January 22, 2018 – Understanding Flu


Anchor lead: Why is combatting the flu so challenging? Elizabeth Tracey reports

The flu season is hard upon us, in spite of the great number of us who receive the flu vaccine each year. What gives? Andrew Pekosz, a flu expert at Johns Hopkins, tries to make sense of the complexity for the rest of us.

Pekosz: There’s really three viruses that cause influenza as we describe it. They’re divided into type A and B, there’s only really one type B and that usually comes at the end of the flu season. For the type As, they come in two flavors: H1N1, and H3N2. And those are just simple ways for us to keep track of what the surface proteins of those viruses look like. Antibodies to H1N1 won’t protect you from H3N2, and visa versa. So they really are very different unrelated viruses that we have to keep track of.  :30

What’s happened this season is the H3N2 virus is predominant, and this one is usually associated with more severe symptoms. It’s also clear from how early the flu season began that the vaccine isn’t as protective as was hoped. At Johns Hopkins, I’m Elizabeth Tracey.