A cluster-randomized trial of Vi-TT was conducted in Dhaka, Bangladesh, using JE vaccine as the control. A subset of 1,500 children were randomly selected on 2:1 basis (Vi-TT vs JE) to assess immune response. Blood was collected before vaccination, and on days 28, 545 and 730 post-vaccination and plasma anti-Vi-IgG response was measured. A robust, persistent antibody response was induced after single dose of Vi-TT, even after 2 years of vaccination. While there is no accepted serological antibody threshold of protection, analyzing the antibodies of children who received Vi-TT provides evidence that may later be useful in predicting population protection.
Journal article
Vaccine
05/05/2023
41
3137 - 3140
Bangladeshi children, CRT-TCV, Long-term immune response, Humans, Child, Typhoid Fever, Tetanus Toxoid, Salmonella typhi, Vaccines, Conjugate, Bangladesh, Immunoglobulin G, Typhoid-Paratyphoid Vaccines, Antibodies, Bacterial, Vaccination, Antibody Formation