PvCSP sequences from 34 P. vivax-infected patients in Southern Thailand were compared with 281 public sequences from Brazil and Vanuatu. IEDB predictions mapped T-cell epitopes against prevalent Thai HLA alleles. Conserved N- and C-terminal regions contained dense CD4+ and CD8+ targets, and cumulative modelled population coverage reached 95.86% in Southeast Asia. These are vaccine-design candidates, not observed immunogenicity or protection.
Key findings
- The cumulative predicted epitope set achieved 95.86% modelled population coverage in Southeast Asia.
- Predicted CD4+ and CD8+ epitopes clustered in conserved N- and C-terminal regions, while the central repeat region contained limited predicted CD4+ targets.
- Nine amino-acid residues in predicted class I and II HLA-restricted epitopes were conserved across the compared sequences.
Why this matters globally
P. vivax elimination is hindered by relapsing liver stages and the absence of a licensed vaccine. Conserved, regionally relevant targets can prioritise peptides, but measured T-cell responses and protection must be demonstrated before clinical development.
Thai researcher contribution
Mahidol University researchers generated sequence evidence from Southern Thai patients and connected it with regional HLA diversity, working with international collaborators on the global comparison.
Limitations to consider
This is immunoinformatic prediction, not measured peptide-HLA binding, T-cell immunogenicity or vaccine efficacy. The Thai sample was 34, with public comparator sequences described from Brazil and Vanuatu. The 95.86% value is modelled coverage, not protection.