Got Sick Even Though You Had a Flu Vaccine? What Gives?

Did you get a seasonal flu vaccine last year and still suffer flu-like symptoms? Is it making you think twice about getting vaccinated again this year?You may want to reconsider, because the bug you came down with could have been something other than the flu. And the flu vaccine still likely protected you against getting sick with its intended target: influenza.Seasonal flu, or influenza, is a viral respiratory infection that mainly affects the nose, throat and lungs. Common symptoms include fever, chills, headache, fatigue, aches, sore throat, cough and runny nose, although not everyone with the flu will suffer from all of these.There are three major categories of flu viruses, but only two cause the breakouts we see each cold season. These are influenza A and B. Influenza A has over two-dozen unique subtypes, and influenza B has several different strains. From year to year, these different flavors of influenza mutate. The Match GameThe flu vaccine works by exposing you to dead or weakened flu virus, which helps prep your immune system to fight against the real thing (for more information, click here). Each year, the Food and Drug Administration recommends vaccines against specific versions of influenza A and B based on what they think will be the most likely to hit for the season. The flu vaccines generally cover three strains in total although, for the first time, some of the vaccines available in the 2013-2014 season will protect against four strains.Some years, the FDA’s estimate is spot-on and the vaccine tracks well with the flu that is actually going around. In other years, the match is a poor one, which means the vaccine won’t offer as much protection.This doesn’t mean the flu vaccine won’t work at all in these off years. If the strains covered by the vaccine are closely related to the circulating flu, it might still offer some defense against getting sick. But if the vaccine and the actual flu you’re exposed to don’t match at all, the vaccine unfortunately won’t work.When the “Flu” Isn’t the FluLast year, the 2012-2013 flu vaccine was a good match for the viruses that were actually infecting people, which means that if you had a shot, you should have been well protected. So why did you still get sick?Even in good years, the flu vaccine works better for some people than others. It generally is most effective in children over 2 years and in young adults, and least effective in people over 65 or who have weakened immune systems.If you’re young and healthy and got vaccinated but still had flu-like symptoms, your vaccination may have come too late. It takes two weeks for the vaccine to be effective, so if the flu virus gets to you either before your vaccination or in the two weeks following it, you could still come down with influenza.It’s also possible that you didn’t have the flu at all. Many illnesses cause the same miserable respiratory irritations, fevers and chills as the flu, including the common cold and many unnamed viruses.According to YouBeauty advisor and internist Dr. Beth Ricanti, an important habit to protect both against flu and other illness is to wash your hands regularly. And to protect people around you, make sure that you aren’t coughing or sneezing onto your bare hands. Instead, either use a tissue or cover your mouth with your elbow or upper sleeve.If you do end up with flu-like symptoms—even if you don’t have the actual flu—Dr. Ricanati recommends rest, hydration and managing fevers. Whether you should check with your doctor depends on how bad you feel and whether you have health issues that make you vulnerable to complications.“Certainly it depends on the individual,” said Dr. Ricanati. “If it’s the worst you’ve ever experienced, if it feels really different, if it’s going on for several days—if anything about it is untoward or bothersome at least call your doctor if not actually go in.”“Taking it to another level, if you have underlying illnesses, then it really matters that you check in with your doctor.”