The quest for an effective vaccine and when it will be available are questions that have been in much public debate since the COVID-19 pandemic started in February of this year. Nine months on, and while the vaccine development process has advanced in leaps and bounds, the answers to these key questions of effectiveness and availability remain unknown. In this time of uncertainty it is clear that testing for COVID-19 will remain a key part of the strategy to manage the virus.
If you are one of the tens of thousands of Australians who have had a test for COVID-19 it is almost certain that your test sample will have been processed and analysed in a public or private laboratory with your results returned to you in 1-2 days. The consensus is that apart from a few local hiccups, testing in Australia has proceeded well through scientific ingenuity, professional expertise and reliable instrumentation.
However just like the quest for a vaccine those involved in the medical or diagnostic testing industry and profession are also urgently seeking ways to provide more rapid testing, with COVID-19 results in minutes or hours rather than days. The media occasionally carries reports about this quest such as the one in early October which described, albeit without much detail, on a testing method to be deployed at Heathrow airport to rapidly test inbound passengers.
It is not difficult to think of other areas where there would be undoubted benefits from being able to both test people more conveniently i.e. closer to their home or work location and to provide more rapid results. Several papers in the medical literature make the case for where such point-of-care testing could be deployed (1,2).
Point-of-care testing for COVID-19 is already being used in Australia, including in the aboriginal communities, as was highlighted on these pages in May of this year. In this case the technology is supplied by an international company but several organisations in Australia are also working on innovative ways to provide more rapid COVID-19 testing using similar molecular technologies to those in the main pathology laboratory.
One of these innovators is Lab Without Walls, a not for profit organisation committed to developing infectious disease testing for remote areas. As part of a consortium involving PathWest (the public pathology network in WA), Gene Target Solutions and Scientific Partners Australia, they have developed a novel portable workflow system instrument capable of providing 36 patient results in 2.5-3.0 hours from receipt of swabs to provision of results. Their Co-Diagnostics Logix Covid -19 test kit has subsequently been certified and listed in the Australian Register of Therapeutic Goods.
A different approach to rapid testing appeared this month with the availability of rapid antigen tests for COVD-19. These still require a nasal swab but the sample after some preliminary treatment, is then immediately applied to a small hand-held strip. Within the strip are various chemicals including antibodies which detect the antigens from the COVID-19 virus. After 15-30 minutes the strip indicates whether the virus is present or not.
Some considerable debate has ensued in the media about the performance of these rapid antigen tests. No test is perfect in its performance – there are always false positives and false negatives and the goal is to minimise such results as we explain in the COVID-19 section of LTOAU. In the quest to deliver more rapid results there is a risk that speed will be achieved at the expense of test accuracy. More details about the performance of antigen tests and how they can be used appropriately is described in an article from the Doherty Institute in Melbourne who have been evaluating all COVID-19 testing methods.
It remains to be seen what role such antigen tests will play in the management of COVID-19 but it is clear that testing for COVID-19 will be required for some considerable time into the future and this will drive the need for further innovation to deliver more rapid and effective testing.
1. Beeching NJ et al. Covid-19: testing times. BMJ. 2020 Apr 8;369.
2. Price CP, St John A. Will COVID-19 be the coming of age for point-of-care testing? BMJ Innovations. 2020 Sep 8;bmjinnov-2020-000466.