Flu Myths & Facts

Although the flu can cause some symptoms which are similar to a cold, it’s a far more serious disease than a cold and you’re likely to feel much worse for longer. In some people, flu develops into more severe illnesses such as pneumonia. In the UK, the number of deaths estimated to be due to seasonal flu varies each year – it has been as high as 10,000 and has reached more than 20,000 in flu epidemic years.¹

It is true that the elderly or very ill are most susceptible to becoming very unwell if they catch flu.  However, it is possible for anyone to suffer from flu and be very ill, although the risks to those who are otherwise fit and well are much lower.

One in three people infected with the flu virus don’t show any symptoms, but they can still spread flu to other people.²

Anyone can suffer severe flu infection, including otherwise healthy people. Around one‐third of school‐age children and up to one in seven adults get infected by flu viruses each season³. The flu vaccine reduces the number of cases of flu in healthy adults by up to 80%.⁴ Anyone can get the flu vaccine. And it’s free for some people specifically recommended to have it by the Department of Health.

The flu vaccine can’t give you flu. The vaccine is made of incomplete parts of the ‘inactivated’ (dead) flu viruses, which means they can’t reproduce in your body or give you the flu. The vaccine may take 2-3 weeks to produce antibodies, so you could catch flu before it starts to work.⁵ There are also other conditions that can cause symptoms similar to flu that the vaccine will not prevent.

It normally takes up to 2-3 weeks after your vaccination for the protection to kick in.⁵ During this time, while the body is building up its immunity, you can still be infected with the flu virus and become ill, which doesn't mean the vaccine doesn’t work - just that it didn’t have enough time to do so.

The potential risks of flu vaccination are small compared to the proven benefits seen in more than 60 years of experience with flu vaccination, where hundreds of millions of people have been vaccinated worldwide. That’s why health authorities around the world recommend flu vaccination. The most commonly seen side effects after flu vaccination are headache, sweating, pain in muscles and joints, fever, tiredness and shivering. Skin redness, swelling, pain and bruising around the injection site are also common.⁵ These symptoms are usually mild and disappear within 1-2 days without treatment.⁵

Immunity from past flu infections is unlikely to be adequate against new circulating flu viruses because flu viruses evolve and change over time. Also, flu vaccination provides protection for 6 to 12 months, which means that you are unlikely to be protected by a flu vaccination received more than a year ago.⁵ That’s why the composition of flu vaccines changes regularly and also why flu vaccination needs to be renewed each year.

Late protection is better than no protection. In the UK, seasonal flu epidemics typically occur within an 8-10 week period during the winter.¹ Although the best time to get vaccinated is usually between September and November, getting the vaccine later can still be beneficial.

Antibiotics, such as penicillin, are designed to kill bacteria and do not work against viruses including flu viruses.  Antibiotics cannot replace vaccination.
 

There are no pig‐ or pork‐based products or processes used in the manufacture of the seasonal flu vaccine. The myth arose because of the so‐called ‘swine flu’ pandemic in 2009.

Antiviral medications, if taken within 48 hours of onset of flu symptoms, may help reduce the duration of flu symptoms by 1 or 2 days.⁶ Antiviral medications cannot replace vaccination.