A Korean Air flight headed to Las Vegas from Seoul, South Korea, was diverted Wednesday to LAX over concerns that some of the passengers might have been exposed to a new virus, the airline said. Three passengers, all US passport holders, were allowed back on the flight after showing no symptoms during a screening at LAX, the airline said. The plane continued on to McCarran International Airport in Las Vegas with all original passengers on board, the statement said. The flight was diverted after it was determined that the three passengers had been in China within 14 days of their departure from Incheon International Airport in Seoul. A spokesman for McCarran airport confirmed that there were “concerns that passengers aboard had been to China.”<br/>