The flu and you: To immunize, or not to immunize?

My friend Carl suffers from Galahad Syndrome. Sir Galahad, you may recall, was a knight of the Round Table who believed that “his strength was as the strength of 10 because his heart was pure,†or at least Alfred Lord Tennyson said he did.

 Carl does have a pure heart and he is in pretty good shape for a guy our age, but he is ex-cop stubborn and refuses to take his flu shot. He sees no reason to put a foreign substance into a healthy body. Like Sir Galahad, he believes that virtue will protect him from influenza.

But virtue is no protection and purity no defense. The virus is impervious. It needs only a place to infect, to replicate and to make billions more of itself. If Carl’s immune system could speak, it would be crying out for a vaccine to give it a head start on the influenza virus that is coming. C’mon boss, give us a leg up! That is what vaccines do — they give your immune system a head start.

Flu viruses, unlike measles or polio virus, change every year. Occasionally they change in a big way to cause a worldwide pandemic, as in last year’s H1N1 outbreak, and sometimes they change only enough to be new to your immune system, as in this year’s H3N2 and influenza B.

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You have billions of immune cells called lymphocytes. Each lymphocyte of the B cell type makes a specific antibody protein that reacts with only one chemical structure — the antibodies that stick to a flu virus come from different lymphocytes than the ones that react against polio virus.

Now suppose that your body has never seen this year’s new flu viruses. In your immune system, just by chance, there will be a few lymphocytes that can make an antibody to these new viruses, but not enough to make sufficient antibody to inactivate them.  

When the viruses are detected, the few cells that make antibody against flu virus will start to divide. In two weeks there will be enough of them to make sufficient antibody to quell the virus. In the meantime you will feel like death warmed over with coughing, fever, muscle aches, secondary infections — the works.

If you have had the vaccine, those few lymphocytes that can recognize H3N2 or influenza B have already become a million, or at least a lot. They divide and populate your body over two weeks and you feel nothing.

If an infection then occurs, the antibodies from those many lymphocytes bind to the H3N2 virus particles and inactivate them. Your illness is short-lived or perhaps you do not feel ill at all.

To go from a few lymphocytes to many millions takes a lot longer than to go from a million to more millions. (The million guess is metaphorical. The point is that a few divide to become a lot and you are better off if they do that before you are infected.)

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My colleague Vincent Racaniello knows more about viruses than almost anyone. He is the founder of a blog and podcast called This Week in Virology (TWIV), which keeps tabs on virus outbreaks around the world and which you can find online. He wrote a major textbook on virology.

Vincent believes that it is essential to discuss the new flu vaccine that elicits protection against H3N2, influenza B and last year’s H1N1 with your physician. (We are scientists, not physicians so we don’t give medical advice).  The viruses are already causing disease in southern states and New York. Sometimes vaccine makers guess wrong and make a vaccine against viruses that do not survive from one winter to the next, but this year they guessed right.

Some people have the idea that the flu vaccine gives you the flu, so I asked Vincent about this.

“First of all,†he said, “the injected flu virus is dead. It can’t cause disease.† 

He went on to say that occasionally someone already infected with the flu virus might get vaccinated, but the vaccine will not have had time to take effect and that person will get sick and attribute his or her illness to the vaccine.

Finally, any vaccine stimulates the immune system, which is good, and occasionally that can give you a day of being a little achy, which is common with childhood vaccines. It is a minor irritation compared to flu, from which 30,000 people die every year.  

This is serious business and there is no reason to be one of the 30,000. The vaccine does not give you influenza. Consult your physician or health-care provider or visit the Centers for Disease Control Website at CDC.gov. I’ll keep working on Carl.

Richard Kessin, Ph.D., is professor of pathology and cell biology at Columbia University. He and his wife, Galene, live in Norfolk.