Dr. Sean Cahill is the medical director of the Loyola Center for Health at Wheaton. He is an associate professor in the departments of adult internal medicine and pediatrics at Loyola University Chicago Stritch School of Medicine. Have a medical question? E-mail askcahillmd@gmail.com

Q: I’m pretty healthy and I still haven’t gotten a flu shot this year. Do you think I should?

A: Influenza is an acute respiratory illness caused by a virus that occurs in outbreaks worldwide, typically in the winter months. The hallmark characteristics of influenza are fevers, headaches, and muscle aches, along with severe cold symptoms. It is transmitted through sneezing, coughing, and even talking by large-particle droplets.

It is best to prevent the transmission of influenza as much as possible since treatment options are very limited. Important measures to prevent the transmission of influenza are handwashing, antiseptic gels, and staying home from school or work when ill. Vaccination is another very important measure to stop the flu.

It has been recommended that everyone this year over the age of 6 months be vaccinated against influenza. So yes, you should still get your flu shot as long as you do not have an egg allergy. Flu season peaks in January and extends all the way to March, so that flu shot will still benefit you.

This year’s vaccine has been very good at preventing the spread of influenza, and very accurate with regard to the types of flu that have been seen so far in the United States. This year’s vaccine contains several strains of influenza including the H1N1 strain that caused a panic last year.

There are many varieties of the influenza vaccine, from intramuscular injections to nasal sprays, from large multidose vials to individual vials that may be more costly. Consult your physician about which types their office stocks and which may be appropriate for you.

Certain groups of patients are considered high risk and should be prioritized with regards to influenza vaccination. These include: asthmatics, diabetics, the immunocompromised (such as those with HIV), patients with chronic liver disease, and pregnant women.

Several patients in my practice report that they have “gotten the flu from the flu shot,” and it is a common perception that the vaccine can make you ill. It activates your immune system after it is administered, and patients often feel a little achy afterward or even spike a slight fever. This is your normal immune response to the vaccine, not the vaccine giving you influenza. In other words, it means the vaccine is doing its job.

If you think you may have the flu, it may be worth a trip to the doctor, although during last year’s H1N1 outbreak we asked patients to stay home to prevent the spread of the illness. Treatments are limited to antivirals that will not make you feel better but may shorten the course of the illness by a day or two if prescribed early in the illness. If you have a fever that persists, a severe cough or shortness of breath, you should be seen by your doctor. A small fraction of patients with influenza develop pneumonia, and antibiotics may benefit those patients.