Raleigh, N.C. — The H1N1 flu dominated headlines in 2009 and became the No. 1 health story of the year as it quickly emerged as a global concern.

Complications from the H1N1 virus caused more than 75 deaths in the state. In January, H1N1 flu wasn't on the radar. By April, severe cases spread from Mexico into mostly western states.

In June, the World Health Organization declared a global pandemic. At about the same time in North Carolina, the bug spread quickly through several schools and summer camps.

Vaccine manufacturers rallied to create an H1N1 vaccine, and Duke was one of the vaccine safety trial sites.

In late September, people waited for the first vaccine shipments. Just as flu cases were peaking, vaccine manufacturers announced lower than expected dose yields. Small shipments arrived and clinics serving priority groups shut down hours after opening.

Now, as cases are on the decline, the vaccine is plentiful and available to everyone. Infectious disease experts say a third wave of H1N1 and the regular seasonal flu are still potential threats in the first months of 2010.