Most of the NFL's COVID-19 surge this week has been driven by positive test results from asymptomatic players, an important data point as the league and NFL Players Association discuss ways to slow the spread through multiple teams.
More than 100 players have tested positive since Monday. Roughly two-thirds of them are asymptomatic, NFL chief medical officer Dr. Allen Sills told reporters Wednesday evening at the conclusion of a previously scheduled owners meeting. The rest, Sills said, have symptoms so mild that they might not have sought a test in ordinary circumstances.
Sills attributed part of this week's surge to the omicron variant, which he said has been detected in test results for multiple teams. In addition, Sills said, immunity among vaccinated players has likely waned, citing an antibody study of 572 NFL staff members the league recently completed.
"We have a lot of people in the NFL that have fairly low level of antibodies even though they are fully vaccinated," Sills said.
To begin addressing the issue of waning immunity, the NFL has mandated COVID-19 booster shots by Dec. 27 for all Tier 1 and Tier 2 employees, which include coaches and other football staff members. Players are not required to be vaccinated or boosted, but the league is ramping up efforts to encourage shots in the coming days and weeks.
According to current protocols, vaccinated players are tested once per week while unvaccinated players are tested daily. The NFLPA renewed its push Wednesday for all players to be tested daily, a request the NFL has rebuffed since the start of training camp. Sills said at the time that there had been no evidence of spread within team facilities this season, and that positive tests were all coming from the community, but he acknowledged Wednesday that was no longer the case.
Sills, however, said that daily surveillance testing has proved ineffective in other areas of public health. He noted there were multiple occasions last season when the league found evidence of a player spreading the virus even before he tested positive.
The sides are discussing other options, however. Among them is an adjustment for the return of vaccinated players who test positive. Current protocols allow them to return after two negative tests with 24 hours in between, but it's possible the sides could agree to allow them back sooner if they remain asymptomatic.
The NFL can make some adjustments on its own, including placing teams in enhanced protocols that require daily testing, mask wearing and virtual meetings. Sills said that five teams were under those measures as of Wednesday evening.
"We're doing what we've always done," Sills said. "We're evaluating what we're doing and looking at the effectiveness of our strategies and measuring it against our outcomes."
Despite the surge of positive tests, NFL commissioner Roger Goodell told reporters there has been no consideration given to postponing any games this week.