Why secondary dengue infection more virulent?

[scilearner]

If u get infected with X serotype of dengue. And then you get infected again with Y serotype you get a severe infection. What is the exact pathology behind this. Also what happens if you get infected by X serotype again, do you get severe infection then as well. Thanks

[whusean]

Hi,

 

If you get infected with the X serotype and survive, you will likely become immune to serotype X. Therefore further X infection will unlikely result in clinical symptoms. Serotype Y would be marked with a varying antigenic profile (compared to X), therefore infection with Y will mean that the person will become ill as the immune system has had no prior encounter with Y. The reason why secondary infections are more virulent is because of a process called antibody-dependent enhancement (ADE). Your better of googling ADE because its quite complex, and i cant really be bothered to explain it all.

 

Regards

[scilearner]

Thanks you got me in right track