Can you get the flu even after you get the flu shot?

shot
The good news: Even if you became ill, the flu shot may have
decreased the severity of your illness.
Credit: Colourbox

The question: I was sick all last week with the flu, but I got a flu shot last September. How did that happen?

In any given year, the flu vaccine is roughly 60 percent effective against one of the many forms of the influenza A and influenza B viruses that cause the illness. Although not perfect, most would agree that it is a good bet to get the vaccine in order to decrease your chances of becoming ill by more than 50 percent. Because the injectable forms of the vaccine are manufactured with inactive viral particles, the vaccine itself cannot cause illness.

The challenge in developing an effective vaccine lies in predicting what viruses may be in circulation during the upcoming flu season. This is done via epidemiologic studies by public health authorities such as the World Health Organization and Centers for Disease Control, in conjunction with pharmaceutical manufacturers who make the vaccine. Because of mutations in the virus, the composition of the vaccine is frequently modified in an attempt to match its effectiveness against the most prevalent types of flu. Because flu outbreaks typically begin in late autumn or winter, vaccinations are recommended in early autumn, as it can take at least two weeks to build up protective antibodies.

During the current flu season we now know that there were two peaks of flu activity. Influenza A began circulating in December 2013, and became widespread in mid-January 2014. Just when we thought that flu season was ending, a different strain of influenza B appeared in March 2014, and has been widespread, especially in the northeast. You likely came in contact with someone who was ill and spread the virus to you while he or she was still contagious.



News
Entertainment
Sports
Lifestyle
Local

FDNY debuts new fire simulator for blazes at…

The New York City Fire Department christened its newest, state-of-the-art, custom-built simulator at its training academy on Randall's Island Tuesday.

Local

Bronx cop saves baby who stopped breathing

A Bronx police officer is credited with saving the life of a 2-month-old baby who stopped breathing Tuesday morning. Police Officer Johnny Castillo, 38, was…

Local

Brewer celebrates Women's Equality Day with voter pledge

Manhattan Borough President Gale Brewer celebrated Women’s Equality Day Tuesday by pledging to register at least five women voters before the Oct. 10 deadline. Brewer…

Local

NYPD looking for lewd D train rider

The NYPD is enlisting the public’s help to find a man they say performed a lewd act on the D train Saturday evening. The incident…

Television

'Pretty Little Liars' recap: Season 5, Episode 12,…

If you've wondered whether Ali and Bethany knew each other, you got an answer tonight: Yes, and in a very tangled way. But many lingering…

Entertainment

Cymbals Eat Guitars Have Everything to 'LOSE'

At its most basic level, a rock band can be thought of as a family, a group of people selflessly devoted to a cause. When…

Entertainment

"Bachelor in Paradise" recap: Episode 4, 'Week Four'

Some things are hard to watch in a “Human Centipede” sort of way. Other things in an “American History X” sort of way. Does “Bachelor…

Movies

Fall Movie Preview: 10 films to see this…

Despite being awards season, the next four months bring a glut of remakes, rehashes and sequels. Here are 10 that should be better worth your time.

College

When are 2014 college football playoffs? (Schedule, date,…

When and where are 2014 college football playoffs? A look at the schedule, date, TV, time for the semi-finals at championship game.

NFL

Dimitri Patterson suspended only for rest of preseason…

Dimitri Patterson ended up getting just a slap on the wrist.

Sports

Eugenie Bouchard excited for 'rowdy' fans at US…

Eugenie Bouchard is sure to endear herself to New York's tennis faithful as she tries to win her first grand slam title across the next two weeks.

MLB

MLB Power Rankings: Angels and A's still at…

MLB Power Rankings: Angels and A's still at top, Nationals climb

Wellbeing

Who is having the most orgasms?

  Single lesbians report having orgasms more often than heterosexual women but both gay and straight men still come out on top of the climax…

Home

Jonathan Adler shares his tips for a great…

Jonathan Adler took a break from boogie boarding at his beach house to tell us how to keep that Labor Day party festive.

Travel

Most popular Labor Day weekend destinations

Priceline.com released its Top 20 destinations for the end of summer, including Labor Day weekend. If you’re heading to any of these spots, expect a…

Wellbeing

Working your way to type 2 diabetes: Job…

When it comes to type 2 diabetes, a stressful job can be as risky for your health as a bad diet and no exercise. A…