A lot of people are wondering, Just how dangerous is the swine flu virus? (More formally known as, 2009 H1N1.)

The word from epidemiologists is: Not very dangerous, for most of us.

However ….  It’s quite dangerous to people falling in certain categories.  Watch out if you are: a pregnant women, a baby, elderly, immune-compromised, morbidly obese.  Or, if you have: any lung disease or disorder, an underlying chronic health problem.  (More details on this at the federal flu website.)

H1N1 virus particles invading body tissue. (CDC)

The easiest way to think about swine flu is that it’s remarkably similar to regular flu, except it spreads more rapidly.  Most people get only mildly sick and are better in three days or so.  I was surprised to hear epidemiologist Jeff Duchin of Public Health Seattle & King County go so far even as to urge most of us not to call the doctor.  There’s too much over-crowding as it is.

But there is some research that indicates this virus might be a little more dangerous than seasonal flu—especially for those in the “vulnerable” list I mentioned above.  For example, one team of researchers (at Imperial College in London) found the novel H1N1 flu virus lodges deeper in the lungs than regular flu virus.  That enables it to cause more severe lung infections and may account for some of the fatalities.  But it also is less aggressive in the nose and throat – making most infections less severe.

The message from this is, if you notice complications, such as breathing problems, don’t delay seeking medical help.  The best way I’ve found to sort all the usual questions is via Children’s Hospital of Atlanta, on their website.

Other tidbits:

• The vaccine tests are full of good news. It appears to be highly effective and can be given in a single dose.
• The first vaccine shipments may arrive on time, or even in early October.

Other recent posts and stories:

• “Schools ready for swine flu?” on this blog
• “Have Swine Flu, Should I Call a Doctor? Maybe Not” on KPLU
• “Swine Flu Vaccine Could Be Major Help, If It Were Ready” on KPLU