There have been several new reports evaluating the most recent numbers on 2009 H1N1 pandemic flu that I wanted to share with you.

First,  good news: experts are not predicting  third wave of infections and the spread of the virus is still decreasing. However, millions of new infections are still occurring each month in the U.S., including 18,000 hospitalizations and 310 deaths in February (see WebMD for epidemiological estimates of total numbers between April 2009 and February 2010).

Here is a CDC chart breaking down the numbers by age groups. As you'll see, the H1N1 virus affects younger people (<64 years of age), which is different from seasonal influenza. Also, the virus is more severe for pregnant women.

But, among this unpleasant news (though not unexpected based on last Fall's investigations), there is more good news: vaccinating children for H1N1 decreases community infections by ~60% (according to a Canadian study).

An estimated 86 million Americans have been vaccinated aginst 2009 H1N1, and the effort has been considered a success. The H1N1 vaccine is still available to the general public (though originally limited to high risk groups, availability was opened in January). It is estimated that roughly half the U.S. population is immune due to infection/exposure/vaccination, but this is not expected to be enough to protect against another wave and this virus has been unpredictable though now preventable.