The present and future for combination prevention for HIV sexual transmission

Monday afternoon Bridging session: The present and future of combination prevent for HIV sexual transmission. 

Thanks to the ’How do you like your PreP’ session in the neighbouring room, this session was poorly attended but highly interesting and relevant.

Five speakers gave different perspectives on HIV prevention strategies amongst varying populations. 

The overarching message was about a paradigm shift in HIV prevention away from an ‘insufficient’ ‘condom protection (CP)’ based message to a more ‘realistic’, nuanced and individualistic combination-prevention model which should demonstrate flexibility and adhere to cultural and community ethics (a bit vague… but prioritise making the prevention relevant to the person/population you are treating) 

A stand-out and, perhaps, more locally relevant talk was  given by Andrew Grulich. 

He specifically discussed the combination prevention strategies ‘TasP’ and ‘PreP’  in MSM. 

He reminded the audience that HPTN 052 included only 2% MSM and there are yet to be ‘published’ findings on ‘TasP’ in sero-different MSM couples. Despite this, in HPTN 052, no index-to-partner transmissions were observed if viral suppression was achieved. 

The “PARTNER” study and “Opposites Attract” will ultimately aim to quantify this in MSM and the preliminary results appear at least as promising as HPTN 052 (zero linked transmissions to date in Opposites Attract).

PreP however has clearly demonstrated very high efficacy in MSM in iPrex, PROUD and Ipergay. Andrew proposed PreP as being a ‘missing link’ in the combination prevention intervention strategies and highlighted this with an example of new HIV diagnoses across three comparable MSM populations in Sydney, London and San Francisco. PreP is readily accessible in SF and less readily available as a prevention strategy in Sydney and London. 

Whilst the number of HIV diagnoses may not necessarily represent a true increase in HIV incidence, San Francisco is the only setting to see a substantial decline in HIV since the introduction of PreP. 

This decrease is  despite increasing rates of condomless anal intercourse in MSM and increasing rates of and STIs in San Francisco compared with Sydney and London.