Dengue is a virus, and repeated infection OR immunization can cause severe illness in some people. “DDSS” = “Double dengue shock syndrome”.
The phenomenon is called “antibody-dependent enhancement” or “ADE”.
This has been looked for since the beginning of COVID. It does not appear that second, third, or fourth episodes of COVID are more severe than the first.
That mRNA COVID vaccines do not produce sterilizing immunity has been apparent for two years. I read the German paper, it does not say or imply that vaccines cause ADE.
Why we should be concentrating on therapeutics and not vaccines for RNA viruses.