Last week saw zero positive Covid-19 cases at any of the 72 English Football League clubs for the first time since twice-weekly testing began in January.
It comes a week after Championship side Rotherham recorded 25 cases following an outbreak among players and staff.
A total of 5,524 players and staff from all 72 clubs were tested between 15 and 21 March in the case-free week.
EFL chief executive Trevor Birch called it "a testament to the hard work and efforts of all clubs".
Since the EFL testing regime began with more than 100 positive cases recorded in the first week among the 66 clubs tested, they have mostly fallen week-on-week, bar the recent outbreak at Rotherham.
The Millers postponed three Championship fixtures while manager Paul Warne had to continue isolating when they returned to action against Watford earlier this month.
"Our focus must be on maintaining this low transmission rate and then ensure supporters can return in full as quickly as is safe to do so," Birch said.