Flu Vaccines Work to Help You Avoid the Flu

Kids and the Flu

It is time to get your flu vaccine.
Flu vaccines may be a bit delayed this year, but there still should be plenty of time to get your kids their flu shots. Photo by Micah Young/Getty Images

The latest recommendations from the CDC are that everyone who is at least 6 months old get a flu vaccine each year.

A yearly flu vaccine is the single best way to help avoid getting sick with the flu.

Still, many people don't routinely get a flu vaccine.

While some people say that they don't "believe" in getting a flu vaccine or are scared about flu vaccine myths, others are concerned about flu vaccine side effects, and some simply don't think that they work.

Three Great Reasons to Get a Flu Shot

There are plenty of great reasons to get a flu vaccine each year.

Three very simple reasons to get your kids vaccinated are that:

  1. it will help keep them are from getting the flu
  2. it will help keep your family from getting the flu
  3. it will help keep everyone else from getting the flu

How? If your kids don't get the flu, they won't bring it home and spread it to others. This is like the vaccine herd effect that we see with other vaccines.

Of course, there are plenty of other good reasons.

If avoiding a life-threatening, vaccine-preventable disease wasn't a good enough reason, how about avoiding a prescription for Tamiflu because you didn't get sick with the flu?

Or avoiding missed days off from work and school?

And so far this year, the CDC reports that "laboratory analysis of influenza viruses to date suggests that the majority of viruses circulating worldwide in the past few months are similar to 2015–16 vaccine viruses," so unlike last year, we should have a flu vaccine that really works well.

Do Flu Vaccines Work?

If you get a flu vaccine and still get sick, does that mean that your flu vaccine didn't work?

Of course not.

The flu vaccine only protects you against the flu. Unfortunately, there are many other things that can get you sick during cold and flu season. Your flu vaccine won't protect you against a cold, allergies, a sinus infection, bronchitis, or flu strains that aren't in the vaccine.

A flu vaccine will do a pretty good job of protecting you from the flu strains that are going around during flu season though.

Flu Vaccines Really Do Work

Since the 2004-05 flu season, estimates of flu vaccine effectiveness have ranged from 10% to 60%.

The average flu vaccine effectiveness has been about 41%. When there is a good match between flu virus strains, as there is in most years, the flu vaccine is about 50 to 60% effective.

When there is a poor match, the flu strain that is going around simply wasn't picked to be in the flu vaccine, then the vaccine is less effective. The flu vaccine can also be less effective when there is a drifted strain of flu going around - it's in the flu vaccine, but it changed enough from the flu vaccine strain to make the flu vaccine less effective.

In most studies, and as defined by the CDC, flu vaccine effectiveness is simply a measure of your chances of catching the flu after getting a flu vaccine.

How do they test if flu vaccines work?

Commonly, researchers test people who come in for a respiratory illness during flu season, do a flu test, and compare vaccination rates between those who test positive and negative for the flu.

How are flu vaccines working this year?

Many people will be happy to know that this year's flu vaccine is working well and is at least 60% effective.

Flu Vaccine Benefits

Getting a flu vaccine has many other benefits that aren't measured by those simple studies, though, which can help you understand why getting a yearly flu vaccine for your family is very important, especially when you consider that flu vaccine reactions are typically mild.

During the 2013-14 flu season, in which only about half of people got vaccinated and the flu vaccine was about 51% effective, the CDC estimates that getting a flu vaccine "resulted in an estimated 7.2 million fewer cases of influenza, 90,000 fewer hospitalizations, and 3.1 million fewer medically attended cases than would have been expected without vaccination."

Flu shots were found to be 63% during the 2015-16 flu season. Unfortunately, FluMist, the nasal spray flu vaccine was only 3% effective, which has led to a new recommendation that it not be used next year.

And even when the flu vaccine is only 50% effective, you shouldn't think about it as coin flip odds. In addition to the 50% chance of simply not getting the flu, even if you did happen to get the flu, your flu vaccine might:

  • lead to a flu illness with milder symptoms
  • decrease your chances of being hospitalized with the flu
  • reduce your chances of developing the most serious, life-threatening flu complications, such as stroke and heart attacks. In fact, when you look at pediatric flu deaths, tragically, almost all are unvaccinated. Flu shots are also said to be about 80% effective at preventing death in elderly persons.

As with other vaccines, getting protected with a yearly flu vaccine can help protect those around you who can't be vaccinated, including newborns and infants who are under six months of age during flu season.

Most importantly, remember that even when the flu vaccine isn't a good match and isn't as effective as in other years, "some protection is better than no protection at all."


CDC. Estimated Influenza Illnesses and Hospitalizations Averted by Vaccination — United States, 2013–14 Influenza Season. MMWR. December 12, 2014 / 63(49);1151-1154

Press Release: Flu Vaccine Nearly 60 Percent Effective

CDC. Seasonal Influenza Vaccine Effectiveness, 2005-2015. Accessed September 2015.

Cohen, Steven A. Influenza Vaccination in Young Children Reduces Influenza-associated Hospitalizations in Older Adults, 2002–2006. J Am Geriatr Soc. 2011;59(2):327-332.

Epidemiology and Prevention of Vaccine-Preventable Diseases. The Pink Book: Course Textbook - 13th Edition (2015)

Ferdinands JM, Olsho LEW, Agan AA, et al. Effectiveness of influenza vaccine against life-threatening RT-PCR-confirmed influenza illness in US children, 2010-2012. J Infect Dis. 2014; 210(5):674-683.

Kim, Tae Hyong. Seasonal influenza and vaccine herd effect. Clin Exp Vaccine Res. 2014 Jul; 3(2): 128–132.