Thu Sep 18 00:00:00 UTC 2025: Okay, here’s a summary of the text followed by a news article based on it:

**Summary:**

A new study reveals a surprising link between immunity to Japanese Encephalitis Virus (JEV) and the severity of Dengue fever. The study, conducted in Nepal (a country with high JEV immunity due to vaccination but low prior Dengue exposure), found that individuals with moderate levels of JEV antibodies were more likely to experience severe Dengue. This is likely because waning JEV antibodies can, paradoxically, enhance dengue infection. The findings suggest that strategically timed JEV vaccine boosters could potentially mitigate Dengue severity. The study also reinforces the importance of the biomarker chymase in identifying severe dengue cases. The research has significant implications for Asia, where both JEV and Dengue are prevalent, and highlights the interconnectedness of global health challenges.

**News Article:**

**Waning Japanese Encephalitis Immunity Linked to More Severe Dengue Fever, Study Finds**

**New Delhi, September 18, 2025** – A groundbreaking study published in *Science Translational Medicine* reveals a surprising connection between immunity to Japanese Encephalitis Virus (JEV) and the severity of Dengue fever. Researchers from Singapore, Nepal, and the US found that moderate levels of antibodies against JEV can actually *increase* the risk of developing severe Dengue.

The study, conducted during Dengue outbreaks in Nepal between 2019 and 2023, analyzed blood samples from over 500 patients. Nepal provided a unique opportunity for research due to its high JEV vaccination rates and relatively low prior exposure to Dengue. Researchers were able to isolate the impact of JEV immunity.

The study revealed that approximately 61% of patients had pre-existing JEV antibodies. However, those with mid-range antibody levels (titres of 1:160) showed significantly higher levels of chymase, a biomarker associated with severe Dengue. These individuals had a 3x higher risk of developing dengue fever with warning signs.

“These findings echo earlier observations in studies of Zika and dengue viruses, where moderate antibody levels sometimes enhanced the viral infection of immune cells and worsened disease — while very high titres were protective. This is to say, as antibody levels wane over time, populations may enter a vulnerable “middle zone” in which immunity is insufficient to protect but strong enough to enhance disease.” – Authors of the study.

According to Puneet Kumar, a clinician at Kumar Child Clinic, New Delhi, the study reinforces the importance of chymase as a biomarker of dengue fever with warning signs and severe dengue.

The implications are significant for countries like India, where Dengue is on the rise and JEV vaccination programs are in place. Vipin M. Vashishtha, director and paediatrician at Mangla Hospital and Research Center, Bijnor says, “the study strongly suggests the need for suitably timed JE vaccine boosters, which could serve the dual purpose of maintaining durable immunity against JE for longer periods and protecting the population against the risk of dengue fever with warning signs and severe dengue (due to waning titres of anti-JEV antibodies).”

The research underscores the complex interplay between related viruses and highlights the importance of integrated, forward-looking strategies in infectious disease control, especially in a globalized world facing the challenges of climate change and increasing viral spread.

**Note:**
* I’ve followed the style of a news article, including a headline, dateline, and introduction that summarizes the key findings.
* I’ve incorporated quotes from the authors and other experts.
* I’ve emphasized the implications for India.
* I made sure to include the names of the people quoted in the article.

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