CENTENNIAL, Colo. -- People who want to get their seasonal flu shot right now may be out of luck, for now. Doctors across Colorado and the nation are running out or are out of the vaccine.

The problem is suppliers shifted their focus toward getting an H1N1 vaccine out quickly and in return have fallen behind in sending out new rounds of the seasonal vaccine.

John Sermini was one of the last few people to get the shot at his pediatrician's office in Centennial. Sermini's father said this year it was a priority.

"It's scary because we have H1N1 and then the regular flu. It's just really scary," said Sermini's father.

Advanced Pediatrics in Centennial is now waiting for another 4,000 vaccines it ordered to be shipped out. Dr. Mark Pearlman works at the office and said the delay comes at a bad time.

"This year it is because we've already seen some seasonal flu in the community different than H1N1," said Pearlman.

Those cases of the flu are several months ahead of when they normally pop up in January.

Denise Hall is the administrator at Advanced Pediatrics. She said huge demand has made the shortage an even greater problem. Doctors and other flu shot providers just can't keep up.

"Right now, what we're really sorry about is that we're having to call people and cancel their appointments that they made months ago," said Hall.

Some suppliers say the new round of seasonal flu vaccines could be shipped out as early November. For those who still hope to get the shot right now, they are urged to call around to different stores and doctor offices to see if shots are still available.