Why is there vaccine for dengue?

There is no vaccine. No vaccine has been developed for this illness which is caused by a flavivirus with several different serotypes. Recovery from infection with one serotype does not produce any lasting immunity and one can get repeat infections in the same season.

Related Questions

I need to know if there is a vaccine for dengue fever?

No but... 5 vaccines are currently in clinical trials. Attempts at vaccine have been ongoing since the 1940's; perhaps now, we may finally be close at last. Important question as dengue spikes right now in many countries around the world.. Read more...
Dengue fever vaccine. I live and work in Singapore, which has a high burden of dengue fever. Last season hit us especially hard. We learned last month (June 2014) that Sanofi expects to introduce the world's first dengue vaccine here next year. This is welcomed news, and we hope it will prove to be effective and safe. Read more...

I need to know if there is a vaccine for prevention of dengue fever?

Research. There are no currently available vaccines against dengue. See http://www.Cdc.Gov/dengue/prevention/index.Html for more information. Read more...