Flu Vaccination FAQs

Flu Shot Questions & Answers

Mercy offers comprehensive vaccination and immunization services, including seasonal flu shots. Always consult with your Mercy primary care provider regarding your individual health circumstances. Learn the answers to several frequently asked questions we receive about flu shots.

In the winter, we are inside a lot more, giving us more opportunities to pass illnesses to one another. Also, cold air irritates the mucus membranes in the respiratory tract, which makes them more susceptible to invasion by viruses and other respiratory pathogens. This decreases the body’s natural defenses to fight infections. 

What sets the flu apart from a cold is a high fever, around 102 degrees, achiness and overall illness. Vomiting and diarrhea are also not present in the common cold but can be symptoms of the flu.

Children up to 8 years old require two doses of the flu vaccine given about one month apart, but only the first season they are vaccinated. After that, they need only one flu vaccine dose per year.

The most common side effects of the flu shot are:


  • Low-grade fever
  • Soreness at the injection site (generally your arm)
  • Possible redness or swelling

Yes, flu vaccines are only effective for one season, therefore getting the flu shot in previous years does not protect you from getting the flu in future years. Flu viruses change often and require a new vaccine.

The level of prevention the flu shot provides varies each year. If you still end up getting the flu, the vaccine will help you by minimizing symptoms of the flu, leading to faster recovery.


In addition to receiving a flu shot, remember to follow these preventive measures to protect against the flu:

  • Wash your hands often
  • Sneeze and cough into your elbow
  • Keep your stress level down
  • Get plenty of sleep
  • Make healthy food choices
  • Exercise
  • Limit your exposure to people who are sick

You can get the flu anytime in the year, although we see more cases of the flu between October and as late as April or May. Since there are typically multiple peaks in the flu season, we recommend everyone get a flu shot, especially those at high risks, such as children and the elderly.