By any definition, a moonshot is a spectacularly ambitious attempt to achieve a goal. So, when the UK government announced Operation Moonshot – to deliver the mass screening of 10 million samples for COVID-19 every day – we could all be forgiven a sharp intake of breath. It’s certainly fair to say that the prospect of developing new automated screening platforms to meet that figure by the target date of early 2021 sits somewhere between daunting and unlikely.
It might be viable, but will regulators accept remote human factors testing?
That said, I’m going to use this article to confront the challenge head on and unpack the possibilities of ramping up testing capacity to achieve the objective. At least in the short term, the most likely way will be by optimising the current infrastructure and replicating it across additional sites in the UK. As for details, I’ll explore some practical steps that will increase screening throughput by improving the efficiency of existing technologies while reviewing and removing workflow bottlenecks.
The pandemic has had a major impact on established clinical microbiology laboratories, as well as the new centralised facilities that were conceived and set up in response to the outbreak. In the preanalytical stage, collecting the respiratory tract specimen is essential for a prompt and accurate molecular diagnosis of COVID-19. Appropriate safety measures are needed to keep laboratory staff safe while producing reliable test results. The collection and receipt stage is very manual and labour intensive. Tubes are racked and samples are manually pipetted into deep 96 well plates.
In the analytic stage, real-time reverse transcription-PCR (RT-PCR) assays remain the molecular test of choice for the etiologic diagnosis of COVID-19 infection, while antibody-based techniques are being introduced as supplemental tools. The data flow is relatively simple, dealing with barcode tracking at well and plate level. Challenges will of course arise, from integration of the LIMs system. In the postanalytical stage, test results should be carefully interpreted using both molecular and serological findings. Managing the data and getting results to clinicians and patients rapidly is, of course, critical in order to isolate individuals and stem the spread of the virus.
Here are my five key areas of focus if we are to increase efficiency and capacity:
1. Identify and address bottlenecks
A joint expert team of biologists and engineers with automation expertise should map the entire laboratory workflow to identify bottlenecks and refinements. These would then be prioritised in order of impact so that changes could be implemented to achieve maximum efficiency.
2. Identify off-the-shelf automation solutions
Once the bottlenecks have been found, it would be preferable to address them with off-the-shelf components and solutions to increase throughput. Bespoke solutions would also be considered, if the extra functionality provided – or the reduced reliance on critical parts – was useful.
3. Sample and data flow
Sample and data flow are critical to the implementation of population-wide COVID-19 screening. Careful management of the sample flow is essential for a secure data flow and reliable reporting. This will include barcode tracking at well and plate level, with challenges likely to arise from the use of non-optimised LIM systems. A thorough review of existing systems should be undertaken to determine the most efficient, scalable and reliable approach.
4. Scalability of chemistry and tests
Alongside hardware and workflow, the availability and scalability of the diagnostic chemistry is critical. Storage and logistics are likely to be as important as physical availability. Identification of tests which are both scalable and practical will be essential.
5. Cost savings
It is of course essential to consider the costs associated with providing such a transformative screening capability. RT-PCR offers the best achievable sensitivity but is expensive. Screening at the hoped-for scale would cost millions of pounds every day. Miniaturisation through the reduction of the reaction volumes can often be achieved without any significant negative impact on the performance of the assay but is often limited by the accuracy of the liquid handling systems at lower volumes.
Thanks to our understanding of the science and sample handling requirements, the team at Cambridge Consultants is able to support the use of technology that drives miniaturisation and, in turn, significant savings. It is possible to conceive that much of this reduction in reagent usage, and subsequent cost reduction will be a very important consideration if this level of screening is required indefinitely.
Broad, holistic approach
So, my overall conclusion? There’s no doubt that rapidly identifying COVID-19 positive individuals across the UK will help control the virus until a vaccine arrives to boost immunity. But if we are to achieve such an ambitious screening target by early next year, it won’t be possible to design and build new customised systems. Instead, we must focus on ensuring that the existing infrastructure is operating optimally and scaled up as necessary.
I recommend a broad, holistic approach. It should balance scientific expertise with engineering and automation expertise. And it should involve a review of the existing infrastructure with very specific goals in mind. They are to increase overall speed, and so reduce the time between sample in and data out; to reduce the number of failed samples; to improve the accuracy of data, leading to more samples being screened; and to achieve miniaturisation that will lower the cost per test.
I’d be interested to know your thoughts, so please email me if you’d like to continue the debate. Meanwhile, look out for an article coming soon from my colleague Symon Cotton, who will explore the merits of the pooled testing approach.
