Now they say it will be more like 45 million. And with two doses needed to be effective, the nation's protection blanket will start out much smaller than the experts hoped, as CBS News medical correspondent Dr. Jennifer Ashton reports.
Just two weeks into a national testing program to see if the H1N1 vaccine is actually safe, comes word that there will be far fewer shots available in the fall, when a national vaccination program is scheduled to get started.
"We're in a race between vaccine and virus," said Dr. William Schaffner of Vanderbilt University Medical Center. "This gives the virus a bit more of an advantage. We'd like to start in as many people as soon as possible."
In July, it was projected that 120 million doses would be available by October, with another 80 million in the following months. Now, citing production delays, the government has been told by manufacturers that only 45 million doses will be ready by October 15, with approximately 20 million doses being delivered each week thereafter.
"The fact that we have fewer doses I think actually will focus attention," Schaffner said. "it will mean that we all will have to be much more specific about whom we will ask to show up."
The government says that it still expects to receive the same amount of vaccine as originally planned, just on a somewhat longer schedule. Experts say that now kids may jump to the front of the line.
Schaffner says that's both because children are more at risk to become sick from the virus - and because they're more likely to help spread it.
"Children excrete more virus. They are less hygienic. And they're very enthusiastic about kissing mom, dad, grandma, and aunt Susie," he said. "They are the great distributors."