Sorting the facts from the fiction about flu vaccinations

A consultant in medical virology from University College London spoke to us about the upcoming flu season and debunked some common misconceptions about flu vaccinations.
Woman in a facemask preparing for a vaccination

Busting Common Flu Myths

1. 'I had the flu, so I don’t need the vaccination'

The flu virus mutates and there’s more than one type. You can also catch more than one strain of flu in the same season. Currently people need a flu vaccination annually but there is research into a universal vaccination.

2. 'It doesn’t work'

The effect of the vaccine may depend on one's own immunity and the effectiveness of the match of virus and vaccine. (Each year the World Health Organisation works out which flu strains it is most sensible to vaccinate against for the following season)

  • In 2016/17 – it prevented around 67% of hospital admissions and was very effective
  • In 2017/18 – it was not such a good match but still reduced hospital admissions by 34%

3. 'I’m allergic to eggs so I can’t have the vaccine'

Most flu vaccines are grown on eggs, however, the amount of egg contained in a vaccine is very small. Unless you’ve had a serious anaphylactic reaction to eating eggs or to a previous flu jab it should be safe. If you’re worried you can speak to your GP about having the vaccine in a controlled environment.

4. 'The flu vaccination gives you flu/ makes you sick'

Neither type of the vaccination can give you the flu, even in the live vaccine the virus cannot mutate back to become strong again. However, it takes 10-14 days for the protection from the vaccine to start, so you could catch the flu before you’re protected.

5. 'The vaccination has toxic ingredients'

The vaccination does not contain mercury. It does contain ethylmercury but this is safe and it’s a very small amount. There is more mercury in a tuna sandwich than the flu vaccine. The ingredients are actually used in shampoos and even ready meals.

6. 'The flu vaccination has terrible side effects/ is not safe to use'

The vaccination was created in the 1930s so is not a new vaccination. It has been trialled and tested and is safe to use. There are normal side effects after a vaccination such as pain at the site of injection, headaches and muscle aches. Whoever gives you the vaccine has a responsibility to report any unusual reactions back to the monitoring body.

7. 'Having the flu vaccination will make you more likely to catch Covid-19'

There is no evidence to support this. You can be infected with Covid-19 and flu at the same time which is why we are suggesting people have the flu vaccine this year, so people don’t get twice as sick. While there are Covid-19 vaccines being tested at the moment, we don’t know when or whether these will be successful and ready for use.

More information about the flu and flu vaccinations

  • This information was shared at the Flu Vaccinations and Covid-19 event we hosted online on 16 September. Read the meeting notes to find out what else we learned.
  • The North Central London Clinical Commissioning Group website also has a lot of useful information, including videos and resources in other community languages.

Find out more

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