Anfang, who on Friday denied using a fake certificate, said he was resigning for the good of the club and the team. His assistant coach Florian Junge also stepped down.
"I decided to terminate my role as head coach at Werder with immediate effect given the burdensome situation for the club, the team, my family and me personally," Anfang said in a club statement.
Werder, playing in Germany's second division this season, had said on Friday an investigation was underway over the coach's vaccination certificate, with Anfang saying he had done nothing wrong and that he had been vaccinated twice at an official vaccination centre.
He said he had then digitised his vaccination certificate at a pharmacy.
"Markus and Florian show responsibility with this decision and contribute to ending the turmoil of the last days surrounding the team," said Werder managing director Frank Baumann.
"We respect this decision and will start the search for a new head coach."
The vaccination of players and team staff has been an issue for months in German football.
Bayern Munich midfielder Joshua Kimmich has triggered a heated public discussion as the most high-profile player to refuse inoculation and cited concerns over the long-term effects of the vaccine.
Abhishek Sharma's 19-ball fifty went in vain as world champions India were surprisingly beaten by Ireland for the first time in international cricket, slumping to a 34-run defeat in the first Twenty20 in Belfast on Friday.
England roared back into contention on the second day of the third and deciding test against New Zealand with Ben Duckett's rapid century helping his side to 223-2 after three wickets for returning captain Ben Stokes helped to dismiss the visitors for 438 at a sizzling Trent Bridge.
American great Serena Williams will face Australian 20-year-old Maya Joint in the first round of her eagerly awaited return to Wimbledon, a potentially tricky tie for the seven-time champion playing at the tournament for the first time since 2022.
Australia booked their spot in the knockout rounds of the World Cup on Thursday after a cagey draw against Paraguay, who are set to qualify as a third-placed finisher, while Turkey beat USA 3-2, scoring the winner with virtually the last kick of the match.
The UAE's National Emergency, Crisis and Disaster Management Authority (NCEMA) says a technical issue in the early warning system has been resolved after it led to the sending of incorrect alert messages.
His Highness Sheikh Abdullah bin Zayed Al Nahyan, UAE Deputy Prime Minister and Minister of Foreign Affairs, has held a phone call with Iran's Foreign Minister Abbas Araghchi to discuss the latest regional developments.