Just as the pandemic seems to be waning across the country, some health officials are worried that Thanksgiving holiday gatherings could lead to more infections. So the government has launched a new travel-health campaign. "It"s important to remember the things that everybody can do to stay healthy," said Dr. Beth Bell of the Centers for Disease Control and Prevention. Thanksgiving is typically followed by at least a modest bump in early seasonal flu cases, according to reports from the past few years. But this, of course, is not a typical year. Swine flu is a new virus that accounts for nearly all flu cases right now. Despite weeks of declining infections, health officials are staying vigilant. The federal government is putting up posters in airports, seaports and border crossings in time for Thanksgiving. The campaign includes advertisements with slogans such as "Stop, Wash & Go." The CDC urges people to travel only if they are well, get vaccinated against swine and seasonal flu, wash their hands often, and cover coughs and sneezes with a tissue or sleeve. About 33 million Americans are expected to take to the nation"s highways over the Thanksgiving holiday, a slight increase from last year. About 2.3 million more will travel by airplane. Swine flu has sickened an estimated 22 million Americans, hospitalized about 98,000 and killed 4,000 since it was first identified last April. It is similar to seasonal flu but poses a much bigger threat to children and young adults.