Getting an influenza vaccine is the best way to prevent the flu and its complications. The Centers for Disease Control and Prevention (CDC) recommends annual flu vaccination for everyone, age six months or older.

This year's annual flu vaccine will offer protection against four of the influenza viruses expected to be in circulation this flu season.

What can be expected after the vaccine?

The flu vaccine does not increase your risk of Covid-19. Patients might develop flu-like symptoms for a variety of reasons, including:

• Reaction to the vaccine: Some people experience muscle aches and a fever for a day or two after receiving a flu vaccine. This may be a side effect of your body's production of protective antibodies
• The two-week window: It takes about two weeks for the flu vaccine to take full effect. If a patient is exposed to the influenza virus shortly before or during that time, they might catch the flu virus
• Mismatched flu viruses: In some years, the influenza viruses used for the vaccine don't match the viruses circulating during the flu season. If this occurs, the flu vaccine will be less effective, but may still offer some protection
• Other illnesses: Many other illnesses, such as the common cold, also produce flu-like symptoms. So, patients might think they have the flu when they don't.

What kind of protection does the flu vaccine offer?

The flu vaccine is generally more effective among people under 65 years old. Some older people and people with certain medical conditions may develop less immunity after receiving a flu shot.

Reviews of past studies have found that the flu vaccine is about 50% to 60% effective for healthy adults who are between 18 and 64 years old. The vaccine may sometimes be less effective.

Even when the vaccine doesn't completely prevent the flu, it may lessen the severity of illness, and reduce the risk of serious complications and serious illness requiring hospitalisation.

It is especially important to get the flu vaccine because the flu and Covid-19 cause similar symptoms. Flu vaccination could reduce symptoms that might be confused with those caused by Covid-19. Preventing the flu and reducing the severity of flu illness and hospitalisations could also decreases the number of people needing to be hospitalised.

It is possible to get a Covid-19 vaccine at the same time the flu vaccine.

Source: Mayo Clinic