AEGiS-15IAC: [LbOrC19] HIV-1 STRAINS IN CHON BURI / RAYONG PROVINCES AND THEIR RELATIONSHIP TO THE PHASE III VACCINE TRIAL STRAINS

15th International AIDS Conference

Bangkok, Thailand — July 11-July 16, 2004

[LbOrC19] HIV-1 STRAINS IN CHON BURI / RAYONG PROVINCES AND THEIR RELATIONSHIP TO THE PHASE III VACCINE TRIAL STRAINS

Int Conf AIDS. 2004 Jul 11-16;15:Abstract No. LbOrC19

V Watanaveeradej¹, M Benenson², M de Souza², S Nitayaphan³, N Sirisopana³, B Kim⁴, P Renzullo⁴, E Sanders-Buell⁴, A Brown⁵, S Tovanabutra⁴, J McNeil⁶, D Birx⁶, J Carr⁴, F McCutchan⁴
¹Phramongkutklao Hospital, Bangkok, Thailand; ²Henry M Jackson Foundation, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand; ³Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences , Bangkok, Thailand; ⁴Henry M Jackson Foundation, Rockville, United States; ⁵US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand; ⁶Walter Reed Army Institute of Research, Rockville, United States

BACKGROUND: The molecular epidemiology of HIV-1 in candidate populations for a Prime-boost (ALVAC-AIDSVAX) Phase III Trial was studied and the protein distances of the circulating strains with the prototype E (CRF01) and B components in the vaccine were compared.

METHODS: Community cohorts in Chon Buri and Rayong, the provinces of Thailand, were studied between 1998-2001. Sera from HIV sero-prevalent cases were screened by Multi-region Hybridization Assay (MHAbce). PBMC DNA from the prevalent cases with discordant subtype results by MHA and most of incident cases (90%) were subjected to full-genome sequencing and the sequences were phylogenetically analyzed. Translated protein sequences of the characterized HIV-1 strains were compared to the vaccine prototype B and CRF01 strains.

RESULTS: MHAbce of 168 prevalent serum samples revealed 151 (89.9%) CRF01, 4 (2.4%) B, 8 (4.7%) CRF01/B recombinants and 5 (3.0%) putative dual infections. Full genome analysis of 7 prevalent cases identified 3 CRF01, 1 B, 1 CRF01/B unique recombinant form (URF CRF01/B), 1 CRF15_01B and 1 URF CRF01/C. Twenty-one genomes were recovered from 20 incident cases (1 was dually infected with CRF01 and URF CRF01/B); 19 CRF01, 1 B and 1 URF CRF01/B were identified.

For ALVAC, the pair-wise protein distances to B_LAI gag-protease had a mean of 7.9+4.3% and distances to B_LAI gp41 had a mean of 14.3+7.8%. Gp120 of TH023 (CRF01) was not available for comparison. For AIDSVAX B/E gp120, 2 B and 1 URF CRF01/B were compared with B_MN and the mean protein distance was 20.3+2.0%. All CRF01 sequences were compared with CRF01-CM244 and the mean distance was 13.0+3.8%.

CONCLUSIONS: The majority circulating strain is CRF01_AE. Candidate populations for the Phase III trial do contain CRF01/B and CRF01/C recombinant strains as well as dual infections. Relationships to vaccine strains reflect both subtype distribution and relative conservation of genes.

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