HIV testing in the context of long-acting extended delivery of HIV PrEP

SY11

Symposium

Track C - Epidemiology and prevention science

CME accreditation

M3/Channel 5

25 July 10:30 - 11:30

Moderators

Philip CUNNINGHAM
St Vincents Hospital Sydney Limited, Australia
Beatriz GRINSZTEJN
Fiocruz/INI, Brazil

Recent CAB LA trials have shown that long-acting extended delivery (LAED) of PrEP suppresses viral replication, delaying seroconversion and making HIV diagnosis with conventional diagnostics challenging. Delays in diagnosis can lead to ART resistance. While the addition of HIV viral load (VL) testing could address this challenge, implementation of HIV VL testing in LMIC settings where PrEP need is high is likely to be costly and challenging. While there are efforts to develop point-of-care viral load assays, these may not be sufficiently sensitive to detect low levels of viremia in the context of PrEP use. This symposium will: 1) review what is known about HIV diagnosis in the context of LAED; 2) review new developments in HIV diagnostics and self-testing; and 3) locate these developments in the context of implementation research priorities for CAB LA and future LAED.

10:30 5 min	Introduction Philip CUNNINGHAM St Vincents Hospital Sydney Limited, Australia Beatriz GRINSZTEJN Fiocruz/INI, Brazil

10:35 10 min	HIV testing approaches: Current and new approaches and considerations for long-acting PrEP Lucia HANS National Health Laboratory Service, South Africa

10:45 10 min	Long-acting PrEP and the potential for resistance Urvi PARIKH University of Pittsburgh, United States

10:55 10 min	Long-acting PrEP: Programmatic considerations for HIV testing Jason REED Jhpiego, United States

11:05 25 min	Live Q&A Philip CUNNINGHAM St Vincents Hospital Sydney Limited, Australia Beatriz GRINSZTEJN Fiocruz/INI, Brazil Lucia HANS National Health Laboratory Service, South Africa Urvi PARIKH University of Pittsburgh, United States Jason REED Jhpiego, United States

AUTHOR

Katherine Gill

SUMMARY

Trials demonstrate that long-acting PrEP suppresses viral replication making HIV diagnosis challenging in this context and leading to possible resistance This symposium reviewed what is known about HIV diagnosis, highlighted new developments in diagnostics and self-testing and located these developments in the context of implementation research priorities for injectable PrEP.

HIGHLIGHTS

Urvi Parikh stressed that while resistance is a concern when using long-acting PrEP this should not delay the rollout of new HIV prevention technologies. The Dapivirine ring has low resistance risk because of low systemic drug levels in contrast to the high risk of acquiring resistance if diagnosis is delayed using CAB LA. The MOSAIC study will monitor resistance in users of dapivirine ring and CAB LA in implementation projects in Kenya and the US. Jason Reed highlighted that HIV rapid tests often fail to detect HIV infection in the setting of CAB-LA and this delayed expression can persist for months even after injections are discontinued, leading to resistance. Nucleic acid testing allows for earlier detection but may not be feasible in all settings. Scale-up projects will need to share information to inform routine delivery and fill evidence gaps. Lucia Hans presented current and new approaches to HIV diagnostic testing. WHO recommends the use of antibody tests and not nucleic acid tests for HIV diagnosis while CDC recommends HIV-RNA testing for people who have received CAB-LA in preceding 12 months. Access to viral load testing is sub-optimal in most countries and turnaround time and expense may limit this option.

CRITICAL ASSESSMENT

Long-acting PrEP is being introduced in a number of scale-up projects around the world. HIV diagnosis in the context of long-acting PrEP may be challenging. Optimal HIV testing strategies need to be established to support integration within existing services and are not currently known. The risk of potential drug resistance must be balanced with the benefits of wider CAB-LA access and decreasing new infections.