Can the flu vaccine give you the flu?

We’ve all heard a friend or family member say ‘I had the flu vaccine and it gave me the flu’. But is it actually possible to get the flu from the vaccine? Can the vaccine give you the very thing it is designed to protect you from?

In order to get to the bottom of this lets first find out – what exactly is the flu?

The flu is a nasty viral infection of the upper respiratory tract caused by a seasonal virus called influenza. It has two main strains – A and B. Each year the strains mutate and are named things like ‘B/Brisbane’ or ‘A/California’ based on the strain and where they were isolated. If you are unlucky enough to catch one of these strains you are likely in for a horrible time with fever, severe muscle aches, fatigue, headache, sore throat or cough.

So why do we vaccinate against the flu?

The main reason we vaccinate is to prevent the complications of the flu. These can include annoyances such as sinusitis or an ear infection, right through to life threatening conditions such as pneumonia and multi organ failure!

So can the vaccine give you the flu?

The short answer is no. The influenza vaccine contains a particle designed to look like the flu virus to your immune system but not the actual virus. Your immune system will then create antibodies which will protect you if you are exposed to the
influenza virus. A consequence of this process is that you will probably have a sore arm at the injection site and in rare cases you may develop a low grade fever, muscle aches and a headache. It is this rare reaction to the flu vaccine which makes people think that they have caught the flu from the vaccine, in reality it is just your immune system building antibodies!

Are you eligible for a free flu vaccine?

If you are over 65 years old, pregnant or have a medical condition which predisposes you to severe influenza (i.e severe asthma, heart disease, diabetes) then you qualify for a free influenza vaccine in NSW.

What should I do if I think I have the flu?

If you have a fever, muscle aches and a cough try and get in to see your GP within 48 hours because we can start antiviral medications which might shorten the duration of the illness. We can also perform a nasal swab to check if you have the flu or the common cold. Unfortunately the symptoms of a cold can often be very similar to those of the flu. Usually with the flu you are much more sick and require a couple of days in bed.

If you would like to book in for a flu vaccine through our practice please call 9908 2233 or book online

Author: Dr Robert Mathews