A slight fever? Aching muscles? These include life-threatening allergic reactions to a previous dose of the flu vaccine or an ingredient in the vaccine.
But the CDC reports that there are several new things this season.
Though the injectable vaccine is preferred, federal health officials have approved the use of a nasal spray flu vaccine this season. Children 6 months to 4 years of age are considered high risk, since their immune system is still developing.
The vaccines contain a variety of other ingredients, ranging from egg proteins to antibiotics to formaldehyde (in trace amounts that won't endanger your health). Vaccines typically come in trivalent (protecting against three viruses - two A-strains and one B-strain) or quadrivalent (protecting against four strains - two A-strains and two B-strains).
For those paying cash, pharmacies generally charge $20 to $45 per shot, but the price can vary based on which drugstore you visit. But these are not flu symptoms. Don't wait, get vaccinated. But not for the reasons you might think.
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"If you haven't gotten a flu shot, it's never too late", she said.
Among the benefits of getting vaccinated for the flu: Getting a vaccine doesn't mean you won't get the flu, but if you do get sick it could be less severe, experts say. These groups are more often under-vaccinated. "I harass the rest of my family to get vaccinations", adding that the vaccine is the best avenue to avoid flu complications. She said it not only protects them against the illness but helps protect those who might not be able to get the vaccine. But officials warn that it's still better to get a flu shot than risk getting the flu without one. The illness is not from the flu vaccine.
How long does a flu shot last?
It's especially important for people 65 and older (50 and older is recommended by the CDC) to get the flu shot, since their ability to fight the virus is lower. It takes up to two weeks for protection to develop after the shot, and there is the rare occasion when a person will become ill during that period of time.
Some of the age ranges for certain vaccines have been lowered and some vaccines were reformulated to better prevent now circulating viruses.