HIV SeropositivityHIV SeroprevalenceHIV InfectionsSubstance Abuse, IntravenousVaccinesSexual BehaviorRisk FactorsSeroepidemiologic StudiesVaccines, InactivatedViral VaccinesVaccines, CombinedVaccines, DNAVaccines, SyntheticBacterial VaccinesAIDS VaccinesAntibodies, ViralVaccines, SubunitVaccines, ConjugateVaccinationAntibodies, BacterialMalaria VaccinesPapillomavirus VaccinesImmunoglobulin GMeningococcal VaccinesHepatitis B VaccinesEnzyme-Linked Immunosorbent AssayMeasles VaccineChlamydophila pneumoniaePertussis VaccineHaemophilus VaccinesBCG VaccineChlamydophila InfectionsPoliovirus Vaccine, InactivatedRabies VaccinesSerologic TestsRotavirus VaccinesCholera VaccinesHepatitis A VaccinesMeasles-Mumps-Rubella VaccineHIV SeronegativityTyphoid-Paratyphoid VaccinesSmallpox VaccineImmunization, SecondaryTuberculosis VaccinesImmunization SchedulePrevalenceChickenpox VaccineDiphtheria-Tetanus-Pertussis VaccineMumps VaccineAdjuvants, ImmunologicHelicobacter pyloriHIV-1Helicobacter InfectionsRubella VaccinePapillomavirus InfectionsAntigens, BacterialStreptococcal VaccinesAnthrax VaccinesDengue VaccinesVaccines, VirosomeToxocariasisAntibodies, NeutralizingCytomegalovirus InfectionsImmunizationHerpesvirus 2, HumanViral Hepatitis VaccinesAntibodies, ProtozoanAcquired Immunodeficiency SyndromePoliovirus Vaccine, OralInfluenza, HumanYellow Fever VaccineCross-Sectional StudiesPlague VaccineFungal VaccinesToxoplasmosisSAIDS VaccinesHemagglutination Inhibition TestsVaccines, AcellularHuman papillomavirus 16ToxocaraCase-Control StudiesHepatitis AAIDS SerodiagnosisHerpes GenitalisMice, Inbred BALB CHepatitis CSalmonella VaccinesBlood DonorsVaccines, Virus-Like ParticleNeutralization TestsHepatitis BEbola VaccinesHepatitis A Virus, HumanImmunoglobulin MBrazilAntibodies, HelminthRural PopulationHIV AntigensAge FactorsNeospora