Live attenuated tetravalent dengue vaccine

Area of Science:

• Virology
• Vaccinology
• Biotechnology

Background:

• Dengue viruses pose a significant global health threat, necessitating effective vaccination strategies.
• Live attenuated vaccines are considered a promising approach for dengue prevention.
• Developing a tetravalent vaccine covering all four serotypes is crucial for comprehensive protection.

Purpose of the Study:

• To develop and evaluate candidate live attenuated dengue vaccines.
• To assess the safety and immunogenicity of monovalent, bivalent, trivalent, and tetravalent vaccine formulations.
• To prepare master virus seeds for industrial-scale vaccine production.

Main Methods:

• Attenuation of dengue virus serotypes 1, 2, and 4 through serial passages in primary dog kidney cells.
• Attenuation of dengue serotype 3 through serial passages in primary African green monkey kidney cells.
• Biological marker studies and clinical trials in Thai and American volunteers to assess safety and immunogenicity.

Main Results:

• Candidate live attenuated dengue vaccines were successfully developed for all four serotypes.
• Vaccine formulations (monovalent to tetravalent) were found to be safe and immunogenic in adult and child volunteers.
• The dengue 2 vaccine candidate induced comparable immune responses in both Thai and American volunteers.

Conclusions:

• Live attenuated tetravalent dengue vaccine candidates are safe and immunogenic.
• The developed vaccine strains are suitable for large-scale production under Good Manufacturing Practice guidelines.
• This research represents a significant advancement towards a globally accessible dengue vaccine.