Is It Ever Too Late to Get the Flu Vaccine?

When Does the Flu Peak and When Is a Vaccine Most Helpful?

Woman with the flu
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If you live in the United States, you probably start hearing about flu season sometime in the late fall or early winter. You might wonder if there is a set time that is called flu season. Are there certain months of the year that have this designation, and is there a peak in flu season?

Actual flu season can vary. It depends on when the influenza virus starts circulating in your area and when the levels of flu in the community rise above and fall below a threshold set by the U.S. Centers for Disease Control and Prevention (CDC).

An understanding of the patterns and the best times to get a vaccine may help prevent you from getting the flu.

A Typical Flu Season

Flu season in the United States and Northern Hemisphere usually occurs between October and May. Flu activity often starts to increase in October and will continue to rise until it reaches "peak" levels. Peak simply means the highest level of flu activity across the country. This most often occurs sometime between December and March. Between 1982 and 2016, flu activity peaked most frequently during the month of February.

It is actually possible to get the flu (influenza) any time of year, but it is much more common during "flu season." The influenza virus circulates around the world all the time but does spread more easily during the cold months. This occurs both because the virus spreads more easily through cold, dry air and because people are inside spreading germs more often during the winter months.

When Should I Get the Flu Vaccine?

The best way to protect yourself from the flu is to get a flu vaccine every year. They are typically available as early as August. It might seem strange to get your flu vaccine at the end of the summer, but getting it before flu season actually gets started is really ideal, partly because the flu vaccine takes two weeks to provide protection.

Getting your vaccine sooner than later is ideal. However, that doesn't mean getting it later in the season is too late! If you are concerned that getting it too early will mean that the protection will fade, don't be. The flu vaccine provides protection for about a year, so getting it early will cover you for the entire flu season.

The flu vaccine provides protection against 3 or 4 strains of influenza that researchers believe are most likely to circulate during flu season. Because they have to be manufactured six months in advance, the strains in the vaccine aren't always an exact match to the strains that circulate and make people sick each year. However, studies have shown that people that are vaccinated are less likely to suffer from serious flu complications and severe symptoms than those who are not vaccinated.

If you think the flu isn't much more than just a bad cold, you are wrong. It kills thousands of people each year in the U.S. alone. It takes the lives of over 100 children each year as well. A vast majority of those children are unvaccinated and many were previously healthy. The flu is a terrible disease that shouldn't be taken lightly.

Vaccination is the best way to protect yourself and your family.

The vaccine is recommended for nearly everyone over six months old. If you are in a high risk group, vaccination is even more important.

When Is It Too Late to Get the Flu Vaccine?

Believe it or not, there really isn't a time that is "too late" to get a flu vaccine. As long as the influenza virus is making people sick in your community, it's worth getting vaccinated against it.

Some people think that if they get the flu, there's no reason to get the flu vaccine. But even that isn't accurate. There are usually multiple strains of the influenza virus circulating each year. Just because you get a strain of influenza A in December, doesn't mean you can't get a strain of influenza B later in the season.

The bottom line is, get your flu vaccine. If you haven't gotten it yet and the flu is peaking in your area, go get vaccinated today. It won't provide full protection for two weeks but it could still prevent you from getting sick.

What Else Can I Do to Prevent the Flu?

For those who can't get the flu vaccine or those who refuse to, take everyday precautions like washing your hands (a lot), use hand sanitizer when soap and water aren't available, avoid touching your face if at all possible, and try to keep your distance from people that you know are sick.

Unfortunately, the flu is contagious a full day before symptoms appear, so people that have it are spreading it to others before they know they are sick.

Pay attention to news reports and those around you. If flu activity is high in your area, that means more people are sick with influenza than usual and you have a higher likelihood of getting it. Do what you can to keep yourself and your family healthy this year and every year. And if you aren't sure if a flu vaccine is right for you and your family, talk to your health care provider.


Key Facts about Influenza (Flu) | Seasonal Influenza (Flu) | CDC.

Get Vaccinated | Seasonal Influenza (Flu) | CDC. 

Take everyday precautions to protect others while sick. Centers for Disease Control and Prevention. Published September 9, 2016. 

Take time to get a flu vaccine. Centers for Disease Control and Prevention. Published May 25, 2016. 

Vaccine Effectiveness - How Well Does the Flu Vaccine Work? | Seasonal Influenza (Flu) | CDC.