The U.S. is facing another wave of COVID-19 infections as the holiday travel season begins. Cases are surging in more than a quarter of the country as the Delta variant continues to wreak havoc and cases of the Omicron variant tick up. Long COVID-19 testing lines are stretching around the block in cities like New York, Miami and Rockford, Maryland, as Americans of all ages rush to get tested before holiday gatherings. Along with packed airports comes fears of packed hospitals as the Omicron variant spreads at an alarming rate. The number of people traveling is approaching pre-pandemic levels with 109 million Americans expected to leave home for the holidays, a 34% jump from last year. More than 6 million of them will be flying. For those visiting New York City, it will be another Christmas without some of the city's famous events. On Friday, the Rockettes canceled the remainder of its Christmas Spectacular shows for the season, citing the rise in COVID-19 cases. Meanwhile, the sports world also continues to be impacted. The NFL has moved three games this weekend due to outbreaks, and the NHL is postponing all games for the Colorado Avalanche and Florida Panthers through at least next weekend. "This is not a moment to panic, because we know how to protect people. And we have the tools to do it," said Jeffrey Zients, the White House coronavirus response coordinator. The CDC said Omicron is expected to surpass Delta as the dominant variant in just weeks. It's now in at least 41 states. In New York City, hospitalizations are up 64% in just two weeks. "The rapid growth is frightening, and it evades antibodies induced by our vaccines," said Columbia University Medical Center's Dr. David Ho. Ho is advocating for boosters because being fully vaccinated with the Pfizer, Moderna and Johnson & Johnson vaccines is proving to be less effective against Omicron. "They all take a huge hit in terms of the antibodies that they induce against Omicron," Ho said. "The serum from J&J vaccinated individuals cannot neutralize Omicron." This comes as Pfizer announces that it is testing a third vaccine dose in children under 5 because two doses failed to give enough immunity to kids ages 2 to 4. And two new CDC studies are showing the effectiveness of the so-called "test to stay" strategy in schools. The studies found that kids exposed to COVID-19 can safely continue in-person learning if they are regularly tested at school. Meanwhile, there's concern over how some tests will hold up against Omicron. Dr. Anthony Fauci said some of the antigen tests may not detect the variant. And as Christmas approaches, doctors have this dire warning: "I think we need to be prepared for a surge in the coming few weeks. The wave that's coming will likely be the biggest."