Not surprisingly, pork companies aren’t so keen on the term “swine flu.”
It’s true that you can’t get swine flu from eating cooked pork, and the disease is now passing from human to human. But the virus’s genetic signature does suggest that it originated in pigs.
President Obama and other federal officials this morning referred to the disease as the “H1N1 flu virus” Here’s what that means.
All flu viruses — human, bird, pig — have an “H” and an “N” in the name, each followed by a number (the avian flu strain that has been worrying people is H5N1, for example).
The letters refer to two proteins (hemagglutinin and neuraminidase) on the surface of the virus. The numbers refer to slight variations in the form of each protein. The variations are important, because our immune system hones in on those proteins to attack the virus.
As it turns out, human strains of H1N1 flu are also pretty common. In fact, the vaccine used for the flu season that’s just ending protected against a strain of human H1N1 virus. But unfortunately, because of differences between the human and swine versions of the flu, the human vaccine doesn’t appear to protect against swine H1N1.
Update, April 30: The WHO now says it will refer to the virus as influenza A(H1N1).
Image of a flu virus particle via CDC