Journal of the Pediatric Infectious Diseases Society, Jul 11, 2014
Background. Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean ch... more Background. Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. Methods. Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = 10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. Results. Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). Conclusions. Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation.
The Pediatric infectious disease journal, Dec 15, 2016
Single-dose Hepatitis A Virus (HAV) vaccination was implemented in all Argentinean children aged ... more Single-dose Hepatitis A Virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Previous studies demonstrated high prevalence of protective antibody response 4 years following single dose vaccination. This study assessed long term seroprotection against HAV after vaccination. Children who received one dose of HAV vaccine at 1 year of age at least six years before enrollment were included at five centers in Argentina between 2013 and 2014. Demographic and socioeconomic characteristics were collected through a questionnaire. Blood samples were tested for anti-HAV antibodies. Antibody values ≥10 mIU/mL were considered seroprotective. Logistic regression analysis was done to evaluate association between demographic and socioeconomic variables and seroprotection. 1088 children were included, with a median post-vaccination interval of 7.7 years (range 6.3-9.2 y). From these, 97.4% (95% CI: 96.3%-98.3%) had protective antibodies against HAV. No associati...
Journal of the Pediatric Infectious Diseases Society, Jul 11, 2014
Background. Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean ch... more Background. Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. Methods. Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = 10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. Results. Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). Conclusions. Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation.
The Pediatric infectious disease journal, Dec 15, 2016
Single-dose Hepatitis A Virus (HAV) vaccination was implemented in all Argentinean children aged ... more Single-dose Hepatitis A Virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Previous studies demonstrated high prevalence of protective antibody response 4 years following single dose vaccination. This study assessed long term seroprotection against HAV after vaccination. Children who received one dose of HAV vaccine at 1 year of age at least six years before enrollment were included at five centers in Argentina between 2013 and 2014. Demographic and socioeconomic characteristics were collected through a questionnaire. Blood samples were tested for anti-HAV antibodies. Antibody values ≥10 mIU/mL were considered seroprotective. Logistic regression analysis was done to evaluate association between demographic and socioeconomic variables and seroprotection. 1088 children were included, with a median post-vaccination interval of 7.7 years (range 6.3-9.2 y). From these, 97.4% (95% CI: 96.3%-98.3%) had protective antibodies against HAV. No associati...
Uploads
Papers by María Carrega