We've all heard the advice to get the flu shot each fall. But is it really that important to do so?
The short answer: definitely yes.
Here's why the flu shot is so important.
What is the flu vaccine?
Although the precise formulations of the vaccine change every year, the basic foundations of the vaccine remain constant. The shots are either made with flu viruses that have been inactivated, which means they’re not infectious, or — in the case of recombinant flu vaccines — they're made without viruses at all. This means that you can't get the flu from any type of shot.
Depending on the year, both three-component or four-component vaccines are available. Three-component vaccines defend against three types of flu virus: an influenza A (H1N1), another influenza A (H3N2) and an influenza B virus. The four-component vaccines protect against these same viruses, plus an additional B virus. Your doctor will recommend you get either the three- or four-component vaccine depending on your age, the health of your immune system, allergies and other factors.
How is the flu vaccine selected?
According to the CDC, the flu virus is constantly changing, so it's necessary for researchers to reevaluate the expected strains each year. The exact components of the vaccine, therefore, may change from year to year. The World Health Organization assembles a board of researchers from their own collaborating centers and other key laboratories – including the CDC and the Francis Crick Institute — to determine:
- Which viruses are making people sick
- How fast the viruses are spreading
- The effectiveness of the previous vaccine
Once this information has been presented and reviewed, the FDA will make the official vaccine decision for the U.S.
Who needs the shot?
The CDC recommends that anyone six months or older get the flu vaccine. And for those who have an increased risk of flu-induced complications — like those under five years of age, those over the age of 65, pregnant women or those in nursing homes or other care facilities — it's vital to adhere to flu vaccine recommendations. There are some exceptions to the recommendations, though: Those who are under 6 months of age, allergic to the flu vaccine or allergic to flu vaccine ingredients like gelatin should not get the flu shot. And those who have had Guillain-Barré Syndrome in the past should talk with their doctor first.
It's especially important for pregnant women to protect themselves because if you get the flu while you're pregnant, the risk of complications is much higher. It's also imperative that those with the following conditions get a flu shot, because contracting the flu may worsen symptoms or lead to complications:
- Asthma or chronic lung disease
- Neurological conditions
- Heart disease
- Blood disorders
- Endocrine disorders such as diabetes
- Kidney or liver disorders
- Metabolic disorders
- Damaged immune system
- Extreme obesity
The timing matters
So you know that you need a flu shot, but some questions remain: When should you get it? And is getting the shot at one time of year more effective than another? The answers are complicated.
It's always better to get the flu shot than not, regardless of when you get it. But in the ideal scenario, you'd get the shot before the flu starts to spread each year. According to the CDC, that’s in October. And because children age six months to eight years will have to get two doses four weeks apart the first season they’re vaccinated, it's beneficial to begin their vaccination process a bit earlier.
That said, depending on the year, the flu shot may still be effective even if you get it in January or later, so you should never think it's too late to get the shot. It’s probably still worth it, since the flu continues to spread throughout the winter.
If you're unsure about whether or not to get the flu shot based on your health profile, check with your doctor. There are few sure things in life, but getting the flu shot each year is pretty close to one of them.
It might just save your life — and possibly the lives of others, too.