Each fall, you’re hit with tons of messages about receiving your flu shot. But, as a relatively healthy person, YOU surely don’t need one, right? Wrong. Stephen Rinderknecht, DO, UnityPoint Health, explains how the annual flu vaccine keeps you healthy, common reactions to the flu shot and how effective it is in the population.
Should I Get a Flu Shot?
While the total number of deaths from influenza varies, typically, deaths for the entire population amount to 30,000-35,000 each season.
“I always stress that influenza is a serious illness,” Dr. Rinderknecht says. “How well the flu vaccine protects depends on how well the strains in the vaccine match the strains that are circulating in the community.”
The different strains of the flu impact people differently. Dr. Rinderknecht explains how influenza A causes moderate to severe disease and infects both humans and some animals, like birds and pigs. Influenza B generally causes milder disease and is more common in children. Influenza B is more stable, so it doesn’t change as easily and only infects humans.
While he encourages all people over 6-months-old to receive the vaccine, he stresses the importance for high-risk populations, that includes those under 2-years-old, 65-years-old and above and anyone with chronic medical conditions. Dr. Rinderknecht says it’s also a good idea for expectant moms to schedule their vaccines, too.
“Term and near-term newborns receive protective antibodies from their mothers during late pregnancy. Getting a flu shot vaccine during pregnancy not only helps protect the mother, but also the new infant. Infants can’t start their own flu vaccine until six months of age, so this is the best way to protect the most vulnerable and youngest of our patients,” Dr. Rinderknecht says.
How Effective is a Flu Shot?
The effectiveness of each flu vaccine can range from 30 percent to nearly 70 percent. The higher the number, the better matched the vaccine is with the flu strains in circulation. You might ask yourself, if the flu shot isn’t 100 percent accurate, why bother?
“Considering how sick you can become with this virus, even 30 percent protection is a lot better than none. Plus, there is no down side to getting the vaccine, other than possibly spending a few dollars and potentially a slightly sore arm muscle,” Dr. Rinderknecht says.
Even if you get a vaccine and get a strain of the flu that’s not covered, chances are you’ll suffer from less severe symptoms than someone who didn’t receive the vaccine.
What are Common Flu Shot Side Effects?
Flu shot side effects include soreness, redness and swelling at the injection site, according to Dr. Rinderknecht. He says flu shot symptoms are generally mild and last for a day or two.
“Like all other vaccines, the site of administration is determined by age and muscle mass. The only muscles used should be the outside of the thigh or the upper arm (deltoid). The buttock should never be used due to possible nerve damage,” Dr. Rinderknecht says.
Dr. Rinderknecht says cold-like symptoms after the flu shot of fever, chills and muscle aches are reported in less than one percent of those who receive the vaccine. Severe allergic reactions are also extremely rare. Dr. Rinderknecht adds it is impossible to get the flu from the flu vaccine.
“The shot form of the vaccine has particles (antigens) of the virus, but not whole infectious viruses. The vaccine virus has been altered so that is does not cause disease. The flu shot is safe.”
Those over 65 shouldn’t have any additional flu shot reactions. Just like the rest of the population, the main flu shot side effect is tenderness at the site of the injection.
“The problem with vaccines and the older population is the poor immune response to the vaccine. Like other vaccines, it just doesn’t work as well in the more mature population,” Dr. Rinderknecht says.
When Should I Get a Flu Shot?
The flu spreads every year. However, the timing, how long the season lasts and where it hits the hardest is different each season. The flu season can begin as early as October and can last into May.
Dr. Rinderknecht says you should get the flu shot as soon as it becomes available, saying by October, if possible. While early fall is the ideal time to get a shot, it’s never too late. Dr. Rinderknecht says there’s often a late outbreak of a different strain, so getting a flu shot anytime during the season is beneficial. It takes two weeks for the vaccine to provide full protection. There are only about two months during the summer when the flu shot isn’t available.
“All flu vaccines expire on June 30 of each year, so that's the last possible day to vaccinate before the next season’s vaccine is available,” Dr. Rinderknecht says.
The World Health Organization tracks flu changes around the world over time. During our summer season, it is peak flu season in the southern hemisphere. Years when the vaccine is not as effective happen when the flu virus makes an unexpected change before our flu season begins.
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Flu vs. Cold
Influenza and a cold are very different.
“A typical cold starts gradually, mostly with a runny nose, stuffy, slight cough, little or no fever, peaks on day two to four and then gradually improves. A typical case of influenza starts abruptly with high fever, sore throat, cough and severe muscle aches. Patients can often tell me the hour they become ill.
Symptoms persist for several days before gradually improving,” Dr. Rinderknecht says.
What if I Get the Flu?
If you contract the flu, Dr. Rinderknecht says rest and fluids are the two most important tips to remember.
“It takes energy from your body to fight off the flu. If that energy is used to try to keep up normal activities, you have less energy to fight off the infection,” Dr. Rinderknecht says.
Everyone who has the flu should stay home from school and work.
“You are most contagious during the peak of the illness, or the first three days. You continue to shed the virus in respiratory secretions for 7-10 days,” Dr. Rinderknecht says.
Dr. Rinderknecht says patients who contract the flu can use antiviral medication to shorten the course and decrease the severity of the illness. Anyone in the high-risk group who believes they have the flu should make an appointment to see their provider immediately. The most common complication from the flu is bacterial pneumonia.
If you feel you’ve contracted the flu or have any questions about the flu vaccine, contact your UnityPoint Health primary care provider.
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