Myths about seasonal flu vaccine
It’s important to be vaccinated against seasonal flu. Below are some of the myths floating around about flu vaccines, and the facts behind them.

Myth: Getting a flu shot will make me sick.
This is a common misconception, but it’s simply not true. There are several reasons people think the flu vaccine makes them sick:

1. Timing: People get the flu vaccine during flu season. It takes up to 10 days after you're vaccinated before you are protected from influenza. During this time, you could be exposed to someone who has the flu. Exposure to an infected person can get you sick in about two days, before your vaccination has taken effect.

2. After-effects: Influenza vaccine can cause mild flu symptoms for up to two days after you’ve had the vaccination. Some people think this means they’ve caught the flu, but the actual flu causes much more severe symptoms than the vaccine, and lasts much longer.

3. Different strains: Flu season runs from September to May in Oregon. Several strains of the virus circulate each year. Some years the vaccine is not perfectly matched to the circulating strains, and people who’ve been vaccinated get a milder strain of flu.

4. Other illnesses: Influenza is often blamed for illnesses caused by other viruses circulating at the same time. There are hundreds of other flu-like illnesses that can't be prevented by vaccination. Some people become ill with one of these diseases and think they have the flu.

5. Some people won’t be protected even with the flu vaccination. In rare cases, things like a reduced immune system, improper vaccination or mishandled vaccine can prevent vaccination from ensuring immunity. This is why it's critical that everyone be vaccinated, to prevent the spread of influenza to unprotected people.

Myth: I never get the flu.
Not everyone gets influenza each year, but some people may have it and be contagious without knowing it.

Other facts:

• About 5% to 20% of the population get influenza each year. 
• Many infected people never develop symptoms, but they’re still contagious. Young, healthy people are especially likely to have influenza infections without feeling ill. 
• Getting vaccinated is a good idea not only because it lowers your chances of getting influenza, but also to help protect others in your community. When you get vaccinated, you help to reduce the spread of the virus and to protect those with low immunity from coming into contact with it.

Myth: It’s better to get influenza "naturally."
1. Influenza vaccine is effective at preventing influenza and reducing death and illness from the flu and its complications. Even if you are exposed to strains of influenza not included in the immunization, getting a flu vaccine will reduce your symptoms.

2. Influenza can cause many complications beyond respiratory illness. Seasonal flu often causes secondary problems such as sinus infections, ear infections, bronchitis and pneumonia. Influenza can also affect those with diabetes, both by interfering with their personal disease management and by causing changes in the insulin-blood sugar cycle.

3. Influenza disease can last for up to two weeks. It causes many missed days at work and school, and can cut vacations short. People are especially at risk for catching influenza during times of high stress and periods of poor sleep. 

Myth: Influenza vaccine contains mercury and causes autism.
Flu vaccine does not cause autism. There are long-standing myths about vaccine components and autism. This myth is fueled by misunderstandings and poorly designed studies that have received a great deal of public attention. Here are some clarifications: 

1. Name confusion: Thimerasol is used as a preservative in some influenza vaccinations. It is metabolized by the body as ethylmercury and is discharged in about four days. In contrast, methylmercury (quicksilver) is retained in the body indefinitely and is expressed in breastmilk. Methylmercury exists in our environment (mostly due to coal-burning electricity plants) and is known to cause many symptoms of heavy-metal poisoning.

2. Autism is not known to be caused by mercury (of any type). There have been several large, accidental contaminations of bread supplies with methylmercury, causing many thousands of toxic mercury exposures. Although symptoms of heavy-metal poisonings were noticed, the autism rates of those populations did not increase.

3. Only multi-dose vials of influenza contain Thimerasol because single-dose vaccinations do not require preservatives. If you have concerns about preservatives in the influenza vaccine, you may ask your provider if a preservative-free vaccine is available.

4. Thimerasol was removed from most vaccines in 1999 as a response to public concern. Autism rates in children do not appear to have been reduced by doing so.

Myth: I caught the “24-hour flu” or the “stomach flu.”
We've all heard this one. This myth is based on a lack of knowledge about influenza and its symptoms. 

1. The common symptoms of influenza can vary, but often include up to 10 days of: sneezing, coughing, runny nose, congestion, fever over 101 degrees Fahrenheit, muscle aches, and headache.

2. People can have all these symptoms or a mixture of them; some people have no symptoms at all and no idea they are infected.

3. Stomach ailments and overnight sicknesses are not typical of seasonal influenza. These symptoms are probably caused by exposure to a non-influenza virus. 

For more about myths and the flu, check out the US Health Department’s list of flu myths.