ALEX DOMINGUEZ Associated Press Writer BALTIMORE (AP) — With a swine flu outbreak spreading across the nation, more than half the states have yet to stockpile the number of flu-treatment doses recommended by the federal government, an Associated Press survey found. States that are falling short cite budget constraints, or say it's better to spend health-care funds on preventing the spread of disease than on antiviral medicines that may or may not work on a particular flu strain. "You don't have any guarantee that if you purchase a large amount of drugs that they would be effective in the future," said Gwenda Bond, a spokeswoman for the Kentucky Cabinet for Health and Family Services. "Drugs do have a shelf life, and so you don't want to spend a lot of money on drugs that may expire before you need them." The strain of swine flu that began appearing in Mexico and has since spread to 11 U.S. states is treatable — but not preventable — using Tamiflu and Relenza, each of which has a shelf life of about five years. However, the drugs' effectiveness is limited. Tamiflu, the more commonly stocked of the drugs, needs to be taken within in first 48 hours of the onset of symptoms, according to its manufacturer, The Roche Group. It generally only reduces the duration of symptoms. Still, the U.S. Department of Health and Human Services recommends that each state have enough antiviral medicine on hand to treat 25 percent of its population. But an AP survey of all 50 states and the District of Columbia found that 29 were below that threshold. Several were just under it, but 15 states had enough medicine on hand to treat fewer than 20 percent of residents. Seven states — Arizona, Colorado, Connecticut, Florida, Idaho, Massachusetts and Montana — could treat about 15 percent. Despite that, the acting head of the U.S. Centers for Disease Control and Prevention said no state is expected to experience shortages because the federal government is racing to fill states' stockpiles with millions of additional doses from its own strategic reserves. Dr. Richard Besser said Thursday that the CDC had deployed drugs to nine states so far, and that all 50 states would receive allocations from the national reserve by Sunday. Besser said the deployment is being done "as a forward-leaning move ... in case this becomes something much bigger than it currently is." Federal officials also said that there was no shortage of the medicine in regular pharmacies. A course of antiviral medicine contains enough doses to treat one person. In 2006, as part of its own pandemic flu preparations, the federal government created a stockpile of 44 million courses, which would cover about 15 percent of the U.S. population. It then recommended that states purchase additional courses so the combined stockpiles would cover one quarter of each state's population, and offered subsidies covering 25 percent of the cost. Because some states passed on the subsidies, other states were able to use the federal aid to go beyond 25 percent coverage. Hawaii has enough for nearly 29 percent of its population. It bought more than the recommended amount because of the year-round stream of tourists who boost its population. Bill Hall, a spokesman for the Department of Health and Human Services, said the federal government based the 25 percent figure on past pandemic outbreaks in which about a quarter of the population became infected and "made it clear this is shared responsibility with the states." The swine flu outbreak is a road test of sorts for battling an outbreak with antiviral medicine, said Trish Perl, an infectious disease expert at the Johns Hopkins University School of Public Health. "None of us have ever really done this practically," she said. "Right now is the first time that we've been able to really test it with some of the prevention strategies that have been used in states where they have had some of these cases. So, I think the good news is that we're going to know relatively soon." Georgia Gov. Sonny Perdue had originally proposed spending $15.7 million for about 2.2 million courses in 2007, but the spending was cut to $7 million by state lawmakers and the state ended up purchasing 460,000 courses instead. Combined with the 1.3 million currently allocated by the federal government to Georgia, that's enough to cover about 18 percent of the state's population of 9.7 million. Kentucky health officials' decision to get half the amount recommended under the federal guidelines came down to both a policy and financial decision, Bond said. Health officials did not want to buy too much medication that may not be able to treat a pandemic or could eventually expire and go to waste. "But at the same time, we did feel that it was prudent to ... have some on hand, because they are effective against many flu strains," she said. So Kentucky spent about $3.6 million on antiviral courses, which is "no small expense" for a state that's facing massive budget woes, Bond said. Kentucky has enough to cover just over 20 percent of its population. Colorado and Maine are among the states that chose not to stockpile treatments, deciding the money would be better spent on hygiene education, canceling large gatherings and other precautions against a pandemic flu. "Since this is the biggest gain for the dollar, this is where we have put our efforts," said Chris Lindley, division director for the Colorado Department of Public Health and Environment. In Massachusetts, where the state has enough antivirals to treat slightly more than 15 percent of the population, health department spokeswoman Jennifer Manley said the state's decision not to buy the recommended amount was based in part on the fact the state had to pay out of pocket for the drugs and if a virus becomes resistant, the antiviral courses would be wasted ."It's not a silver bullet," Manley said. "If we ordered a million doses, and it becomes resistant, that is a lot." Hall, the HHS spokesman, said the federal government left it up to the states to decide whether they needed to purchase the full amount available to them, and some opted against it. Jeff Levi of the Trust for America's Health, which compiled a recent state-by-state report on the stockpiling of antiviral medicine, criticized that decision and said the federal government should have purchased the full amount itself. "I think what we're seeing with swine flu, with the virus being susceptible to the drugs in the stockpile, I think it demonstrates the importance of doing this," Levi said.