Tobias Wauer – a report from the COVID-19 testing front line

It’s 8pm and I’m about to start a 12-hour shift at the national COVID-19 testing centre in Milton Keynes. Truckloads of boxes with transparent plastic bags just arrived and a brief announcement is made: 15,000 patient swabs. For now, the mood among the team is cheerful and enthusiastic, but I know it will have morphed into exhaustion and fatigue by the end of the night.

Rewind: In March 2020 I was on course to take up a new research role at Harvard. On the very same day I returned to Cambridge from a meeting with my future collaborators in Boston, Trump announced the travel ban to Europe. Shortly after, entire countries went into lock-down, laboratories all over the world closed their doors and my research collaboration was deferred to an unknown date in the future. Facing indeterminate months confined to my sofa, I signed up to a call for scientist volunteers that was circulated by the University of Cambridge. The requirements weren’t very specific, and after almost losing hope that I would ever hear back, I received a phone call inviting me to assist in the ramp-up of the UK’s testing capacity. This came to some surprise. I have worked on the molecular causes of Parkinson’s and cancer, but I would have thought viral diagnostics was certainly beyond my expertise. In any case, I was delighted to find new purpose and three days later, I arrived with a handful of other volunteers at an industrial estate near Milton Keynes that was home to the UK Biobank. On the outside it resembled a warehouse more than a lab, but an impressive management team including many of the UK leading scientists had already been assembled. The team leader, who had just arrived the week before, introduced us to the task at hand of creating a facility that would be the backbone of the UK’s testing strategy – how this goal would be met however, seemed to be far from clear. At this point, the main lab to process the tests had not even been constructed and unboxed equipment was piling up. There was no indication this would soon become the largest coronavirus testing site in the UK.

Most of the new recruits have PhDs and spent years in scientific research, but we initially shared a common anxiety that few of us have had much experience dealing with coronaviruses. My own expertise seemed a far cry from viral diagnostics. As it turns out there was little cause for concern: the coronavirus test is actually quite straightforward. At its heart lies the Polymerase Chain Reaction (PCR), arguably one of the most widely-used methods in molecular biology and a procedure undergraduates students learn as part of basic laboratory training. In a PCR test, the genetic material of the virus is mixed with enzymes that can build and replicate DNA. Short DNA sequences called “primers” are then added to the reaction. In a positive test the primers ‘recognise’ viral genes by initiating their replication. Hence, when gene amplification is observed, viral genes must be present and the PCR test returns a positive result. All of the newly arriving scientists had used the PCR technique in their own research many times before and it quickly became apparent that coordination and good management was a greater challenge than technical knowledge of coronavirus biology if this unprecedented undertaking was to succeed.

From the start, one of the biggest challenges was in gathering equipment. Seemingly difficult tasks turned out to be straightforward, whilst trivial ones became surprisingly intractable. Expensive machines donated from institutes all around the UK were installed within a couple of days. Manufacturers massively ramped up production of sophisticated test reagents and we were able to build up our stocks. However, things as seemingly trivial as a shortage of certain pipettes threatened to stall the whole operation for days as thousands of tests waited to be processed. In an emergency like this it was handy to have a direct line to institute heads around the UK who were eager to help. One more call and an army truck with dozens of pipettes and other equipment arrived three hours later. The collaboration between permanent staff, scientists, external institutes, private companies and the armed forces made it possible to set up a working lab within a matter of days. Every week dozens of new volunteers were recruited from top universities and institutes all over the UK. They received a week of intensive training and by the following week were themselves training the next intake of volunteers under the supervision of a shift leader. Within two weeks the site changed beyond recognition. New labs had been fitted, robots have been installed, dozens of new hires were being trained every week and my initial skepticism started to dissipate: we could actually do this!

With essential equipment installed, it was time to scale up. To an experienced scientist performing a single PCR test is straightforward, but running 10,000s of tests a day is a different story. Time and again simple considerations turned out to be the most vital: “What’s the best way to extract the sample from its packaging?”, “Should the barcode be scanned before or after the sample is taken out?”, “On which side of the lab bench should the pipette lie?” “At what moment should the pipette be mounted with a pipette tip?”.  Feeding a robot with samples turned into a pit stop with Formula 1-like efficiency. One operator takes out the old samples, a second replenishes test reagents and a third loads another 94 samples. 10 seconds, done. Soon we had an integrated workflow of dozens of steps running like a perfectly orchestrated clockwork.

While speed was important, precision was vital. A false negative result could see a nurse or resident going back into a care home to infect dozens of vulnerable patients, a false positive might see a healthy doctor sent home from ICU to self-isolate for a fortnight, or a key worker sending half their company into quarantine. To prevent this, a sample had to be tracked electronically and on paper at every stage. Every intervention by a scientist had to be supervised by another to help prevent human error. As our team grew, strict training routines needed to be established with clear rules. How do you write a “1”, an “I” and a “7”? Is it a “5” or an “S”? How do you distinguish an “O” from a “0”? Lecturing experienced professionals about how to write numbers and letters made me feel absurdly pedantic, but to minimise all possible sources of errors it became clear that common rules had to be followed religiously. Every change to protocol, no matter how large or small, needed to be cross-validated with known test samples and approved by a testing specialist.

After four weeks, the continuous flow of recruits allowed to move towards 12-hour shifts, eventually 8am - 8pm and 8pm - 8am, 24/7. I lost track of the time-of-day and the days of the week. Weekends and Bank Holidays became indistinguishable from the working. The daily routine was subject to the mantra: ‘Test. Test. Test’ to quote Tedros Adhanom, the head of the WHO.

In the first week the manual sample handling process allowed a throughput of a couple of hundred samples, with more volunteers coming in this increased to a couple of thousand, and with the help of robots quickly reached tens of thousands of processed tests per day. Just like the spread of the virus we were competing against, it was an example of exponential growth. What would normally have taken months or years to establish, now took days or weeks.

The progress on testing has received a lot of bad press and many of us at the test centre felt they were being made personally responsible for hitting government targets. This added pressure caused frustration, especially when everyone gave their very best to make this undertaking a success. It needs to be put into perspective from where the project started and what has been achieved: Within weeks, the joint efforts of hundreds of volunteers has enabled our lab to process more than 30,000 tests a day – or less than 3 seconds per test!

After a couple of weeks, this put us in a position where the processing of the COVID-19 tests was not the limiting factor of the testing initiative anymore and soon there had been hardly a day where our testing capacities were used to the full. Therefore, the debate should be less about the available testing capacity and more on how to make best use of what is available.

If there is one positive take-away, it is that despite the challenges and the country’s seeming divisions it remains possible for us to rally around a common goal. Volunteers joined the testing initiative from all corners of the country, many of them internationals from Europe and beyond living and working in the UK, eager to help in the common effort to fend off the invisible enemy. The spirit of creating something unprecedented was in the air and one part of the key to win this fight lay in their hands. The work of these people has saved lives and it was my great privilege to have been part of this collaboration.

In some way I see Emmanuel in a similar tradition; a place where students and academics can thrive irrespective of their backgrounds and create something that is more than the sum of its parts. Emma gave me the unique opportunity to be part of this community as a Research Fellow and beyond, and without its support I would have not been part of the UK’s testing initiative. As such, I am grateful for Emma’s support, as well as that of the Wellcome Trust and the Medical Research Council.

Dr Wauer is a former Emmanuel Research Fellow and a current Bye-Fellow of the College. He is also a Sir Henry Wellcome Fellow at the MRC Laboratory of Molecular Biology. 

A version of this article was published on The Conversation and The Independent.