Covid: Meet Wales' virus variant hunters

By Owain Clarke
BBC Wales health correspondent

Published
media captionCovid: Who are the scientists hunting variants down in Wales?

She has only been in her job for three months - but Jess Hey is already on the frontline in the battle between science and Covid-19.

She is part of a Public Health Wales team of scientists who are on the hunt for new variants of the virus

As an ex-zoology student, Ms Hey studied the diet of birds - a very different discipline, but one that taught her lab skills she now uses.

She takes samples selected at random from positive Covid tests across Wales.

Working in a lab at the University Hospital of Wales in Cardiff, Ms Hey is a member of the Pathogen Genomics Unit (PenGu), which looks for tiny differences between the samples in the virus' genetic code.

image captionEx-zoology student Jess Hey is among the scientists looking out for new variants of Covid-19

"We are taking the genetic material and break it down into smaller fragments then add identifying tags so you know which patient the samples come from," she says.

"Then further down the line very smart people with computers can identify what the sequence looks like.

"So this is reading the entire genome and it's how we're finding new variants and how the virus is changing.

"I think it's really exciting to be part of something that's so cutting edge - I feel really fortunate I can help out."

image captionThe Pathogen Genomics Unit played a leading role in tracking the Kent variant

As viruses copy themselves within cells, and go on to infect others, tiny errors can occur.

Most do not have much of an effect, but some can have a significant impact.

A Covid variant, first spotted in Kent in the autumn, spread quickly and is now the dominant form across Wales and much of the UK

And the PenGU team played a leading role in tracking it.

Prof Tom Connor, PenGU's bio-informatics lead, said: "Viruses change all the time - like making photocopies of an ordinary original document.

"I think what was surprising to a lot of people, including us, was the speed with which actually the B117 [Kent] variant spread."

The effect of that new variant in the UK was stark and in many places it has gone from low numbers to 90% of cases in a matter of weeks.

"That's very, very quick and so one of the things that that science has been having to do is to try and work out why that is," said Prof Connor.

"Clearly, the next step is to try and start working out at an even earlier stage - are there mutations that we're seeing in our genome sequencing that we need to be worried about and get ahead of and much earlier?"

Since the start of the pandemic, the team has been able to read and decipher the entire genetic code of almost 30,000 Covid samples.

image captionProf Tom Connor said the speed the Kent variant spread surprised everyone, including experts

As a result they've been able to sequence between 15 to 20% of all positive cases in Wales since Covid arrived, one of the highest rates of anywhere in the world.

In England, between five and 10% of positive cases are being sequenced but that is still significantly higher than in many other countries.

Hundreds of samples

As the virus continues to mutate and evolve, the PenGU team have to work quickly.

The sequencing machines they use look like computer printers but cost about £180,000.

They are expensive because can read the entire long genetic code - about 30,000 bases or letters - of hundreds of Covid samples in a day.

One of the biggest efforts now is to try to limit the spread of what is thought to be a more vaccine-resistant Covid variant which emerged in South Africa.

The team have found 13 cases in Wales so far - of which 11 were linked to international travel.

"No matter what happens, the virus is going to mutate, we are going to see new changes coming along but people in Wales should have confidence that we have this world-class capability," said Prof Connor.

The information generated by the team is also helping those working on vaccines to tweak jabs to be more effective against emerging and future variants.

According to Prof Connor that will be crucial in the ongoing effort to bring this once-in-a-century pandemic under control.

'Arms race'

"Like everyone, I'm pinning my hopes on the vaccines working and all the data so far shows that the vaccines provide robust protection against severe disease," he said.

"That's an incredible position for us to be in one year on from it first arriving on these shores - to be in a place where we're carrying out mass vaccinations to protect the people of Wales in the UK.

"Medicine versus pathogens is always an arms race.

"And that's what's been built in the last 12 months, in terms of our genome sequencing capacity and other research capacity. It gives medicine and public health the weapons that it needs to be able to fight this pathogen."

And in that fight, Ms Hey and her colleagues are playing a pivotal role.

"I get a lot of questions from my family - my grandmother asks me what do you do exactly?

"So you're working on this virus? By the way what is a genome?"