Synopsis: The 2014-2015 flu season started much earlier than normal and so far has been much more severe than usual. Experts explain how this year’s mismatch occurred between the flu vaccine and the predominant strain of flu, and how people can protect themselves in spite of the ineffective vaccine.

Host: Nancy Benson. Guests: Dr. Helmut Albrecht, Chief, Division of Infectious Diseases & Heyward Gibbes Professor of Internal Medicine, University of South Carolina. Dr. William Schaffner, Professor of Infectious Diseases, Vanderbilt University School of Medicine.

The Flu

Nancy Benson: If you haven’t had the flu yet this winter, count yourself lucky. This flu season started much earlier than normal, and in the Southeast and Midwest, it’s hit levels that haven’t been seen since the 2009 epidemic. In some parts of the country, schools closed when more than a quarter of the students called in sick with the flu.

Helmut Albrecht: We’ve had a remarkably bad flu season, the level of it, the quantity of it, was to the point that it overwhelmed the healthcare system.

Nancy Benson: Dr. Helmut Albrecht is chief of the division of infectious diseases and Haywood Gibbs Professor of Internal Medicine at the University of South Carolina.

Helmut Albrecht: Last year our peak was later, like we usually have it in February here on the east coast or in the Southeast. We peaked at six percent of visits to emergency rooms and private offices that act as so-called sentinel sites were influenza. Typically when we go above six percent we call it bad, this year we peaked much earlier –this was in December –and at our worst we had 25% of all office and emergency room visits being due to influenza-like illnesses which is mathematically four times as much as we would expect or where we usually peak.

William Schaffner: We’re having to bring in extra physicians to work particularly in our children’s hospital just to see the patients in a reasonably prompt period of time, and we’re having to move the less sick patients out of the emergency room into one of the clinic areas just because of the volume of patients that are coming in.

Nancy Benson: That’s Dr. William Schaffner a Professor of Infectious Diseases at the Vanderbilt University School of Medicine.

William Schaffner: We would’ve thought that by now things might’ve tapered off a little–not yet. So, this is going to be a very substantial influenza season. If there is a ray of sunshine in all of this it’s that the hospitals in Greater Nashville are managing the admissions effectively. We haven’t had an emergency because we still have sufficient beds. But it’s getting kind of tight.

Nancy Benson: In an average year, the flu may kill nearly fifty thousand people, most of them older, but this year, at least in the Southeast where the national flu season started, hospitalizations have hit children harder than adults. Albrecht says flu cases have gone down since New Year’s, but still have been three times the usual peak rate.

Helmut Albrecht: We may see another spike before we see a definite fall-off. It is coming down some, not enough to give us a breather, but it’s at least not further accelerating.

Nancy Benson: But why is this flu season so bad while last year wasn’t? Schaffner says it’s a confluence of factors.

William Schaffner: First of all, the dominant influenza viral strain causing illness out there was tricky; it mutated, it changed a bit so it’s no longer well represented in the vaccine. In other words, the vaccine is not providing very much protection. Darn. That’s not so good. And also, the strain that’s out there– this same strain is of the variety that we call scientifically H3N2 — what that means is that the sort of influenza strain that usually produces more severe illness.

Nancy Benson: The mutation of this year’s principal flu virus is the most important factor. Albrecht says the H3N2 virus targeted in this year’s vaccine was the same as last year’s, but the decision on which viruses to cover has to be made months ahead so vaccine can be produced, and Schaffner says that leaves a window of vulnerability.

William Schaffner: The influenza virus is remarkably capable to change itself. The external surface — it’s a little like saying my cousin has put on a different sportcoat, and I didn’t recognize him right away because he had that different sport coat on. And that’s kind of the way the immune system works: it recognizes the influenza virus by its external surface characteristics, and if they change, then that flu virus can fake us out. Our immune system isn’t as effective, and that flu virus can come and make us sick.

Nancy Benson: Shafner says scientists aren’t all that far away from creating a universal flu vaccine targeting the unchanging layer beneath the surface of every flu virus. Such a vaccine would be good against every flu virus and might not need a booster for decades. However, many people have misinterpreted the news that this year’s flu vaccine is a mismatch for the predominant virus. That doesn’t mean it’s completely ineffective. It still reduces your risk of having to go to the doctor for the flu by 23%, according to the Federal Centers For Disease Control And Prevention. But many people have figured it’s not worth the bother of getting a flu shot this year.

Helmut Albrecht: We aim for efficacy of greater than 60%. It’s never 100%. There’s always minor, minor changes. It’s not only the vaccine, there’s other factors that explain why you get influenza or not. But 60% is acceptable and helps us suppress flu activity, deaths, and so forth pretty well. This year it appears to be around 40% at best. It depends on what marker you use. The problem with that is, people hear this and don’t get the vaccine, which causes problems several-fold. One is you’re not protected against the other strains, which this vaccine actually protects very well against.

William Schaffner: If you get infected and sick with this dominant strain, you may have a milder illness, so you may get some partial protection and also, every flu vaccine protects against an array of different strains of influenza. And some of those other strains may become active later in the flu season, so we’ll get protection against them. So all is not lost if you’ve received a vaccine.

Nancy Benson: Albrecht says it also creates a public health problem when people shy away from flu vaccines.

Helmut Albrecht: If you have a vaccine that’s half as effective against H3N2 for instance, you actually need to vaccinate twice as many people to get the similar effect on a population level. However, if people hear that there’s a mismatch exactly the opposite happens half as many people get vaccinated, and that double whammy results in a flu season as we see now.

Nancy Benson: Albrecht says the flu is carried by tiny droplets when people cough or sneeze. So it’s wise for people who have an underlying illness or are pregnant to lower their risk of infection by avoiding crowds. And Albrecht says everyone should make hand hygiene part of their normal routine.

Helmut Albrecht: The likelihood that somebody sneezes or coughs at you in the face is actually fairly limited. So what typically happens is that people cough and sneeze onto something, or most likely their hand, and then touch the doorknob that you then touch. What follows from that is that people should a) not sneeze and cough into their hands but into their elbows or their sleeves, use disinfectant if they’ve sneezed onto something else, and people who are not sick yet can avoid getting this by you always touch something but then not touching their own face, which is actually more difficult then people think, and washing their hands or using disinfectant solution much more liberally in times when a lot of influenza goes around. Hand washing goes a long, long way.

Nancy Benson: If you do get sick, Schaffner says to resist the temptation to go to work. Stay home, he says, to avoid spreading the flu. Then call your doctor. Antivirals such as Tamiflu can be very helpful in shortening the duration and severity of your illness.

You can find out more about all of our guests on our website:

Our production director is Sean Waldron.

I’m Nancy Benson.

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