NFL COVID-19 protocol changes, Week 15 postponed games, new testing and return-to-play rules: Can the NFL navigate the omicron variant?

In many ways, the NFL entered its third COVID-19 pandemic last week. The first hit during the 2020 season, as the league maneuvered through a 17-week schedule without the benefit of vaccines. The second took place during Weeks 1 through 14 of the 2021 regular season, a battle against the delta variant using protocols designed to incentivize vaccination. And now, NFL chief medical officer Dr. Allen Sills said over the weekend, the league and the NFL Players Association are "in some ways battling a brand-new disease."

The omicron variant hit the league at the end of Week 14, powered an unprecedented surge of more than 150 positive cases in Week 15 and prompted the first three schedule changes of the season. The second and third of those games will be played Tuesday night, after which the league and union hope the remainder of the season can be played on schedule. Early analysis of the omicron variant's impact on the league, which included significant transmission among vaccinated players but little to no symptoms for most, led to an overhaul of protocols that govern testing and return to play.

Will the changes work? Did the NFL prioritize games over the health of players, coaches and the surrounding community? Let's take a closer look.

What were the circumstances that led to all of this?

The NFL entered the season with vaccination rates of 94% for players and nearly 100% for football staff members. Vaccinated individuals were tested once per week, and those who remained unvaccinated were tested daily. Through the first three months of the season, in six testing periods that spanned Sept. 5 to Nov. 27, 110 players and 187 staff members tested positive.

Toward the end of Week 14, the league identified several positive cases caused by the omicron variant. Vaccinated players were scheduled for weekly testing on Mondays under the previous protocols, and the Dec. 13 results were stunning. A total of 37 players returned positive tests that day, and the pace continued. By week's end, more players had tested positive than in the previous 14 weeks combined, just as several major cities, including New York, were reporting similar surges. Since Dec. 13, approximately 200 players leaguewide have tested positive for COVID-19, and as of Monday evening, north of 150 were on the COVID-19/reserve list.

And that's all because of the omicron variant?

Predominantly but not exclusively, according to the league. Preliminary data from genomic sequence tests suggest that last week's surge was "overwhelmingly" omicron, Sills said.

But waning vaccine immunity and seasonality also played a role. The NFL recently conducted a voluntary antibody study of 527 staff members and found clear signs of waning immunity among those who had not received a booster shot. The league has since mandated that all Tier 1 and Tier 2 employees -- which includes coaches and other football staff members -- receive boosters by Dec. 27. Players have been encouraged to get vaccinated and boostered, but they are not required to do so, per the league's agreement with the NFLPA.

What else is the NFL doing about this surge among players?

Put simply, it has joined with the NFLPA to reduce testing of vaccinated individuals and shorten the return-to-play process for those who have tested positive.

How does that make sense with such high infection rates?

It's a fair question. Let's take the changes one at a time.

OK then. What about testing?

From the top, it's important to remember that the NFL, the NFLPA and the larger public health community are trying to evaluate omicron in real time amid a surge of unprecedented speed. No one can say with absolute certainty what strategy will work best. These are all educated guesses.

With that said, the NFL and NFLPA decided to halt weekly testing of vaccinated players and coaches and implement a random cadence that is not dissimilar to its drug testing. The new protocol does not specify how many such individuals will be tested per week, but it will include "a sample selection based on position group and staff cohorts," as decided by the league's health and safety office.

In addition, if a vaccinated player or staff member reports symptoms, he or she will be required to be tested.

Wouldn't that approach miss a lot of positive cases?

Simple math tells us that, yes, there will be more unidentified asymptomatic cases in NFL buildings for as long as the omicron surge lasts. But the nature of omicron cases to date should also be taken into account. According to Sills, more than two-thirds of the total positive cases in Week 15 were asymptomatic. Most of the remaining cases featured mild symptoms.

In one anecdotal example, Dr. Tony Casolaro, the chief medical officer of the Washington Football Team, said that only two of the 23 players who tested positive last week had symptoms significant enough to miss practice if it were a non-COVID-19 illness.

The desired outcome here is obvious: Fewer tests in theory will lead to fewer sidelined players. The question is whether those with unidentified asymptomatic cases would still be contagious. Since March 2020, of course, much of the public health response to COVID-19 has revolved around the dangers of asymptomatic or presymptomatic spread.

The NFL did not respond to questions posed Monday about that possibility. Zachary Binney, an epidemiologist and an assistant professor of quantitative theory and methods at Oxford College of Emory University, said that mild or no symptoms generally "correlate with lower viral load, which should in turn correlate with lower transmission risk -- but not zero risk."

Sills said the NFL and NFLPA are "trying to test smarter and test in a more strategic fashion." He added: "We've always said that we don't really want to put people on the field or in the locker rooms or anywhere when we think that they have substantial risk of passing the virus on to others. We don't want to see people become infected. Full stop."

How will the NFL know if vaccinated players are suffering from symptoms?

They are required to self-report. "We are emphasizing personal responsibility," Sills said. "We are asking every person, player, coach or staff member to be honest and to report their symptoms."

How will it be quicker for sidelined players to test out of protocols?

To this point, vaccinated players and coaches could return once they tested negative twice with at least 24 hours in between, as long as they had no symptoms. Unvaccinated players who tested positive were required to sit out 10 days. In most cases, this was a distinction without a difference. Only about 20% of vaccinated players who tested positive were able to return in less than 10 days.