--- title: CDC Says Flu Shots May Not Be Very Effective This Year description: A sample of flu cases so far this season shows that the current flu vaccine may not be effective against the common strain. canonical: https://time.com/3617759/cdc-flu-vaccine/ author: Tessa Berenson article:opinion: false article:content_tier: free article:published_time: 2014-12-04T13:33:35.000Z article:modified_time: 2026-02-22T02:34:17.420Z article:section: Health og:title: CDC Says Flu Shots May Not Be Very Effective This Year og:description: A sample of flu cases so far this season shows that the current flu vaccine may not be effective against the common strain. og:url: https://time.com/3617759/cdc-flu-vaccine/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt7854909363bfce61/6987622d8e06019066457d9f/flu-influenza.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Flu vaccines og:type: article twitter:card: summary_large_image twitter:title: CDC Says Flu Shots May Not Be Very Effective This Year twitter:description: A sample of flu cases so far this season shows that the current flu vaccine may not be effective against the common strain. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt7854909363bfce61/6987622d8e06019066457d9f/flu-influenza.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # That Flu Shot You Had May Not Work This Year  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson Dec 4, 2014 1:33 PM UTC  Flu vaccines. File photo dated 05/10/09 of a nurse preparing to give a patient a shot from a hypodermic needle, as pregnant women are among those being urged to get the flu vaccine in a major public health drive. Issue date: Monday October 6, 2014\. People with existing health conditions and parents of young children are also being targeted by medics seeking to encourage widespread immunisation against the illness ahead of the winter. See PA story HEALTH Flu. Photo credit should read: David Cheskin/PA Wire URN:21112040 Flu vaccines. File photo dated 05/10/09 of a nurse preparing to give a patient a shot from a hypodermic needle, as pregnant women are among those being urged to get the flu vaccine in a major public health drive. Issue date: Monday October 6, 2014\. People with existing health conditions and parents of young children are also being targeted by medics seeking to encourage widespread immunisation against the illness ahead of the winter. See PA story HEALTH Flu. Photo credit should read: David Cheskin/PA Wire URN:21112040David Cheskin—PA Wire/AP  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson Dec 4, 2014 1:33 PM UTC The Centers of Disease Control and Prevention (CDC) have warned doctors that flu vaccines may not be effective against the most common strain of flu circulating in the U.S.. [According to Reuters](http://www.reuters.com/article/2014/12/04/us-usa-flu-idUSKCN0JI00T20141204), the U.S. health agency issued an advisory to doctors Wednesday saying that of the flu samples they had taken between October 1 and November 22, less than half were good matches for the current flu shots. The flu shots will still protect against certain strains of the flu, and can help reduce the risk of complications even among the strains that have mutated. \[[_Reuters_](http://www.reuters.com/article/2014/12/04/us-usa-flu-idUSKCN0JI00T20141204)\] ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3617759/cdc-flu-vaccine/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3617759/cdc-flu-vaccine/"},"headline":"That Flu Shot You Had May Not Work This Year","datePublished":"2014-12-04T13:33:35.000Z","dateModified":"2026-02-22T02:34:17.420Z","description":"You should still get vaccinated","url":"https://time.com/3617759/cdc-flu-vaccine/","keywords":["medicine","flu","CDC","vaccine"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt7854909363bfce61/6987622d8e06019066457d9f/flu-influenza.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Tessa Berenson","jobTitle":null,"url":"https://time.com/author/tessa-berenson/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt7854909363bfce61/6987622d8e06019066457d9f/flu-influenza.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Flu vaccines","caption":"Flu vaccines","creditText":"David Cheskin—PA Wire/AP","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/medicine/","name":"medicine"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3617759/cdc-flu-vaccine/","name":"That Flu Shot You Had May Not Work This Year"}}]}] ```