A Phase I/II Trial of a Tetravalent Live Attenuated DEN Vaccine in Flavivirus Antibody Naive Children

A Phase I/II, Open, Five-year, Clinical Follow-up Study of Thai Children Who Participated in Dengue-003 ("A Phase I/II Trial of a Tetravalent Live Attenuated DEN Vaccine in Flavivirus Antibody Naive Children") With Evaluation of a Booster Dose Given One Year After Primary DEN Vaccination Series

One year follow-up on immunogenicity and safety of a booster dose of DEN vaccine administered approx. 1 year following the second dose

The purpose of this study is to find out more about the two doses of dengue vaccine, over a five year period, that the children received in the Dengue-003 study and to study a third dose of dengue that will be given to the children

• Do children still have dengue antibodies intended to provide protection against dengue infection one year after the two doses of vaccine given in study Dengue-003?
• Were there any major medical problems that appeared as dengue-like symptoms during the one year after vaccinations?
• Will a third dose of dengue help to further stimulate the part of the immune system intended to help protect against dengue infection?
• Is a third dose as safe as the first two doses?
• Are the local reactions to a third dose of the vaccine similar to what your child experienced after the first two doses?

Inclusion Criteria:

• Subjects who received two doses of DEN vaccine in the Dengue-003 study
• Subjects whos parents signed an informed consent form were eligible for participation in the five year follow-up study

Exclusion Criteria:

• None