The finding of Plasmodium vivax (a parasite) in your blood confirms the diagnosis of malaria. This organism is usually transmitted by the bite of Anopheles mosquitoes but can be transmitted by blood transfusion as well. The vivax form of the parasite is one which can replicate in the liver so that there can be recurrent attacks of malaria. The way to treat this infection is for 2 weeks with a combination of chloroquine and primaquine which is what I assume you were prescribed.
A recurrence may indicate that either the parasite was not completely eliminated as when it is resistant to the medication prescribed or that it was not a true recurrence and that you got re-infected. In certain countries including India, chloroquine resistant parasites are emerging. If this be the case you will need to be treated by different medications. In order to prevent a re-infection in case you get bitten by an infected mosquito again, you should apply a mosquito repellant, wear long sleeved shirts and long pants especially at dusk when these mosquitoes are most active and you should sleep under a mosquito net. There is no vaccine available at the present time although many researchers are working on developing one.