When children across the country put down their pens and pencils and filed out of classrooms on 5 January, we did not know when and how they would return. The UK was destined for a third national lockdown - meaning lost learning, and children being deprived of the kind of formative experiences you can only get when you pass through the school gates.
Three months on and more than 50 million tests later, the reopening of schools can be chalked up as a resounding success. The national reunion of children with their teachers and their classmates was no happy accident; it was one of the government's top priorities, and it's been the result of a huge collective endeavour.
Schools have been a shining example of how regular testing can help us find new cases quickly and stop the disease spreading further. It has shown what can be achieved when everyone involved - from the parents, pupils and teachers, to the maintenance and kitchen staff - are united behind a common goal: getting kids back into the classroom safely.
From the get-go, we recognised that we needed to do so as quickly as we could. Granted, thanks to the steely determination of our teachers, and the exceptional willingness of parents to take on teaching responsibilities and transform their homes into makeshift virtual schools, many children could continue to study. But there's no substitute for face-to-face learning.
To reopen safely, we knew that we had to rethink how we keep children and teachers safe at school. The science all pointed to the need for regular testing, which could serve as an early warning system, able to spot outbreaks, and arming local directors of public health with data, data, data.
And because around one-in-three people with COVID-19 show no symptoms -meaning cases going under the radar - we knew the centrepiece of this approach had to be rapid testing using lateral flow devices - or LFDs. Unlike PCR swab tests used for people with symptoms, lateral flow tests do not need to be sent to a laboratory, and are perfect to use on an everyday basis for people not showing any symptoms. They have proved a huge help not only in reopening schools, but in keeping them open.
For anyone reading this who is yet to use one, a lateral flow test is the testing equivalent of a Formula 1 pitstop - providing a lightning speed result in under half an hour. They're easy to use and effective at providing us all with a snap verdict on whether we could be unwittingly carrying the virus.
Like a vaccine, LFDs are at their most useful when used en masse. So, uptake in schools was always going to be vital - placing great responsibility in the hands of headteachers, teachers and learning assistants everywhere to encourage their students to make a test part of their routine.
But instead of viewing it as a burden, teachers in schools across the whole country enthusiastically rose to the challenge. I've heard powerful accounts of teachers sharing best practices with schools in their area, engaging with parents to stress the value of taking a regular test and building it into children's day-to-day schedules.
By making a COVID-19 test part of their everyday routine - as normal for some families as preparing a packed lunch or completing their homework - they've demonstrated how these tests can underpin the reopening of other things we all love.
Every positive test result is then backed up by a confirmatory PCR test which not only offers a second opinion, it screens the test result for variants of concern using the game-changing technology hosted in our sequencing laboratories. As this virus continues to evolve and attempts to bypass our defences, it is these capabilities that will help us outmanoeuvre the virus in the long term.
We've made it easier than ever to get one, with every single person in the country entitled to pick up two a week from their local pharmacy or have them delivered directly to their homes.
Today, children are heading back to school for the final half of the summer term and they'll be doing so safe in the knowledge that the only break in learning they'll be having is one where they head into the playground to kick a ball round and play games with their friends. Parents and guardians have been instrumental so far and, as they return to the classroom this morning, I'd urge every parent or guardian to test their children today.
50 million tests have got us here, here's to 50 million more. Let's not lose what's been achieved so far.
