Ask Dr. Hallberg: Flu season and a pneumonia vaccine

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Advertisements for flu vaccines are one of the signs of the season, along with cooler weather and back-to-school shopping.

The ads have popped up around the state in recent weeks. This year, the federal government has recommended that everyone over the age of six months get a flu shot.

Health experts say they're cautiously optimistic about this year's flu season, now that the World Health Organization has declared the H1N1 swine flu pandemic officially over.

MPR News medical analyst Dr. Jon Hallberg joined All Things Considered's Tom Crann on Wednesday to provide an update on this year's flu vaccine, along with information about a shot to prevent pneumonia.

Hallberg is a physician in family medicine at the University of Minnesota and medical director of the Mill City Clinic in Minneapolis.

Is there a health topic in the news that you'd like to know more about? Send a question or topic to Dr. Hallberg.

Tom Crann: So, first to the flu shot. We all remember last year's shortages, especially because of H1N1, needing to get two shots. What do we need to know this year?

Dr. Jon Hallberg: The shot this year, like every year, has three different ingredients in this particular recipe. Two of them are from Australia originally. One is from California. The one that's from California is the H1N1 strain that we saw last year, so people will not need two shots this year. It's sort of three-in-one, and one of those ingredients is what gave us so much fear last year.

Crann: If you got one last year, though, you've got to get another one this year, right?

Hallberg: That's the recommendation, absolutely. There's enough change, it seems, from year to year, and not everybody got the shot last year. So the recommendation is that all of us over six months [old] would be well advised to get one.

Crann: The average number of deaths, they always cite about 36,000 nationally a year from influenza. Is that true?

Hallberg: That's the number that we hear, and the CDC this year came up with an article that reminded us that that is simply the average, that the range might be anywhere from as low as about 7,000 in this country to as high as 50-some thousand. So it's important that we just keep that in mind, that when we hear that, that is simply an average from year to year.

Crann: When we hear of people dying from the flu, can we generalize about what they're actually dying from?

Hallberg: The vast majority of the time, if someone dies from influenza, they're actually dying from pneumonia. And it becomes so difficult to tell the two apart that you simply get, the statistic goes with what the diagnosis was. If you had a swab done and it showed that you had Influenza A of some kind, then you probably would've died of influenza, but pneumonia is actually really more the process through which someone is dying.

Crann: So, define for us -- what exactly is pneumonia?

Hallberg: Pneumonia is simply an inflammation of the lungs where you get consolidation, and by that what they mean is you get fluid, and by fluid, it's often pus. We've got the trachea or the windpipe; we've got the bronchial tubes, the smaller branches that go off of that, and then eventually they end up in the air sacs.

And so pneumonia is a process where those air sacs are inflamed and full of fluid, and when that's happening, you simply cannot exchange oxygen and carbon dioxide. And if you can't get enough oxygen, you will simply become hypoxic, and you can die from that.

Crann: I was surprised to learn that you have a vaccination for pneumonia. Tell me how that works. Is pneumonia a bacteria? Is it a virus? What is it?

Hallberg: Well, it's all of those things. Pneumonia is, I really think of it as an umbrella term. This morning I actually looked up the definition in one of my medical dictionaries, and there are 101 different kinds of pneumonia described there. The vast majority of them are caused by either viruses or bacteria.

The shot that you mentioned is something we've been giving for years. It's called the Pneumovax, and it's designed to go after one kind of bacteria, the Streptococcus pneumoniae bacteria, but there are 23 different variations of that particular one. And this shot really helps people protect them against that. It's not perfect. It's something like 50 to 80 percent effective, but we give this to all people over 65. And many parents know that we give a smaller version of this shot with fewer variations on it to infants when they're born.

Crann: This is not an annual shot, though, like the flu vaccine, correct?

Hallberg: Yes, and this plays into the fact that bacteria, this particular bacteria is much less likely to mutate the way that the flu virus does every year, or the fact that we get different strains on the shores of this country every year. So unlike flu, which is an annual vaccine, this is just given once at age 65 or perhaps two times before that if people have other conditions that put them at risk for getting pneumonia.

Crann: If you can get pneumonia from influenza, how do you actually vaccinate against a condition that's a symptom of other conditions or a result of other conditions?

Hallberg: This gets a little tricky. So when people get influenza, one of the big complications is that they get so sick that they're now susceptible to getting any number of things going on. Perhaps one of the worst things they can get is pneumonia. Their immune system is knocked down, and it just gets very difficult to fight something. So they can get any number of different bacterial infections in the lungs which can lead to pneumonia and ultimately kill them.

The reason we give the pneumococcal vaccine is that that is one of the most deadly strains out there. And so we're kind of hedging our bets that by giving that, people are going to be less likely to get something that can take their lives.

[[header:Crann: So when it comes to the good old flu shot, there's a possibility that it, too, could prevent pneumonia in some patients.

Hallberg: Well, in many ways that's why we give it. I think we sometimes forget why it is that we're giving these. We know that from a population-based perspective, giving a flu shot basically makes a healthier populace. It makes a healthier workplace. People are just getting sick less often. But really why are we giving it? We don't want people to get horrible things like pneumonia.

Crann: So while we all need to get just one flu shot this year, who should get a flu shot and a pneumonia vaccine, if they haven't gotten one?

Hallberg: The flu shot's pretty easy. It's anyone over the age of six months, and I think people know if they've had severe allergies to eggs, even though that now also is a little bit more debatable whether they should or should not receive that.

But the pneumonia shot's more difficult. Parents with newborns and infants know that [their children] are already getting that. Where it gets a little bit trickier is that people under the age of 65 who have immune systems that aren't working so well - they're fighting a form of cancer right now; they have HIV infection; they're smokers; they have asthma; they have emphysema, diabetes. All of those conditions put people at greater risk for getting pneumonia, and all of them should receive the pneumococcal vaccine.

Crann: From what you've heard in the clinic, when it comes to flu shots this year, enough for everybody and no shortages like last year?

Hallberg: So far, so good. We got our supply already, and we've been giving those to people who've been coming in for their annual visits. Just yesterday in Forest Lake, coming back from the cabin, we saw that there was a big flu sign right in front of the Cub Foods up there. So I know that they're out there in abundance.

Crann: It's not too early to get one, then? It's not like it runs out after three months or something?

Hallberg: There's always been this concern that if you give it too early in the season, it won't last until March or April, but there, too, it sounds like more evidence is supporting the idea that, look, get it now; it's going to last the season, and then there's no rush.

Crann: Jon, as always, thank you.

Hallberg: Thank you, Tom.

(Interview edited and transcribed by MPR News reporter Madeleine Baran.)