Lethal virus more threatening to public health than Ebola: Influenza

Those numbers disappoint David Cennimo, an infectious disease physician and assistant professor of medicine and pediatrics at Rutgers New Jersey Medical School. Cennimo tells Rutgers Today that getting an annual flu shot is far more important than many people realize.

How dangerous is the flu, and why does it deserve our attention?

David Cennimo: A lot of people think of the flu as a pretty mild illness, right up until they get it themselves, and then they see how severe it can be. I have treated severe cases where patients have been in intensive care on a ventilator. In one case I remember from my medical training, the patient developed a severe secondary infection and died. The thing that struck me is people saying, 'I don't understand; it's only the flu.' When you see a severe case, as I have, you get a whole new respect for the illness.

What about people who consider themselves healthy? What incentive do they have to be vaccinated?

Cennimo: First of all, they're helping to protect those who are most vulnerable -- the very young, the very old and those with other medical conditions, including cancer and suppressed immune systems. People at highest risk are better protected if those around them are also protected. So are the rest of us. Even if you're the young 35-year-old guy in the office, I don't want you in the office with me, or on the subway or the bus, because you can get everyone sick if you're not vaccinated. But even if that doesn't move you, getting vaccinated also benefits you directly. Nobody wants to get the flu. Nobody wants to miss a week of work and feel miserable, so that's reason enough for me.

There are people who insist that flu vaccinations do them no good, that they get the flu anyway. Some even claim they've gotten the flu because they've had a flu shot. How do you answer them?

Cennimo: Those are a couple of the more common arguments I hear. First, you can't catch the flu from a flu shot. The virus in that vaccine is killed. There's nothing replicating in there. You can catch influenza from someone else in the waiting room at the doctor's office or pharmacy when you go for your shot. You need to remember that it usually takes up to two weeks before vaccines take effect, while the incubation period of influenza is only a couple of days. So in that situation, if you become infected you can get sick before the vaccine has a chance to work. That's an incentive to get vaccinated as early as possible in the season, before lots of people around you are sick.

As for people getting the flu anyway despite being vaccinated, admittedly the vaccines are not always 100 percent effective, so it is possible. But usually people who make this complaint say, 'I get the flu every year.' I usually then realize they've never had the flu. We're all going to have one or two colds this winter, and they could be accompanied by aches and a fever. That's not influenza, which is far more severe, but they think it's flu and claim the shot didn't work.

Some people are also concerned about allergies to the vaccine, including egg allergies. This actually is very rare in the population but can happen. If they believe they are allergic, they should discuss it with their physician and may need a different type of vaccine. We generally hear from people worried about egg allergies. The research suggests that if you can eat scrambled eggs, you can safely get a flu shot.

There are different forms of flu vaccine, including a nasal spray for people who don't like shots. What can you tell us about the spray vaccine?

Cennimo: The nasal flu vaccines are really interesting because unlike the injectables they are a live attenuated virus. The virus is alive but mutated in a way that can only replicate where it's cold so it can't go to your lungs and make you sick. It's indicated for people from ages 2 to 49 as long as their immune systems aren't compromised, because theoretically giving live virus to immunocompromised people presents a higher risk for them.

There actually are new data showing an advantage to giving 2-to-8-year-olds the nasal spray instead of an injection. They seem to get better antibodies, better protection -- plus you're not sticking them with a needle. But both the spray and injectable vaccine are fine. Any influenza immunity you get is good influenza immunity.

In this season when Ebola is so much in the news, how do you feel about all the attention is it getting?

Cennimo: Ebola is very scary. But people in the United States are frightened of Ebola for statistically very little good reason. It's fear disproportionate to the risk. Influenza has far too little fear based on the risk. It's fascinating to me to see social media panic and listen to people worried about Ebola who have never had an influenza vaccine, where statistically the thing you will get this year is influenza. You'll probably do yourself and those around you the most good by getting a flu shot.