Flavivirus-induced antibody cross-reactivity

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Dengue virus (DENV) and West Nile virus (WNV) are significant human pathogens with no licensed vaccines.
• Existing vaccines target other flaviviruses, prompting investigation into cross-reactivity.
• Understanding flavivirus cross-reactivity is crucial for developing broad-spectrum vaccines.

Purpose of the Study:

• To investigate flavivirus cross-reactivity using sera from individuals vaccinated against multiple flaviviruses.
• To map the antigenic relationships between various flaviviruses, including WNV, DENV, TBEV, JEV, YFV, and LIV.
• To assess the impact of prior vaccinations on antibody responses to different flaviviruses.

Main Methods:

• Sera from a human cohort vaccinated against TBEV, JEV, and YFV were tested for neutralizing antibodies.
• Plaque reduction neutralization tests were employed to quantify antibody titers.
• Antigenic cartography techniques were utilized to visualize flavivirus antigenic relationships.

Main Results:

• Sera showed neutralization of louping ill virus (LIV) and, in some cases, WNV and DENV-2.
• YFV vaccination enhanced WNV neutralization in some recipients.
• Antigenic cartography revealed individual variations in antibody responses and confirmed close antigenic relationships between TBEV and LIV, and TBEV and JEV.

Conclusions:

• Vaccination against certain flaviviruses can elicit cross-neutralizing antibodies against other flaviviruses like WNV and DENV.
• Antigenic cartography is a valuable tool for illustrating complex flavivirus antigenic relationships and individual immune responses.
• Significant differences exist between amino acid sequence identity and mapped antigenic relationships within the Flaviviridae family.