AsianScientist (Oct. 14, 2025) – Dengue is a extremely prevalent viral illness transmitted by Aedes mosquitoes, infecting as much as Signs vary from fever and rash to life-threatening bleeding or organ failure. To make issues worse, 4 completely different variations—or serotypes—of the virus imply an individual could be contaminated as much as 4 occasions in a lifetime.
Vaccines exist, however they defend individuals who have already had dengue. Even then, scientists are puzzled over why two doses of vaccine don’t match the immunity gained from one pure an infection.
Researchers at Duke-NUS Medical Faculty on the Nationwide College in Singapore, working with worldwide collaborators, have uncovered a elementary distinction between the physique’s pure response to dengue an infection and the immunity triggered by vaccination. In a examine printed in Med, they present that dengue an infection doesn’t simply set off an immune response and fade away. As an alternative, it reprogrammes the immune system, leaving an enduring genetic imprint. This impact, they discovered, doesn’t happen with vaccination.
To research, the scientists ran a scientific trial administering two TAK-003 dengue vaccine doses 90 days aside in 26 volunteers in america and analysed 50 extra blood samples from Singapore. Via superior gene expression profiling, the workforce discovered that, even earlier than vaccination, individuals who had recovered from dengue carried distinct patterns of gene exercise. This “imprint” was not within the anticipated antibody-producing reminiscence B cells, however within the very innate immune cells—monocytes and dendritic cells—that the dengue virus targets.
“This reveals that pure dengue an infection can go away an enduring genetic imprint on the immune system,” mentioned first writer Eugenia Ong, principal analysis scientist at Duke-NUS. “As an alternative of returning to regular, the immune system resets into a brand new baseline, one which will clarify why second infections are sometimes extra extreme.”
This long-term rewiring, often known as “skilled immunity”, has been noticed in malaria and after sure vaccines like BCG, however by no means in dengue. It implies that after an infection, the immune system doesn’t merely reset to manufacturing unit settings. As an alternative, it installs a brand new baseline that influences each response thereafter.
The distinction additionally explains why vaccines behave otherwise relying on an infection historical past. For dengue-naïve people, two doses act like gentle warm-ups. For these with prior an infection, one vaccine dose triggers a far stronger response as a result of the immune system has already been “skilled”.
“Consider it as coaching for a sport,” defined Ooi Eng Eong, senior writer and researcher at Duke-NUS’ Rising Infectious Ailments Programme. “The immune system solely will get an actual exercise from the total recreation, which is the equal of a pure an infection. A lightweight warm-up from vaccination will not be sufficient to reprogram it.”
The discovering clarifies why two vaccine doses don’t equal the safety conferred by one prior an infection and sheds gentle on secondary dengue pathogenesis: a reset baseline that mutes antiviral defences can mix with antibody results to worsen outcomes in some folks.
“As dengue continues to have an effect on thousands and thousands throughout Asia, Latin America and different tropical areas, this examine closes a important hole in our understanding of how an infection reshapes the immune system,” mentioned Professor Patrick Tan, a senior writer of the examine and vice-dean for analysis at Duke-NUS. He famous the perception might inform vaccine design and coverage.
The researchers hope their findings will encourage new approaches to dengue prevention. Whereas an ideal vaccine should be years away, the proof reveals that even imperfect ones could be deployed safely to curb the estimated 100 million annual circumstances worldwide.
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Supply: Duke-NUS Medical Faculty; Picture: Freepik
This text could be discovered at: Dengue Virus An infection Reprograms Baseline Innate Immune Gene Expression
Disclaimer: This text doesn’t essentially mirror the views of AsianScientist or its employees.
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