An unnamed Scotland Women player has contracted the coronavirus following the team's visit to northern Italy.
Grand Slam hopefuls France have made two changes for their match with Scotland, who have Fraser Brown poised to win his 50th cap.
England overlook Mako Vunipola as a coronavirus precaution, yet he will play for Saracens against Leicester Tigers.
England are expecting a tough battle against Wales and Eddie Jones believes last year's loss in Cardiff provides perfect motivation.
Wollongong set the stage for back-to-back Super Rugby clashes on Friday, with the Brumbies and the Chiefs enjoying victories.
Wales boss Wayne Pivac expects a "big performance" against England after stepping up intensity in training, epitomised by Alun Wyn Jones.
France head to Murrayfield scenting a Grand Slam and a first Six Nations title in a decade, while wounded Wales face England.
Wales have lost back-to-back Six Nations clashes and will face England at Twickenham on Saturday with a side showing four changes.
Italy have had a second Six Nations match postponed due to the coronavirus, with doubts over whether the tournament will be completed.
Mark Wilson and Anthony Watson replace Sam Underhill and Jonathan Joseph respectively in the England side to face Wales.
Following a decree by Italy's prime minister, England's final Six Nations match of 2020 looks set to be played without fans in attendance.
Consistency of performance is what England have been lacking in the Six Nations, according to World Cup-winning captain Martin Johnson.
Mako Vunipola could play for Saracens this weekend, but England were advised not to take any risks following the prop's trip overseas.
Chris Ashton has returned to London to join Harlequins after his Sale Sharks contract was terminated.
Saracens have clarified Mako Vunipola has not been in self-isolation and is free to play Leicester Tigers this weekend.
Experienced duo Dan Biggar and Liam Williams are on course to be fit for Wales' showdown with England at Twickenham.