Delays in production mean that only about three-quarters as many swine flu vaccines as expected will be available this month. In a Friday news conference, CDC immunization official Anne Schuchat said that 28 million to 30 million vaccines at most will be shipped, instead of the 40 million expected. The reason? Schuchat said there's been a slowdown in the production of antigen, a critical element of the virus, which is tougher to grow for H1N1 than for seasonal flu. "We aren't expecting widespread availability until the end of the month or until November," Schuchat said. "It will be pretty challenging to find vaccine." The delay in vaccine production comes at a bad time—the WHO warned on Friday that the H1N1 strain, which reaches further into the lungs than the seasonal flu, can cause severe viral pneumonia and encouraged doctors to treat the flu with antiviral drugs as early as possible. Swine flu outbreaks have been reported in 41 states, up from last week’s tally of 37, and the virus has claimed the lives of at least 86 Americans under 18. “These are very sobering statistics,” said Schuchat.