Flu outbreak

Seasonal Influenza: What you need to know

Seasonal Influenza: Flu Basics

Influenza (aka, the flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. Serious outcomes of flu infection can result in hospitalization (on average, about 200,000 flu-related hospitalizations annually in the US) or death (between 3,000 - 49,000 annual US deaths result from seasonal influenza). Some people, such as older people, young children, and people with certain health conditions, are at high risk for serious flu complications. The best way to prevent the flu is by getting vaccinated each year.

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Tips to prevent the flu and other colds during the winter

  • Get your flu shot - See your primary care provider or visit the Student Health Center.
  • Wash your hands - Consistent hand washing is the most effective way to prevent the spread of illness. Wash with soap and warm water for at least 20 seconds. Alternatively, use an alcohol-based hand sanitizer (make sure it is at least 60% alcohol).
  • Cover your cough - When you sneeze or cough, use the crook of your elbow (not your hands!) or a tissue to cover your mouth. Throw   the tissue in the trash!
  • Avoid touching your mouth, eyes, or nose! Germs spread this way.
  • Stay home if you are sick- If you don’t feel well, try to avoid going out in public and limit close interactions with others.
  • If you are sick, consider cleaning your linens regularly with hot water
  • Rest- Make sure to get plenty of rest both when you are sick and when you aren’t! Sleep helps the body to prevent illness and to heal   more quickly.
  • Hydrate- Drink lots of water or other fluids to prevent dehydration! It is easy to become dehydrated, especially when you are sick. 

You might ask: "Get the vaccine? Are you serious?"

Contrary to some beliefs, the influenza vaccine CANNOT give you the flu - period. Further, no evidence-based research exists illustrating a connection between vaccines and autism (NPR reference1; NPR reference 2).

  • The Flu Shot:
    • The vaccine is made with flu vaccine viruses that have been 'inactivated' and are therefore not infectious. 
  • The Nasal Spray:
    • The viruses contained in the nasal spray flu vaccine are attenuated (i.e., weakened), which means they cannot cause flu illness. These weakened viruses are also cold-adapted, meaning they are designed to only cause mild infection at the cooler temperatures found within the nose. These viruses cannot infect the lungs or other areas of the body where warmer temperatures exist. The nasal spray is well tolerated and the most commonly reported side effects are mild and include runny nose, nasal congestion and cough.

You might be saying: "OK, so you tell me the vaccine doesn't cause the flu. But, what about people who get a seasonal flu vaccine and still get sick with flu-like symptoms? My friend told me he got the flu immediately after getting the shot last year." 

First and foremost, you do not get sick immediately after exposure to the virus. See "The Flu is Contagious" below for more information.

There are several reasons why someone might get a flu-like illness, even after they have been vaccinated against flu.

  1. Remember, the flu vaccine only protects against influenza viruses - not other viruses. One reason is that some people can become ill from other respiratory viruses besides flu such as rhinoviruses, which are associated with the common cold, cause symptoms similar to flu, and also spread and cause illness during the flu season. 
  2. Once you are vaccinated, the flu vaccine takes about 2 weeks to provide you with the optimal level of protection as it was designed. It is possible to be exposed to influenza viruses (which obviously cause the flu) shortly before getting vaccinated or during this two-week period after vaccination that it takes the body to develop immune protection. This exposure may result in a person becoming ill with flu before protection from the vaccine takes effect. Think about it - many people get the flu shot at the clinic or pharmacy during flu season. Where do sick individuals go for medical care or pharmaceuticals? Exactly. So it is important to get vaccinated early AND use common sense, good hygiene to ensure you are protected.
  3. The seasonal vaccine is designed to protect us from the influenza strains expected to circulate in our hemisphere based on several scientific reasoning - one of which is identifying the strains circulating in the opposite hemisphere during their cold, wintry months when flu is prevalent. Some people may experience flu-like symptoms despite getting vaccinated because they may have been exposed to a flu virus that is very different from the viruses the vaccine is designed to protect against. The ability of a flu vaccine to protect a person depends largely on the similarity or “match” between the viruses selected to make the vaccine and those spreading and causing illness. There are many different flu viruses that spread and cause illness among people. Right now, each vaccine contains protection against 3 strains of influenza virus (aka, trivalent) most likely to cause illness for that season. Although in limited supply, you could possibly receive the newer vaccine containing protection against 4 different strains (a newer FDA-approved quadrivalent vaccine).
  4. The final explanation for experiencing flu-like symptoms after vaccination is that unfortunately, the flu vaccine doesn't always provide adequate protection against the flu. This is more likely to occur among people that have weakened immune systems or people age 65 and older.

Signs and symptoms of flu

People who have the flu often feel some or all of these signs and symptoms:

  •     Fever* or feeling feverish/chills (*It’s important to note that not everyone with flu will have a fever.)
  •     Cough
  •     Sore throat
  •     Runny or stuffy nose
  •     Muscle or body aches
  •     Headaches
  •     Fatigue (very tired)
  •     Some people may have vomiting and diarrhea, though this is more common in children than adults.
    • The public's popular term "stomach flu" is not Influenza at all. Influenza is a respiratory disease NOT a stomach or intestinal disease. Causes of the popular term "stomach flu" could be (among others) Norovirus or Adenovirus.

How flu spreads

Most experts believe that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. These droplets typically travel up to 6 feet in the air. A person might also get flu by touching a surface or object that has flu virus on it and then touching their own mouth, eyes or possibly their nose.

The Flu Is Contagious

Most healthy adults may be able to infect other people beginning 1 day BEFORE symptoms develop and up to 5 to 7 days (maybe even 10 days) after becoming sick. Children may pass the virus for longer than 7 days. Symptoms start 1 to 4 days after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Some people can be infected with the flu virus but have no symptoms. During this time, those persons may still spread the virus to others.

Do I really need a flu vaccine every year?

Yes. CDC recommends a yearly flu vaccine for just about everyone 6 months and older, even when the viruses the vaccine protects against have not changed from the previous season. The reason for this is that a person's immune protection from vaccination declines over time, so an annual vaccination is needed to get the “optimal” or best protection against the flu.

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