Q&A on one-minute HIV test approval

[Editor's note: With the recent news that the U.S. Food and Drug Administration (FDA) has approved a new HIV test that obtains results within one minute, domestic HIV testing and prevention strategies have a new tool to employ. AIDS Alert asked Philip Bligh, president of bioLytical Laboratories in Vancouver, British Columbia and Chicago, IL, to answer questions in writing about his company's INSTI™ test. His responses are shown in this Q&A story]:

AIDS Alert: BioLytical Laboratories announced on World AIDS Day, Dec. 1, 2010, that it had received FDA approval to market the INSTI™ rapid HIV antibody test in the United States. The test takes one minute to generate results, which makes it much faster than other approved rapid tests, which might take 15 to 30 minutes. How do you think HIV testing sites might use this faster test, and what are the advantages of that 14-29 minutes saved in time spent waiting for results?

Bligh: By eliminating the wait time between performing the test and receiving the results, INSTI offers many advantages, such as higher throughput, increased counseling flexibility, reduced client anxiety, and decreased costs of testing by reducing overall time and logistics and increasing workflow flexibility. Also, it allows testing in novel settings where time is very limited, such as emergency rooms, department of motor vehicle centers, walk-in pharmacy clinics, mass testing events, places of employment, dental offices, and correctional facilities.

Q: The INSTI test's clinical trial data have shown that it has a minimum sensitivity of 99.8% and specificity of 99.5%. How does this compare with other existing HIV tests? Once test results are obtained, how would the HIV testing site follow-up?

A: All of the rapid HIV tests that are FDA approved are extremely accurate, with very comparable rates of sensitivity and specificity. Once the test results are obtained, HIV testing sites should follow their internal procedures of post-test counseling for non-reactive results and for reactive results. All reactive results should be followed up with a confirmatory test and the patient should be referred to appropriate follow-up medical care.

Q: Would you please explain how the INSTI test's unique antigen construct works. How might this test contribute to a multi-rapid test algorithm, and what are the implications?

A: The INSTI rapid HIV test includes a unique antigen construct comprised of recombinant proteins for HIV-1 (gp-41) and HIV-2 (gp-36). Currently this unique antigen is only used in the INSTI test and is not included in any other rapid test on the market. In addition to the unique antigen, INSTI uses a novel flow-through technology platform rather than the traditional lateral-flow platforms utilized by the other rapid tests on the market. When developing a multi-test rapid algorithm, it is important to deploy tests with different antigens and different technology platforms to include tests that are as different from one another as possible. Algorithms will reduce costs, speed up time to results, improve linkage to care and reduce patients lost due to lack of follow-up/returning for confirmatory results. The ultimate benefit will be to increase the number of positives identified and improve linkage to care.

Q: How much will the test cost clinics and other testing sites, and how does this cost compared with available HIV testing options? How might this method be feasible in resource-limited settings?

A: We are quite sensitive to the resource constraints faced by our prospective customers. The list price of INSTI is $9 for the individual test, and $8.50 per test in the 24-pack format. Discounted pricing based on volume, and public health pricing, are available. Biolytical's high-volume, automated manufacturing capability makes INSTI one of the most cost-effective solutions available for providers of HIV rapid testing. The competitive costs for INSTI, combined with the enhanced productivity that I described earlier, should help our customers reduce their overall costs for HIV testing.

Q: Some states in the U.S. still require pre-testing counseling, which sites sometimes have conducted during the testing wait period. How might they cost-effectively implement such counseling with a one-minute test?

A: A one-minute test provides clinicians and counselors with increased flexibility to design pre/post test counseling to better suit the client and the setting. Counselors no longer need to build-in a sometimes artificial, and occasionally stressful 15-20 counseling script to fill time while waiting for test results. Counselors can devote more time to clients that need/want more extensive counseling, and less time to clients who may already be familiar with the script and/or simply want a test result. It's all about enhanced counseling flexibility and tailoring the counseling to the client, not the test kit. Sites can reduce their costs by more efficiently allocating limited counselor/clinician time to clients that need it most.

Q: What are the potential public health implications of the one-minute HIV test?

A: Major public health benefits from INSTI include enhanced access to testing by permitting testing in a much wider variety of novel settings (prisons, ERs, pharmacies, departments of motor vehicles, on-site testing at events, worksite testing, etc.). INSTI also decreases overall testing costs by streamlining counseling, eliminating the need to build new clinics, and by reducing professional overhead due to INSTI's ease of use by task-shifting (using non-medical professionals to reliably conduct the tests). Another implication is reduced stigma associated with screening by making HIV testing more mainstream — when rapid HIV testing can be implemented in more settings, including the novel settings that I described earlier, it can become as ubiquitous and routine as taking a patient's vital signs. Finally, INSTI could help enable the adoption of rapid-rapid algorithms to reduce costs, decrease testing time, minimize clients lost to follow up, expand access to confirmed results and improve linkage to care. Ultimately, the health experts with whom we have collaborated believe that INSTI will lead to improved health outcomes and serve as another tool in the effort to slow the growth rate of the HIV positive population.