Indian scientists at the government-run Translational Health Science and Technology Institute (THSTI) have found that the outbreak of Covid-19 has a significant impact on the spread of severe dengue cases. The study, which is yet to be peer-reviewed, demonstrated that Covid antibodies can cross-react with the dengue virus serotype, largely improving dengue infection.

According to data from the National Centre for Vector Borne Diseases Control (NCVBDC), 303 patients succumbed to Dengue in 2022. Dengue is a vector-borne disease that has been prevalent in the country, with a surge of more than 1,312% since the initial significant outbreak in 1996. The incidence of dengue hemorrhagic fever and dengue shock syndrome continues to be a threat as it causes fatalities.

Antibodies against SARS-CoV-2 showed cross-reactivity with DENV-2, a dengue-causing virus serotype, according to the analysis by 24 authors of THSTI – an autonomous institute under the Department of Biotechnology, Ministry of Science and Technology.

A preprint study has found that antibodies against SARS-CoV-2 can cross-react with a dengue virus serotype and increase its infection via antibody-dependent enhancement. These antibodies, whether obtained from natural human infection or experimental animal immunization, had the capacity to boost dengue infection in animal cells.

According to a top government scientist, who did not wish to be named, the dengue virus in India has undergone significant evolution over the last few decades, as it adapts to various selective forces, potentially resulting in the emergence of new variants.

Before 2012, the most common strains of dengue virus in India were DENV 1 and 3. However, in recent years, DENV 2 has become the dominant strain throughout the country, and even DENV 4, which was previously considered less infectious, is now establishing a presence in South India.

The latest surge in cases prompted the study. Dengue disease is highly prevalent in tropical and subtropical regions worldwide, but its pathogenesis is still not fully understood, especially when compared to other endemic viruses. This lack of understanding makes dengue a deadly disease.