What’s the difference between the usual flu and the “swine flu”/2009 H1N1 flu?
The worldwide outbreak of a flu strain called “2009 H1N1” is important because it is brand new to most people in the world today. Its genes and protein markers are different from the usual, “seasonal” flu, so that any previous episodes of flu or previous flu vaccines a person may have had will probably not protect against this new virus. Those age 60 years and older have a reasonable chance of previous exposure, and therefore the H1N1 strain typically causes less severe flu illness in older adults than in children and younger adults. Many more people will come down with flu this season than is usual, and as a result of that many more people will get very sick and even die from the flu than is usual. The symptoms of 2009 H1N1 flu have been a little different from the usual, “seasonal,” flu. Especially in children, there is a greater chance of vomiting or diarrhea than with seasonal flu. Illness without fever is also common.
The worldwide outbreak of a flu strain called “2009 H1N1” is important because it is brand new to most people in the world today. Its genes and protein markers are different from the usual, “seasonal” flu, so that any previous episodes of flu or previous flu vaccines a person may have had will probably not protect against this new virus. Those age 60 years and older have a reasonable chance of previous exposure, and therefore the H1N1 strain typically causes less severe flu illness in older adults than in children and younger adults. The symptoms of 2009 H1N1 flu have been a little different from the usual, “seasonal,” flu. Especially in children, there is a greater chance of vomiting or diarrhea than with seasonal flu. Illness without fever is also common.
