Persistence of anti-HBs 5 years after the introduction of routine infant and adolescent vaccination in Italy.
A population survey was conducted to assess the duration of anti-HBs levels > 10 IU/l in vaccinees living in Lazio Region (Italy) 5 years after the introduction (15 June 1991) of compulsory vaccination of new-borns and 11-year-old children. A random sample of 1192 (533 children born in 1991--92 and 659 adolescents born in 1979--81) was selected. In 92.9% of children and 94.1% of adolescents anti-HBs titres were protective (> or = 10 IU/l). These subjects with protective titres were divided into three categories: low responders (anti-HBs titres = 10--500 IU/l), medium responders (anti-HBs titres = 501--2000 IU/l) and high responders (anti-HBs titres > 2000 IU/l). Factors associated with the level of response were analysed, using a multiple politomic logistic regression analysis. Greater age at first dose (11--12 years) was associated with higher titres (OR = 2.1, 95% CI = 1.4--3.2 for medium responders and OR = 3.0, 95% CI = 1.9--4.8 for high responders). Simultaneous administration of DT vaccine was associated with lower titres (OR = 0.4, 95% CI = 0.2-0.8 for medium responders and OR = 0.3, 95% CI = 0.1--0.7 for high responders).
Department of Epidemiology, Lazio Region Health Authority, Via S. Costanza 53, 00198 Rome, Italy. malinfl@asplazio.it
A
A
Faustini
E
E
Franco
M
M
Sangalli
T
T
Spadea
R M
RM
Calabrese
M
M
Cauletti
C A
CA
Perucci
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D007231:Infant, Newborn; D007558:Italy; D015999:Multivariate Analysis; D013997:Time Factors; D014611:Vaccination
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines