France continue their quest for a first Grand Slam in a decade this weekend despite concerns the coronavirus could wreck the closing rounds of the 2020 Six Nations.
Ireland's match against Italy in Dublin, scheduled for Saturday, has been postponed by the global COVID-19 outbreak.
But Saturday's fixture between England and Wales at Twickenham and Sunday's Scotland-France match at Murrayfield are both going ahead as planned.
No replacement date has yet been set for the Ireland-Italy match, with the Championship meant to conclude on March 14.
The Irish Rugby Football Union could lose an estimated €10 million in revenue if the Italy match does not take place.
And with the window for earning ranking points ahead of the draw for the 2023 World Cup in France closing in November, there is an added incentive to play postponed matches.
In 2001, due to the highly contagious livestock foot and mouth outbreak, Ireland had three matches rescheduled to September/October that year.
But leaders France, the only team left in this season's Six Nations that can complete a Grand Slam, won't want the momentum built up by their youthful side to be interrupted by a gap of several months.
France avenged their World Cup quarter-final loss to Wales with an impressive 27-23 win in Cardiff last time out, a significant victory given how often Les Bleus have been accused of being flaky away from home.
"We have not invented anything, we did simple things with a lot of heart," said France captain Charles Ollivon.
"Now what we dream of is winning at Murrayfield. We'll go step by step, but we want to go even further, I won't lie about that."
The last round saw Scotland manage their first win of this Six Nations with a 17-0 success away to Italy, but they will have to raise their game considerably if they are to derail France, who finish the Championship at home to Ireland.
Scotland remain without fly-half Finn Russell following the talented playmaker's falling out with coach Gregor Townsend.
But relations between the pair appear to be thawing with Russell, who plays for Paris-based Racing 92, telephoning Townsend with some 'inside information' on the French team.
"The fact that there has been some real good communication going on bodes really well for the future," said Scotland assistant coach Danny Wilson.
World Cup finalists England could yet win the title if France, who beat them in their Championship opener, slip up against either Scotland or Ireland.
England coach Eddie Jones was in bullish mood after a 24-12 win over Ireland.
"We know every time England play Wales it's the biggest game there's ever been," he said. "We will be better against Wales."
England withdrew Mako Vunipola as a precaution after he flew back from Tonga via Hong Kong but the prop's club, Saracens, said he had not displayed any signs of the new coronavirus and would be available to play against Leicester this weekend.
Loosehead prop, however, is an area of English strength with both Joe Marler and Ellis Genge available to Jones.
Reigning Grand Slam champions Wales, under new coach Wayne Pivac, travel to Twickenham looking to avoid suffering three successive Six Nations defeats for the first time since 2007.
Influential flyhalf Dan Biggar is doubtful with a knee injury while wing George North is continuing his recovery from a blow to the head.
Wales have not won at Twickenham since 2012 when Sam Warburton, now a member of Pivac's backroom staff, was their captain.
"You learn it the hard way, it's a tough place to go," Warburton said.
"I only had two wins in my whole career there."