Sierra and colleagues (2012) reported homotypic dengue (DENV-1/2/3) infection increases IL-10 than heterotypic infection. In Tamil Nadu, circulation of DENV-2 was reported till 2017 (Kasirajan et al., 2019), and it is possible that the homotypic DENV-2-infected patient may contribute to the increased IL-10 in DENV-2 DF, while the heterotypic DENV-4 (a naïve population) infection has reduced IL-10. Here, IL10 is linked to infection.