Between 35,000 and 40,000 Americans die from the seasonal flu every year and that's when 30 to 40 percent of the population gets immunized.
That's why the new /*H1N1*/ vaccine is so important, the most important prevention tool there is.
Federal health officials say they're expecting at least 100 million doses of H1N1 flu vaccine to be ready by this fall. Two billion people, or one-third of the world's population are expected to be infected with H1N1.
"The best way to prevent the spread of flu is vaccination. A seasonal flu vaccine is ready to go, and we should have one for the 2009 H1N1 flu by mid-October," said Health and Human Services Secretary Kathleen Sebelius.
"What this means for us in San Francisco is that we should receive about 200,000 doses with the first shipment which is a very large amount of vaccine," said Dr. Susan Fernyak from the San Francisco Department of Public Health.
The San Francisco Department of Public Health says people will need to get three shots -- one regular seasonal flu vaccine and two doses of H1N1 vaccine, about three weeks apart.
Small children who've never had a seasonal flu shot will need two of those, and two of the H1N1 for a total of four.
"So those parents are going to have a few logistical issues getting their kids in to get all of those doses," said Dr. Fernyak.
Unlike earlier this year, federal officials are not telling schools to close if students get H1N1, but they are saying infected students and staff should stay home for 24 hours after the fever breaks.
The Health Department is considering giving the vaccine in schools, but hasn't started talking to the district yet about feasibility.
The district says it will do whatever health officials think best.
When his pneumonia didn't respond to medication in June, 17-year-old Charlie Wilson went to the hospital and was tested for H1N1 FLU, turns out he just had an unusual case of pneumonia.
If the H1N1 vaccine isn't offered at his San Francisco high school this fall, he might get it from his doctor.
"I might just get it if it's causing problems around here and just to be safe," said Wilson.
We need two doses of the H1N1 as opposed to just one of the seasonal flu because H1N1 is new, and we have no underlying immunity as we have with seasonal flu.