The White House apologised after Vice President Joe Biden stoked public alarm with a warning against use of planes and subways, as a quarter of US states reported swine flu infections.
The deadly H1N1 virus came to the heart of the US capital.
A member of the US delegation when President Barack Obama visited Mexico last month was believed to have been infected. His family is being tested, officials said.
A World Bank employee was also suspected to have had swine flu, and health officials confirmed 111 infections across 13 states.
But the Centers for Disease Control and Prevention (CDC) assured states that they would receive ample supplies of anti-viral drugs as officials vied to temper the intensifying public unease about the looming pandemic.
After Obama had said the disease was “a cause for deep concern, but not panic,” Homeland Security Secretary Janet Napolitano refuted the warning over public transport given by the gaffe-prone Biden. “It is safe.
The one caveat is that if you are sick… don\’t contaminate others by getting into a plane, a bus, a train, a confined space,” she said.
White House spokesman Robert Gibbs echoed a clarification issued by Biden\’s office, that the vice president had meant to stress a specific warning against non-essential travel to Mexico.
“I\’m apologising to those who were unduly alarmed,” he told reporters.
On NBC\’s “Today” show, Biden was asked whether he would advise his family members against flying to Mexico, the outbreak\’s epicenter.
“I would tell members of my family — and I have — I wouldn\’t go anywhere in confined places now,” he said. “It\’s not that it\’s going to Mexico — it\’s that you\’re in a confined aircraft.
When one person sneezes, it goes all the way through the aircraft,” Biden said.
He added: “I would not be at this point, if they had another way of transportation, suggesting they ride the subway.”
The Air Transport Association of America sent a letter to Biden to express its “extreme disappointment.”
“The fact is that the air on board a commercial aircraft is cleaner than that in most public buildings,” ATA president James May wrote, adding “we need to deal responsibly with the flu threat” while also keeping the economy moving.
US Travel Association president Roger Dow urged public officials to resist “inflammatory” remarks at a time of public fear.
“Elected officials must strike a delicate balance of accurately and adequately informing citizens of health concerns without unduly discouraging travel and other important economic activity,” he said.
Obama late Wednesday vowed to do “whatever it takes” to combat the flu outbreak, but insisted that closing the border with Mexico would do nothing to contain the disease and would carry a steep economic cost.
Biden told NBC: “Do we close the Canadian border too? Do we close flights coming out of countries in Europe where it has been identified now? “We\’re told that is not an efficacious use of our effort, that we should be focusing on mitigation.”
South Carolina and Nebraska became the latest of the nation\’s 50 states to confirm swine flu cases, a day after the CDC confirmed that the virus was to blame for the death this week of a Mexican toddler in Texas.
The child was the first person to die of swine flu outside of Mexico, and acting CDC director Richard Besser warned: “Unfortunately, I do expect that there will be more deaths.”
But Besser assured US states that they would receive enough drugs, with 11 million courses of treatment now being distributed from federal stockpiles.
“There are no reports, and we don\’t expect any reports, of shortages of any anti-virals in any states,” he told a news conference.