Malaria is a serious health problem worldwide affecting mainly children and socially vulnerable people. The biological particularities of P. vivax, such as the ability to generate dormant liver stages, the rapid maturation of gametocytes, and the emergence of drug resistance, have contributed to difficulties in disease control. In this context, developing an effective vaccine has been considered a fundamental tool for the efficient control and/or elimination of vivax malaria. Although recombinant proteins have been the main strategy used in designing vaccine prototypes, synthetic immunogenic peptides have emerged as a viable alternative for this purpose. Considering, therefore, that in the Brazilian endemic population, little is known about the profile of the humoral immune response directed to synthetic peptides that represent different P. vivax proteins, the present work aimed to map the epitope-specific antibodies’ profiles to synthetic peptides representing the linear portions of the ookinete and sporozoite cell passage protein (CelTOS), thrombospondin-related adhesive protein (TRAP), and cysteine-rich protective antigen (CyRPA) proteins in the acute (AC) and convalescent phases (Conv30 and Conv180 after infection) of vivax malaria. The results showed that the studied subjects responded to all proteins for at least six months following infection. For IgM, a few individuals (3–21%) were positive during the acute phase of the disease; the highest frequencies were observed for IgG (28–57%). Regarding the subclasses, IgG2 and IgG3 stood out as the most prevalent for all peptides. During the follow-up, the stability of IgG was observed for all peptides. Only one significant positive correlation was observed between IgM and exposure time. We conclude that for all the peptides, the immunodominant epitopes are recognized in the exposed population, with similar frequency and magnitude. However, if the antibodies detected in this study are potential protectors, this needs to be investigated.

Oral manifestations of HIV infection can be an early sign of the disease and may indicate progression to AIDS. Although antiretroviral therapies, especially highly active antiretroviral therapy (HAART), have reduced the prevalence of HIV-related oral lesions, ongoing updates in diagnosis and treatment are essential due to the extended life expectancy of individuals living with HIV. Periodontal disease is a significant concern in these patients, influenced by altered immune responses and microbial dynamics, though the mechanisms are not fully understood. This exploratory study aimed to investigate the oral microbiota and periodontal disease prevalence in HIV-positive individuals by analyzing subgingival plaque samples from 24 patients. We identified 12 bacterial species using Polymerase Chain Reaction (PCR) and amplicon sequencing. Seven species were detected, with Filifactor alocis, Tannerella forsythia, and Porphyromonas endodontalis being the most common. Porphyromonas gingivalis was present in only 13.6% of samples, while T. forsythia was found in 58.3%. Genetic diversity was also observed in P. endodontalis and Selenomonas sputigena amplicons, with specific single nucleotide polymorphisms (SNPs) identified in both species. These results highlight the complex microbial interactions in the oral environments of people living with HIV, emphasizing the need for personalized diagnostic and therapeutic strategies for managing oral health in this population.