Preliminary results from two studies published online last week by the New England Journal of Medicine (NEJM) show that a single dose of the H1N1 vaccine will offer protection for most adults within three weeks of vaccination [1-2]. This is good news in the fight against H1N1, since the vaccine won’t be ready until the start of flu season. On Sunday, Health and Human Services Secretary Kathleen Sebelius said that some vaccine may be available as early as the first full week in October [3].