Flu Shot Effectiveness

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A new government report shows the flu shot was effective only nine percent of the time in those 65 or older against the most common and dangerous flu bug. Dr. Cara Christ, the Chief Medical Officer for the Arizona Department of Health Services, will discuss the flu shot and its effectiveness.

Ted Simons: A new report by the centers for disease control and prevention shows that this year's flu vaccine were effective against the harshest strain of the virus in only 9% of those aged 65 or older, and here to help us make sense of these somewhat discouraging numbers is Dr. Cara Christ. She's the chief medical officer for the Arizona Department of Health services. Good to have you here and thanks for joining us.

Dr. Cara Christ: Thank you.

Ted Simons: And first of all, are these surprising numbers to you?

Dr. Cara Christ: We were surprised when we saw the report. Every year the CDC does a vaccine efficacy study where they determine whether the strains that they put in the vaccine were effective against what was circulating in the communities, and so, we were surprised to find out that, that those over age 65 were so, so, so -- didn't amount as good 6 a response as we would have anticipated.

Ted Simons: Is that unusual?

Dr. Cara Christ: It is not quite as unusual if you were going to see that in a population, it would be the elderly population. Those over 65, tend not to mount as good of immune response, while the numbers were surprising it makes sense.

Ted Simons: This is the harshest strain, it was 27%, was the number effective against all three strains. And apparently, the lowest is about, in about ten years for those numbers. And is that just what happens when you have got viruses out there that do their thing?

Dr. Cara Christ: Yes, and viruses do all types of things, and overall, the vaccine was a really good match for what we saw circulating in the communities this year. And for the, the efficacy portion of it, how well the vaccine worked against those virus, it was a little surprising, but the viruses mutate as they tend to move through the communities. And so, sometimes they figure out ways to get around that.

Ted Simons: And all age groups and numbers, 56% effective, is that more of a normal range for all age groups?

Dr. Cara Christ: That's more of a normal range.

Ted Simons: And still, though, someone is going to hear this. And they are going to say, why should I get, especially if you are over 65 years of age. Why should I have -- 9%, that's pretty low.

Dr. Cara Christ: Right. And you know, that, the flu vaccine is still the, the best protection that we have against influenza. And we always like to say that influenza is predictably unpredictable. You never know what the season will look like or how severe it will get, and especially in young children, and in babies, and then those over the age of 65, they can develop severe complications from influenza, and so it's really important for people to get vaccinated.

Ted Simons: And as far as -- 24,000 a year die because of the influenza? This is serious business.

Dr. Cara Christ: Right. And the influenza, while most people just think it's a common cold or some mistake the G.I. symptoms as the flu, when you get hit with actual influenza, you feel like you've been hit by a bus. You have muscle pains. You are really sick.

Ted Simons: And hospitalization rates, again, from what I looked at the research, high of 65 plus, highest in a decade or so. And is there something going on out there as far as treating or, or the vaccines or a combination of all or is it just, as you say, unpredictable.

Dr. Cara Christ: I think that it's unpredictable, and for the last few years, when we always monitor influenza, we have surveillance that we're always doing. For the last few years the predominant strain has been the h1n1. And this year, that's not what we were seeing, and we were seeing a new strain within the community. That may play a role. People haven't been exposed to it like they have been with H1N1.

Ted Simons: It would seem, and this is just my conjecture here, and I am playing doctor. And that if you are 65 or over, you have lived through a whole lot of flu and is a lot of viruses. Whether got sick or not, the fact is that you've been exposed. I would think that they would do the best against vaccines, with the vaccines.

Dr. Cara Christ: You know, sometimes that, that's the case. Like with the -- with the h1n1, they had seen it so they did not have as bad of a response. The problem is as you get older, your immune system wanes or is not as effective. So when you see something new, you are not able to mount as active of a response as those that are younger are.

Ted Simons: And as far as the, you mentioned the strains mutate relatively quickly. How -- can you have something ready going in October and November and by January and February, it's a whole different beast?

Dr. Cara Christ: Normally, not like throughout the entire country but what we do monitor for, is things that may change the severity, so they are better adapted to people and they grow better, or things that may become anti-viral resistant. So they become resistant to the medication that we can give to you make it better.

Ted Simons: Interesting.

Dr. Cara Christ: So we do monitor those types of mutations.

Ted Simons: When it comes to the vaccines in and of themselves, first, when do you know? Obviously, before flu season starts and right at the start, we get the pitch, got to get t but, when did, when did, when was the stuff baked? When did they know that this is what we have got to get out there?

Dr. Cara Christ: We watch worldwide so we work with the CDC, the CDC works with the world health organization, and we watch as it moves through Asia and through Australia and through South America, and you could see what strains are circulating there. And that's what they used to make our flu vaccine for in season. So, they are kind of already starting to monitor what's going on in other parts of the world.

Ted Simons: So, there a lot of guesswork? It seems like there might be some?

Dr. Cara Christ: There is a bit but they have got a really good formula for how they determine it, and it's a good match except for the very unexpected things like h1n1.

Ted Simons: And Maricopa County in particular, but just Arizona as a whole, is this great, this particular flu season? Worse than usual?

Dr. Cara Christ: I would say worse than usual. But, not quite as bad as 2009.

Ted Simons: Ok. So, and how long will this particular flu season last?

Dr. Cara Christ: You know, it's starting to decline. We hate to say anything because it could pick up here in just a bit. But, we are seeing a downward trend in the numbers reported to us.

Ted Simons: And with that downward trend, with it so late in the season, is it wise to get a flu shot?

Dr. Cara Christ: You know, right now, we're not encouraging everybody to get the flu shot. If you think that you are going to travel, come in contact with that, talk to your health care provider, the flu vaccine is harder to find because we are so late. But we always encourage everybody, if you are at risk of getting influenza, get the vaccine.

Ted Simons: Even if it's 9% effective for 65 and older, if you are 65 and older you don't want to be the 9%?

Dr. Cara Christ: Right, and you want to do everything that you can to protect yourself.

Ted Simons: All right. Very good. Good to have you here. Thanks for joining us.

Dr. Cara Christ: Thank you.

Dr. Cara Christ:Chief Medical Officer, Arizona Department of Health Services;

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