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
International

U.N. nuclear inquiry on Iran seen making slow…

The U.N. nuclear watchdog appears to have made only limited progress so far in getting Iran to answer questions about its suspected atomic bomb research, diplomatic sources said on Friday,…

National

Violence-weary Missouri town sees second night of calm

By Nick Carey and Carey GillamFERGUSON Mo. (Reuters) - The violence-weary town of Ferguson, Missouri, saw a second straight evening of relative calm on Thursday…

National

Journalist James Foley's parents, after call with pope,…

The parents of James Foley, the American journalist killed by Islamic State militants in Iraq, on Friday called for prayer and support to free the remaining captives held by Islamic…

Local

Sharpton adapts adversarial style to de Blasio's New…

It was not the first time the Reverend Al Sharpton made his way to City Hall in a fiery mood to scold a mayor about New York City police officers…

Movies

Michael Chiklis on his football past and 'When…

Michael Chiklis remembers playing football in high school and how that prepped him to play a coach in "When the Game Stands Tall."

Music

Webcast: Watch Polyphonic Spree live on Sunday Aug.…

Polyphonic Spree singer Tim DeLaughter sits with Metro Music Editor Pat Healy for a chat and then the big band performs live. It begins on Sunday at 9:30 pm

Movies

Review: 'When the Game Stands Tall' is both…

The high school football saga "When the Game Stands Tall" fumbles around for a focus while Jim Caviezel offers the most low-key coach in history.

Movies

Girlfriend in a coma: Chloe Grace Moretz

Chloe Grace Moretz is the best cheerleader "If I Stay" could ask for. As the star of the film adaptation of the successful YA novel…

NFL

Fantasy football draft guide: How to draft your…

Many are wondering if we’re entering a new age in fantasy football drafting — one where running backs take a backseat.

NFL

Jets vs. Giants: 3 Giants storylines to watch

The Giants have plenty to work on as they reach the dress rehearsal preseason game Friday night against the rival Jets.

NFL

Jets vs. Giants: 3 Jets storylines to watch

Metro looks at three Jets storylines to watch as they play the Giants Friday.

NFL

Giants expected to work Corey Washington into first-team…

The day of reckoning for the Giants' fringe players will fall upon them Friday night against the Jets.

Sex

Big weddings may lead to long-term happiness

Dreaming of a big wedding? A new study indicates that the longer your guest list, the happier you’ll be in the long run. l A…

Sex

Online dating for every generation

Frank Jackson and his mother Maggie are like lots of modern families: They have dinner together regularly, keep each other updated on their lives —…

Wellbeing

Going green could be the key to getting…

If we could just pursue the things that would actually make us happy, we could help the environment too, according to a New York researcher.…

Tech

Siren: A new dating app that puts women…

Online dating can be brutal, especially for single women. Noting that many women hate wading through inappropriate messages and photos, two tech entrepreneurs decided to…