The National Football League is urging teams to make Covid-19 vaccines "easily and conveniently" available to players, and offering modified virus protocols for those vaccinated.
In a memo to teams on Friday, obtained by the NFL Network and other US media, the league said it had agreed with the NFL Players Association on modified Covid-19 protocols for vaccinated players, who wold have to be tested on a weekly rather than a daily basis.
They would also no longer have to quarantine if judged to have had "high risk contact" with someone who tested positive, and would not have to submit to "entry" testing in the wake of travel.
The league said the modified protocols were arrived at with advice from medical and scientific experts about the reduced risk of fully vaccinated individuals becoming infected.
"All clubs should continue their efforts to educate about available vaccines to maximize vaccine acceptance among their staffs, players, and family members," the memo says.
"Each club should make the vaccine easily and conveniently available through a 'Vaccination Day' or other program, and we will continue to work with the joint NFL-NFLPA committee to develop additional educational material that communicates the benefits of the vaccine to players, staff and families. All clubs are participating in this effort."
Some precautions such as mask-wearing and the use of tracking devices in team facilities to facilitate contact tracing will still be required of vaccinated individuals.