The New Orleans Saints have officially made it clear that unvaccinated individuals will not be allowed to attend games this season. The hope is that if only vaccinated fans can attend, more people will take it upon themselves to take the shot so that they can attend an NFL game. The other option is to take a COVID-19 test before each game, which is more cumbersome and expensive.The New Orleans Saints are requiring everyone entering the Superdome to show either proof of vaccination or a negative #COVID19 test. The @Saints will not issue refunds to any ticket holders who refuse both the vaccine and the COVID-19 test 👀 pic.twitter.com/ConCG1gQDH— Sportskeeda Pro Football (@SKProFootball) August 18, 2021Before the New Orleans Saints, the Las Vegas Raiders became the first team to require proof of vaccination for all attending fans.BREAKING: #Raiders become first NFL team to announce a vaccine/no mask policy.All fans @AllegiantStadm are now required to be vaccinated, allowing fans to attend games without a mask.Fans can receive vaccinations at the stadium prior to home games #RaiderNation @FOX5Vegas— Vince Sapienza (@VinceSapienza) August 17, 2021Is this the beginning of a domino effect where other teams follow suit? Or is this an aberration? The truth is somewhere in between.NFL's stance on vaccinationThe NFL has been pretty firm in its support for vaccination, something that has caused friction among players as some remain staunchly against vaccination. However, due to the steep fines and the possibility that their team may forfeit points if there is a COVID-19 infection in the squad due to an unvaccinated player, many players have taken the vaccine despite their dismay.While the NFL has been able to mold players' actions with their policies, they cannot influence fan behavior. That lies outside their remit. Hence, the NFL cannot ask fans to show vaccination certificates.Local policy to increase vaccinated populationThe authority to determine whether fans attending in a stadium should be vaccinated falls squarely on local representatives.For example, in the case of the Las Vegas Raiders, the directive for only vaccinated people being allowed to enter followed a new Emergency Order by Governor Sisolak of Nevada. In fact, to make the process easier, their home stadium itself will double up as a vaccination site.Similarly, the decision taken by the New Orleans Saints in favor of vaccinated fans followed a directive by New Orleans Mayor LaToya Cantrell, who mandated that all events held in 2021 in the Superdome can only be attended by vaccinated persons.Whether NFL stadiums will require their fans to be vaccinated does not depend on the NFL; it's based on local laws. Such laws may pertain to the city or the state. As the regular season rolls in, the highest likelihood is that of a mix of stadiums that mandate vaccines and others that do not.