Landmark Study Offers New Insights into What Protects Against Dengue

Syllabus: GS2/Health

Context

• A novel study has revealed important insights into developing strong immunity against DENV, which is otherwise quite complex.

About

• Researchers from the US and Philippines have identified specific antibodies, known as envelope dimer epitope (EDE)-like antibodies, as the key for building broad, cross-serotype immunity following natural infection or vaccination.
• The findings represent a significant step forward in understanding dengue immunity and could lead to more effective therapeutics.

About Dengue

• Dengue is a mosquito-borne viral disease caused by the Dengue virus (DENV), which has four serotypes (DENV-1, DENV-2, DENV-3, and DENV-4).
  • It is transmitted primarily by the Aedes aegypti mosquito.
• Spread: The virus does notspread person-to-person directly.
  • A mosquito becomes infected by biting a person already infected with the virus, and then can transmit the virus to another person through a subsequent bite.
• Symptoms: Fever, severe headache, muscle and joint pains, nausea and vomiting, pain behind the eyes, and rashes.
  • In severe cases, the infection can lead to internal bleeding, and if not managed properly, even death.

• Treatment: There is no specific treatment for dengue. Early detection of disease progression with proper medical care lowers fatality rates of severe dengue to below 1%.
• Vaccine: Dengvaxia (CYD-TDV) – approved in some countries, recommended for individuals aged 9-16 with a history of dengue infection.

Dengue & Vaccine Challenges

• Global burden: It is the most common vector-borne viral disease; half the world’s population is at risk, especially in Southeast Asia, Africa, Americas.
  • Dengue fever is one of the top 10 threats to global health, according to the World Health Organisation (WHO).
• Dengue in India: India accounts for a large fraction of global dengue cases; 2.3 lakh cases and 297 deaths were reported in 2024.
• Vaccine challenge: Primary immunity after first infection can worsen disease on second infection with different serotypes.
  • Severe dengue cases (requiring hospitalization) occur after second infections.
  • True protection (secondary immunity) develops only after infection with ≥2 serotypes.

Significance of Study

• EDE-like antibodies could be a biomarker for protective immunity.
• Future vaccines may aim to specifically induce high EDE-like antibody levels.
• Could improve vaccine safety and cross-serotype protection.

Source: TH