Tuesday, December 2, 2014

Influenza: the Risks and Why you should Get Vaccinated

This is, to a small extent, in relation to my post on Ebola. While in the United States Ebola is currently a non-issue despite the recent and, in some cases, continued panic, this year's flu outbreak is here. Though there have been comparatively few cases thus far, things are only going to get worse.

A sneeze travels further than you might think. Droplets like this can easily spread the influenza virus. 
Flu outbreaks happen throughout the world every year, with a year-round risk near the equator and seasonal risk centered around winter in both the Northern Hemisphere (November to April) and Southern Hemisphere (April to November). There are a number of theories as to why the seasons fluctuate the way they do, but I won't speculate here.

So, what is influenza?

An electron micrograph of H1N1
Influenza, aka flu, is a caused by a virus with each subtype having variants in the proteins found on the viral surface. You've probably heard of a flu outbreak being referred to as something like "H1N1". This is a designation given to describe those variations in the two major viral proteins (hemagglutinin and neuraminidase, respectively). Even if someone gets the flu and recovers, if they had, for example H3N2 and then became exposed to H5N1, they would still get sick. This is thanks to the specific nature of our immune systems. It became very good at fighting off the first virus, but it doesn't have the ability to fight off the second one. It has to start all over again. In addition, since influenza is viral there is only so much that can be done to treat it. Since we don't have broad antivirals like we do antibiotics and antifungals, treatment is pretty much limited to supportive care.

How do I avoid getting sick?

Influenza is transmitted through droplets of saliva and mucus, usually through sneezing and coughing. However, simply breathing can release minuscule drops into the air. It is also possible, however, to get the flu by touching a door handle or other surface that has recently been in contact with a sick individual. This is especially true if they aren't very fastidious about covering their mouth and/or nose. If you are sick, the safest way to contain a cough or sneeze is to cover your face with something other than your hands. This is to prevent any viral particles that come out from being transferred to other people after contaminated hands leave the virus behind when they touch other surfaces. A tissue is effective, but if you can't get a tissue, sneezing or coughing into your sleeve or the crook of your arm works as well. You can also wear a face mask.

It is also suggested that everyone take precautions during flu season. If someone is sick, keep your distance, as the closer someone is, the more likely that they will get sick as well. Wash your hands frequently or use alcohol-based hand sanitizer and avoid touching your face to prevent infection from contaminated surfaces. If you do need to be in close contact with someone who is sick, like when caring for a sick child, thoroughly clean surfaces they have come in contact with, including dishes. Wearing a face mask is also not an unreasonable option.

I've had the flu a total of once in my life, and it was an awful experience. I was seven and at the time I had been diagnosed with reactive airway disease (it can develop into asthma, thought not in my case), which caused complications whenever I became sick. A cold usually led to bronchitis, so I used an inhaler regularly for years. Much like a lot of asthma sufferers with flu, my condition worsened the symptoms, though I'm not sure whether I ended up with yet another case of bronchitis. I was so sick that water once triggered me to vomit, so I didn't drink anything for a while, which only made me much, much sicker. My father, who's a trained medic, threatened to start an IV to get me hydrated. This scared me into accepting fluids, and I slowly recovered. The strangest thing about the experience is I can't remember most of it, which tells me that I was really stinking sick. If at all possible, I never want to get influenza again, and I can't understand why more people aren't more careful about it.

Why should I get vaccinated?

Vaccination is the most effective way to prevent getting influenza. As with every year since around 2005, I have received my flu vaccine. This year it was in shot form, but in the past I have also received FluMist, the nasal spray that is now mainly recommended for children. The number of people who believe the vaccine is unnecessary really surprises me, but then again we haven't had a truly major outbreak in the years since the vaccine became available to test its effectiveness on a wide scale. The fact is that the vaccine does help the people who end up getting exposed every year, but this isn't widely reported because "generic flu" is so passé compared to, say, Ebola in the US. Yes, I am still bitter about the Ebola panic, why do you ask? Now, let's be honest, a lot of people either don't care about data or don't want to spend the time finding it and interpreting it. The data is there, so let's interpret it together:

Studies have shown that vaccination reduces an individual's risk of hospitalization for influenza by over 60%. This holds true across all ages from the very young to the elderly. It is over 70% for those under the age of sixty. If a pregnant woman is vaccinated, it reduces the risk her baby will need to be hospitalized due to flu by over 90%. Though less effective, it still reduces hospitalizations for people with chronic lung conditions by over 50%. It benefits everyone across the board and the flu vaccine is free through most health insurers and fairly cheap otherwise.

Though side effects can include low-grade fevers, aches, and a runny nose, the vaccines DO NOT have a risk of someone developing the flu. Any side effects are usually quite minor. I've had just about all of them at some point or another (I've had fewer issues from the shot than from the FluMist) and while they can be a bit irritating, they're nothing to worry about. Flu vaccines have been proven safe in just about everyone, but if you have an egg allergy you should talk to your doctor to make sure you're getting one of the vaccines that are produced without egg involvement. There are currently two available vaccines of this type (Flucelvax and Flublok).

It does remain true that the flu vaccine does not guarantee that one will never get sick as the viral strains that the vaccine protects a person from may end up being different from the one that makes the most people sick. Until we are able to produce a general flu vaccine, this will remain a risk. However, in recent years the vaccines have contained multiple strains, which make it more likely that it will prevent you from getting sick.

1918 Spanish Flu: a Reminder of Flu Dangers

An emergency hospital in Kansas during 1918
After World War I, a flu pandemic swept across the planet, killing more people than the war itself. Unlike most outbreaks where the very young and the very old die at the highest frequencies, the 1918 pandemic killed a huge number of people in their prime. It had three separate waves that occurred over a year's time, coming on the extreme ends of the normal flu season. Its unusual activity still causes worry that another pandemic could happen. Flu is easily transmissible and another outbreak like the 1918 Spanish Flu could still cause a pandemic of devastating proportions.

For further information, see Flu.gov's The Great Pandemic or 1918 Influenza: the Mother of All Pandemics.

In other news...

The Ebola vaccine is in trial. Here's hoping it proves safe and effective.

Source is the Centers for Disease Control and Prevention. Images are from Wikimedia Commons and are in the Public Domain: one, two, three, four.

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