Their daughters Malia, 11, and Sasha, 8, got their shots in October when the vaccine first became available.
In an interview to American Urban Radio Network, Obama said the girls have been just fine and have yet to get sick this flu season.

"That's the most important population because this flu, unlike seasonal flu, disproportionately affects children and young people -- healthy children and young people as well as people with underlying conditions like asthma or neurological diseases," Obama said.

"I think people just need to understand:  If I had the two people that are most important in my life, my two daughters, get it right away -- and they've been just fine with it and in fact haven't gotten sick this entire flu season -- then you need to know that you need to make sure your children get it as well," he said.

The president also encouraged everyone to get vaccinated against the H1N1 strain of flu now that the vaccine is available to the general public. The vaccines had been restricted to high-risk groups such as children.