tests / Q000379:methods; D012424:Rural Population; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology; D014505:Urban Population; D014611:Vaccination
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D008458:Measles Vaccine