Four questions about side effects of the flu shot

What do we know about side effects of the flu shot?

For starters, experts call the flu shot one of the safest vaccines we have, but a side effect can always occur. For an expert, it is quite a puzzle to be able to link a reported side effect to the vaccine. Because is that headache now because of the vaccine, or because of that half bottle of wine from last night? That is why it is useful that studies have been done in which the connection between vaccine and side effect can be better established. The results of the research have been incorporated in the package insert of Influvac Tetra, because that’s the name of the flu shot given by the GP this year. The good news: Most side effects are mild and go away within three days. Injection site pain, fatigue and headache occurred in at least 1 in 10 vaccinees. Less common side effects include sweating, muscle aches, joint pain, shivering and a sick feeling. This occurs in at least 1 in 100 people who get this flu shot. Fever is even less common. Good to know, by the way: you are only protected against the flu virus after one week out of two.

Another vaccine has been purchased by general practitioners for children: Vaxigrip Tetra. However, this can also be given to adults, according to the NHG . manual. Given the shortages, GPs can therefore also give these shots to adults. Read more here about this childhood vaccine and its side effects.

When is a side effect dangerous?

The package insert warns of serious allergic reactions, which are rare but require prompt action. ‘Low blood pressure, accelerated shallow breathing, accelerated heart rate and weak pulse, cold, clammy skin, dizziness, which can lead to fainting (shock). Or a swelling most evident in the head and neck area, such as swelling of the face, lips, tongue, throat or other part of the body, which may cause difficulty in swallowing or breathing (angioedema). ).’, according to the package insert. Such a reaction can occur, for example, if you are allergic to chicken protein or certain antibiotics. These people are advised not to take the flu shot.

I have another side effect. Is that possible?

Yes that is possible. In the product information for doctors states that only 768 people aged 18-61 and 765 who were over 61 years of age participated in the study. That’s not many people, when you consider that 3.5 million flu shots are given in the Netherlands alone. The participants were healthy, while now mainly people from risk groups receive the call. So we don’t know everything yet, although the vaccine is broadly similar to flu vaccines from previous years, about which we already have a lot of information. In addition, we have been receiving a new type of flu vaccine for two years now, which works against four flu strains instead of three. Finally, one last reason to take side effects seriously: many people aged 73 to 79 receive a pneumococcal shot (in another arm) in addition to the flu shot. This combination has not yet been investigated. Influvac Tetra’s product information states: ‘It should be taken into account that side effects may be aggravated.’

What can I do?

In any case, report the side effect to your doctor. You can also report to the side effects center Lareb. There you can find figures of previously reported side effects with the flu shot for at least the past 20 years. This therefore contains reports of different flu vaccines mixed up. These figures show, for example, that many people have ‘flu-like’ symptoms after the flu shot, such as coughing or a runny nose. These reports are exchanged between countries so that doctors know more about the side effects and can warn about them.