Doctor answers your H1N1 flu questions

New Haven (WTNH) - Just a couple of days ago, the World Health Organization declared the first global flu pandemic in 41 years.

Infections have climbed in the U.S., Europe, Australia and South America - with 74 countries reporting nearly 27,000 cases of the H1N1 flu.

Dr. David Katz from the Yale University School of Medicine joined Good Morning Connecticut Weekend with some personal perspective on the topic of H1N1; he just recovered from the flu.

"I can reassure people, yes we do indeed have a pandemic, but overwhelmingly, this is actually a surprisingly mild flu," said Dr. Katz. "It isn't fun- I must say I didn't enjoy having the flu over the past week, but it really is quite a mild flu."

Dr. Katz also answered some questions you posed to us on Facebook. Michelle asked, "What is the difference between Type A flu and H1N1 flu?"

"Influenza A is characterized by two surface proteins: the H and the N," said Dr. Katz. "And they change a little bit every year. That's actually called 'antigenic drift.' And that's why we need a new flu vaccine every year.

"Every now and then, usually because human flu viruses and somebody else's flu viruses- birds, pigs- get together and fraternize, they exchange proteins and we have a major change in the influenza virus, and it's called antigenic shift... It's a completely new virus, and the trouble with that is our immune system isn't prepared to deal with it," explained Dr. Katz.

Bernadette on Facebook asked, "Will H1N1 be in the flu shot we get this year in the fall?"

"The answer is yes," said Dr. Katz. "We're actually well ahead of the timeline to develop an H1N1 flu vaccine. The challenge will be in anticipation of the fall flu season, to take into account any of the potentional variations on this theme."

"There's an important message here," said Dr. Katz. "Every year we underutilize flu vaccine. I'm thinking this year people are so concerned about the flu they'll roll up their sleeves."