Should I get the Flu vaccine?

Should I Get the Flu Shot?


It's going to be a bad flu season this year, so.... YES, get the flu vaccine.

(...Unless you have an egg allergy or other component of the vaccine, or had a bad reaction to a previous flu vaccine in the past, or don't believe in vaccines for philosophical reasons...If you belong to any of these groups of people, this article is not for you.)


But I hear the flu vaccine is not very effective, so it doesn't work!

That's partially true.

Flu vaccines are generally around 30-40% effective for reducing influenza like illnesses, based on previous year's research. This is in stark contrast to most other vaccines that are much more effective (compare with 90% effective for Gardasil9, or 99% for polio vaccines). Any reports or experts that you hear predicting this year's effectiveness is basically an science-based estimate, an educated guess. (It ain't over until its over, and when its over, then we'll know, but it will be too late.)

Just because something is not 100% effective, does not mean it is a waste of time to protect yourself. For example, seatbelts reduce risk of serious injury and death by about 50%. Well if it only protects me half the time, then maybe I shouldn't wear seatbelts? No, it is still better to have the protection of wearing seatbelts, than zero protection of not wearing seatbelts. Similarly, the flu vaccine may not be perfectly effective, but 40% protection is still better than zero percent protection.


I hear this year's effectiveness is only 10% effective! So it basically doesn't work at all!

Again, this is only actually maybe true, but not fully true yet.

The actual effectiveness of this year's flu vaccine is not actually not known until the end of comparing two groups of people (those that received this year's vaccine, and those that didn't receive the vaccine, and waiting to see how many got influenza this year). As you can see, you can't really know the answer of this fully, while we are still experiencing the current flu season. You have to wait until enough people get sick this year, and then compare.

The 10% you may hear in the news, is actually based on the vaccine effectivness for last year's flu season in the opposite side of the world (in Australia, the Southern Hemisphere). What happens in the other side of the world, in another time, does not always correlate to what happens on our side of the world, and in this season. So basically, the experts are predicting something for this year, based on something that happened somewhere else, in another part of the world, where the flu seasons is often different.

So why are the experts so worried? Well, although the flu strains on the opposite side of the world are often different, and behave differently, this year's predominant North American flu strain (H3N2) is turning out to be the same as last year's Australian flu strain. (Remember, winter in Australia, is summer in Canada) Last year's Australian flu was bad, and the vaccine was only 10% effective for the predominant H3N2 flu strain. However, the CDC has tested this year's predominent H3N2 flu strain to what's in this year's vaccine, and the found that it matched very well. So why is there a difference between genetic matching and actual vaccine effectiveness? This is because what is done in a laboratory does not always correlate to the real world data (how many actual people don't get the flu with the vaccine, compared to how many that do without the vaccine). There are also other flu strains circulating (some of which is not included in the flu shot). The flu virus is notoriously unpredictable.

Is Australia 2017, like Canada 2018? Well, you guess is as good as mine. Expert still advise people to get the flu shot, because the flu virus is notoriously unpredictable (they mutate). Predicting the future is not an exact science. Just look at weather predictions, they're pretty good, but not perfect.

30-40% protection from the horrible flu (fever, sore throat, coughing, muscle aches, runny nose, wipe-out fatigue for weeks) is still better than zero protection. Even if you still end up getting the flu, the body will be better prepared to fight it off, and you will have a milder form, or shorter duration of the flu. You will also protect those around you from getting the flu from you (ie. your baby, your senior parents or grandparents).