Revaccination With Locally-Produced Vi Typhoid Polysaccharide Vaccine Among Chinese School-Aged Children
| Autor: | John D. Clemens, Leon Ochiai, Zhi-Yi Xu, Jun Zhang, Fengcai Zhu, Hye-Won Koo, Claudia M. Galindo, Yan Chen, Camilo J. Acosta, Lorenz von Seidlein, Jin-kyung Park, Taesung Park, Jacqueline L. Deen, Xuan-Yi Wang, Hua Wang, Weizhong Zhou |
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| Rok vydání: | 2007 |
| Předmět: |
Male
Microbiology (medical) China medicine.medical_specialty Adolescent Immunization Secondary Polysaccharide Vaccine Typhoid fever Double-Blind Method Internal medicine Humans Medicine Typhoid Fever Child Adverse effect business.industry Immunogenicity Polysaccharides Bacterial Typhoid-Paratyphoid Vaccines Vaccination Antibody titer Salmonella typhi medicine.disease Antibodies Bacterial Titer Treatment Outcome Infectious Diseases Immunization Pediatrics Perinatology and Child Health Immunology Female business |
| Zdroj: | Pediatric Infectious Disease Journal. 26:1001-1005 |
| ISSN: | 0891-3668 |
| Popis: | Objective: To evaluate the safety and immunogenicity of revaccination with locally-produced Vi polysaccharide vaccine 3 years after the first dose in Chinese children aged 9 to 14 years. Methods: A randomized, placebo-controlled trial was conducted in Suzhou, Jiangsu, China. Six hundred and sixty-seven eligible children who had previously received a primary dose of Vi vaccine were randomly assigned to receive 1 dose of 30 μg Vi vaccine or placebo. In addition, 331 eligible children received 1 dose of Vi polysaccharide vaccine as a primary vaccination. Adverse events were followed for 28 days after vaccination. Serum samples were collected from a subgroup of participants on day 0 and day 28, and Vi antibodies were analyzed using a passive hemagglutination method. Results: Revaccination was found to be safe and immunogenic. No severe adverse events were observed. A significant increase in antibody titers after vaccination was observed among children who had and had not been previously vaccinated. Twenty-eight days after injection, the seropositive rate was 79% in both revaccination and primary injection groups; the geometric mean antibody titer was 1:40 in the primary injection group and 1:29 in the revaccination group (P = 0.24). Although the difference of attained geometric mean titers in follow-up sera was not significantly different in these 2 groups, the fold-rise of these titers from baseline was significantly higher in the primary injection group than in the revaccination group (7.7 versus 3.1, P < 0.001). Conclusion: We found that revaccination using the locally produced Vi polysaccharide vaccine among Chinese school-aged children was safe and increased antibody titers. Revaccination can be used to extend the duration of protection provided by Vi polysaccharide vaccine. |
| Databáze: | OpenAIRE |
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