We are interested in sera samples from literally all soil-transmitted helminths and filarial parasites, with a top priority placed on hookworm infected patients, to use sera in screening in immunoassays for vaccine development. Thank you.
It's a long shot, but you could try contacting the authors of these papers on clinical trials. You could also look up the treatments, albendazole, etc. on googls scholar. Some might have samples left.
It is hard to find a regulated repository for serum samples from infected individuals as usually an approval from Ethics Committee is required for any specific purposes. It would be best if you find a collaborator in endemic areas.