DALLAS — Libby Caldwell thought it would be a good idea to get a flu shot before returning to the workforce.
"I'm going to be dealing with the public and out in the public more," she said. "I just felt it would be very important."
Caldwell never dreamed she'd be able to arm herself before summer was over.
Thousands of people waited for H1N1 vaccinations back in 2009. Because of that high demand, flu shots are available earlier than ever this year.
"Last year was early," said Walgreens pharmacist Julie Caldwell. "This year is even a month earlier than last year."
Caldwell says hundreds of Walgreens stores received vaccine supplies early as part of a CDC push to get Americans inoculated as soon as the serum is available.
Thousands of other pharmacies and physician offices across North Texas and the United States have also received vaccine.
Children are being specially targeted.
"They can just check this off on the calendar," Caldwell said. "At the same time they're buying school supplies, get a flu shot shot. Have everybody vaccinated before they're thrown back into school and being around a bunch of kids all the time where the risk goes up."
The CDC used to recommend October and November as the optimal time to get a flu shot. It was once thought that the protection would wane in 3 to 4 months.
According to the CDC, the immune response the body has to the vaccine actually lasts many months, making the best time to get vaccine sooner rather than later.
Libby Caldwell — and millions of others — are counting on that.
Scientists say age and overall health may determine how quickly immunity can fade. Protection generally lasts about a year.
Influenza virus mutates quickly, so vaccine must be updated and changed annually.
According to the CDC, the 2011-2012 flu vaccine provides protection against the three main viruses that research indicates will cause the most illness this season: Influenza A (H1N1) virus; an influenza A (H3N2) virus; and an influenza B virus.
It takes approximately two weeks after vaccination for antibodies that provide protection against influenza virus infection to develop in the body.
The Dallas County Health and Human Services Department is bracing for a very busy week — and possibly long lines. It estimates as many as 30,000 Dallas County students may still need to get their back-to-school immunizations before August 22.
About 300 people showed up for a clinic on Sunday. Students who don't get their shots could be sent home on the first day of school.
There are six dallas county clinics open from 8 to 4, Monday through Friday.