Covid: Sports events to go ahead behind closed doors - but what's the science behind it?

• Video report by ITV Wales Correspondent Richard Morgan

The festive season is upon us and there's usually a buffet of sport to watch in stadiums and arenas across the country.

But this year events will be held behind closed doors as the Welsh government continues its fight against Covid-19's Omicron variant.

So why have these rules been put in place, and why are sporting events being restricted before other venues?

"We know the virus spreads from person to person when they're crowded together," says Dr Andrew Freedman, who specialises in infectious diseases at Cardiff University.

He said: "Outside, as opposed to inside, is less risky but I think if you've got loads of people entering a crowded stadium and mixing or if you're sitting down and shouting, they will increase the risk of transmission."

"We don't understand absolutely why Omicron is more transmissible than the Delta variant but we do know the mutations in the spike region of the virus, that's the outer coat of the virus. The spike binds to human cells which are necessary for infections to occur. We know that those mutations mean that the binding is that much stronger and that probably accounts for the increased transmission rates."

"There's a degree of uncertainty of what hospitals are going to see which is one of the major considerations given that the NHS is already at full stretch. There isn't much slack in the system - especially if staff numbers are low."

The latest figures show Omicron cases are rising quickly in all parts of Wales. 

The overall rate of coronavirus infections is also rising in Wales and now stands at just under 550 cases per 100,000 people.

Economy Minister Vaughan Gething said: “Sporting events over the Christmas period are one of the big highlights of the year. Unfortunately, the new Omicron variant is a significant development in the pandemic and could cause a large number of infections.

“We need to do everything we can to protect people’s health and control the spread of this awful virus.

“Throughout the pandemic, we have followed scientific and public health advice to keep people safe. The advice is clear – we need to act now in response to the threat of Omicron. We are giving people as much notice of these decisions as we can.

“Crowds will come back as soon as possible. We want everyone to be here to enjoy their favourite sports.”

Cardiff City chief executive Mehmet Dalman has described all sports fixtures moving behind closed doors in Wales as a “major blow”.

CEO Dalman insisted all new guidelines will be followed, but conceded another shut-out of fans will hit the Bluebirds hard.

“It’s a major blow from all aspects, but we have to put the safety of our fans, players and everyone first,” Dalman told talkSPORT.

“So we will follow the guidelines as they are laid out.

“These things are made for a reason and as much as we dislike them, we will certainly obey them.

“It’s a blow of course for football, a blow for our club, because we always want to play in front of our fan base, and that’s a great shame.”

In England, sporting events are still governed by the Plan B rules that came into effect on December 15.

Fans of Welsh football clubs should currently still be able to attend away matches in England, but Dalman feels further restrictions may be in the offing.

Asked if Cardiff fans could travel to away matches in England, Dalman replied: “Theoretically speaking that’s correct, in practical terms, let’s see what happens next.

“There are a lot more developments to come, I’m sure of that.

“So I would just wait to see the next announcements from the government as to the guidelines, and we go from there.”

Cardiff against Scarlets in the United Rugby Championship (URC) on Boxing Day will be the first major fixture affected.

Cardiff Rugby say they "explored alternative options, including the postponement of the fixture until crowds were permitted" but added, "permission from URC was not granted".

Director of rugby Dai Young said: "We all understand that health and wellbeing are paramount."

"We have to be honest how disappointing playing in front of no crowds is. Especially over the festive period. A local derby doesn't happen every week. It's really disappointing to lose a fantastic opportunity to play in front of a full house."

He added: "At the end of the day we are a business, if we keep on having setbacks - it's going to have a commercial impact. As rugby players and rugby staff, we're fully aware that that pays our wages so we're fully aware that's going to put the club under pressure."

Ospreys against Dragons on Boxing Day has already been called off because of positive Covid tests, as have football matches that day for Cardiff City and Newport County.

Wrexham are set to entertain Solihull Moors in the National League on 26 December, and while Swansea City are away on Boxing Day they then have home games with Luton (29 December) and Fulham (3 January).

"I may not be thanked for being frank, but this is horrendous news for us. This is brutal news," Dragons chairman David Buttress said on social media.

"[It is] devastating for professional rugby and sport".

Scarletts Executive Chairman Simon Muderack said that while spectator safety is paramount, the financial impact will be felt across Welsh sport.

The Welsh Grand National at Chepstow on 27 December will also be held without spectators.

Executive Director of Chepstow Racecourse, Phil Bell, said: “The Welsh Grand National is one of the biggest and most popular events over the Christmas period in Wales, so we are obviously hugely disappointed that we will not be able to welcome back racing fans this year."

The rules will apply to all levels of sport in Wales, including semi-professional and grassroots.

John Dunleavy, head coach of Dinas Powys RFC says they've lost 20 players since lockdowns began. 

"There's a lot of teams, especially at second-team level, struggling to field teams. A lot of players haven't returned to playing since the last lockdown, and I think if we go back into that same situation it could encourage more players to do the same"

While some say the new rules could simply drive the virus indoors. 

Leader of the Welsh Conservatives, Andrew RT Davies said: "I understand that this is a fast-moving situation but as the restrictions stand at the moment you'd be able to go into a pub and watch Sky Sports in a big group but you wouldn't be able to go to your local football or rugby ground to watch your favourite team. So there's an inconsistency there."