States yesterday began administering up to 2.2 million doses of the nasal spray version of H1N1 flu vaccine, giving priority to health care workers, children and people who care for infants, Centers for Disease Control and Prevention Director Thomas Frieden, M.D., said today. All states have ordered some of the nasal spray vaccine, which can be taken by healthy people ages 2-49 who are not pregnant. An injectable form of the vaccine should become available next week. States are receiving the vaccine from four warehouses and allocating it to providers to administer. The amount of vaccine available and ordered in each state will be reported by the CDC each Friday. H1N1 flu is now widespread in most of the U.S., with 10%-15% of the population in those areas affected, Frieden said. A replay of the CDC briefing is available at http://www.flu.gov/live/. On Friday, the CDC released for clinicians answers to common questions about H1N1 flu vaccination.