Influenza (the flu) is a contagious respiratory illness caused by types A and B viruses that trigger a range of mild to severe illness affecting the nose, throat, and lungs. Adults aged 65 years and older, young children, pregnant women, individuals with certain health conditions (such as asthma, diabetes, or heart disease), and individuals living in group facilities (such as nursing homes) are at high risk for serious flu complications. These complications might include hospitalization or even death. Healthy people can get very sick from the flu too. Vaccination every year is the best way to protect yourself (and others) from the flu.
Do I really need to worry about the flu?
Every flu season is unique and people are affected differently from one season to the next. Why? It depends on which flu viruses (types A and B) are spreading, how well the flu vaccine is matched to the current flu viruses causing illness, how much and when the flu vaccine is available in certain communities, and how many people actually choose to get vaccinated.
How does the flu spread and when is it most contagious?
When people with the flu cough, sneeze, or talk, infected droplets can be spread, landing in the mouths or noses of nearby people. You can also contaminate yourself by touching surfaces that has flu virus on it and then touching your own mouth, nose, and/or eyes. You can pass the virus to others even before you know you are sick, beginning 1 day before symptoms appear and up to 5 to 7 days after becoming sick.
How is the flu vaccine developed?
Because flu viruses constantly mutate or change, matching the vaccine to the predicted viruses and making enough vaccine is challenging. The laboratories at the National Institute of Allergy and Infectious Diseases (NIAID) research and develop a new flu vaccine each season.
Current flu vaccines use chicken eggs. Whether or not you are allergic to eggs, therefore, is one of the questions you might be asked before you get your flu shot. Flu strains identified as the possible seasonal culprits are injected into an egg to grow and then are harvested and made into vaccines. Scientists are constantly looking at new ways to create vaccines as quickly as possible. One of the many challenges to developing flu vaccines is that animals, especially birds, carry many flu viruses. Humans have been infected by some of these animal viruses. Because humans have no acquired immunity to these viruses, the potential of causing a pandemic is a real concern.
How do flu vaccines work?
Similar to other vaccines, the flu vaccine “imitates” infection but does not cause illness, stimulating your immune system to produce antibodies that help protect you from a “real” infection. It is normal to experience minor symptoms, such as fever, after receiving the vaccine because your body is working hard to build up immunity. It usually takes at least 2 weeks after vaccination for the body to produce enough antibodies to fight the disease. That said, if you are exposed to the virus just before or after getting the vaccine, it is possible that you could get the flu because your body did not have enough time to build up adequate protection.
How do I know if I (or someone I know) have the flu?
Because the flu affects people differently, it can sometimes be hard to determine if you have the flu. Oftentimes, individuals who have the flu experience some or all of the following:
- Fever or chills (note: not everyone with the flu will have a fever)
- Sore throat
- Stuffy or runny nose
- Muscle or body aches
- Fatigue or tiredness
- Vomiting and diarrhea (more common in children than adults)
Who should get the flu vaccine?
While everyone should get a flu vaccine this season, it is especially important for some people to get vaccinated. Most of us who get the flu generally have a mild illness and recover in less than 2 weeks. Other people can develop flu-related complications such as pneumonia, bronchitis, and sinus and/or ear infections that might require hospitalization. The Center for Disease Control (CDC) recommends that everyone older than 6 months receive the flu vaccine. It is especially important to get the vaccine if you live or care for someone who is at high risk of complications from the flu. Here is more information on who should get the flu vaccine.
Should I get the flu shot or the nasal spray flu vaccine?
The traditional shot contains inactivated or killed virus and is given “intramuscular” or in the muscle. The nasal-spray flu vaccine, a mist sprayed in the nose, is made with live, weakened flu viruses (sometimes called LAIV for “live attenuated influenza vaccine”) and is an option for healthy people aged 2 to 49 years who are not pregnant. It is important to know that the viruses in this vaccine do not cause the flu.If you are a health care worker and care for people with severely weakened immune systems who require a protected hospital environment, it is recommended that you get the flu shot.
There are several vaccine options for the 2013 to 2014 flu season. These options include a “trivalent” vaccine (2 influenza A viruses and 1 influenza B virus) and a “quadrivalent” vaccine (2 influenza A and 2 influenza B viruses). Some of the vaccines are age dependent. The CDC does not recommend 1 flu vaccine over the other. Your health care provider can recommend the best option for you and your loved ones.
When should I get vaccinated?
It depends on when the flu vaccine is available, which is hopefully before the influenza begins to spread in your community. Most places currently have flu vaccines and will continue to have them throughout the flu season. It is important to note that the flu season can begin as early as October, it peaks in January/ February or even later, and it can last as late as May. Remember that it takes about 2 weeks after vaccination for your body to protect you against flu virus infection. If you are sick with a fever, it is best to wait until your fever is gone before getting the vaccine. If you are not sure if or when to get your flu vaccine, talk with your health care provider.
Are there any side effects from getting the flu vaccine?
Side effects vary by person and depend on whether you received the shot or the nasal spray vaccine. For the most part, side effects are mild and short lasting. With the shot, you might feel sore, have redness or swelling where the vaccine was given, and/or experience a low-grade fever and aches. Adults and children receiving the nasal spray vaccine have reported runny nose, wheezing, head and muscle aches, cough, sore throat, and vomiting. More information about the safety of flu vaccine is available on the CDC website.
In addition to getting your flu vaccine, practice the following good, healthy habits:
- Cover your cough/sneeze
- Refrain from touching your eyes, nose, and mouth
- Wash your hands often with soap and water or use alcohol-based hand sanitizer
- Avoid close contact with sick people
- Stay at home and keep your distance from other people when you are sick
- Clean/disinfect frequently touched surfaces at home, work, and school (eg, phones, keyboards, door handles, shopping carts) especially when you or someone else is sick
- Get plenty of sleep, eat well, drink plenty of fluids, remain physically active, and manage your stress
Always remember that the single best way to protect against the flu is to get vaccinated each year. Make it a family affair or take a friend with you.
Don’t wait. Vaccinate!
For some interesting reading, check out this article on the great pandemic influenza of 1918