Influenza or 'flu' is a highly infectious disease that causes unpleasant symptoms, including fever, aches, sore throat, fatigue and nausea. Although common, in very rare cases it can lead to hospitalisation. If you have MS, catching the flu can make your MS symptoms worse. You may notice this particularly if you find that your MS symptoms get worse in the heat.
NICE guidelines recommend that a flu jab is routinely offered free to people in the UK who are at at risk of severe health complications following influenza infection. These include elderly people, young children, pregnant women and people with some long-term health conditions, as well as healthy people who are carers or health care workers.
The flu jab consists of three or four carefully selected strains of influenza that are thought to be the most likely causes of disease in the upcoming flu season (winter in the UK). Inactive versions of those strains are injected into a muscle, usually shortly before the start of the flu season.
There are several different vaccines, intended for different groups of people. Young children are normally given the immunisation via a nasal spray at school. Adults over 65 may be offered a different injectable vaccine to that offered to younger adults.
Your body then makes antibodies against those strains of flu, so that if you are exposed to them at a later date, you will be able to fight off the infection quickly.
Multiple sclerosis is one of the long-term health conditions that are covered by the NICE guidelines, although you and your GP should take into account your individual clinical needs, including any other health conditions you have. The guidelines state that people with MS should be offered immunisation against influenza as flu infections may be associated with worsening of symptoms or could trigger a relapse.
The Department of Health's guidelines also currently state that the flu vaccine should also be offered to all who are in receipt of carer's allowance, or are the main carer for a person whose health or welfare may be at risk if the carer falls ill. In Scotland, Immunisation Scotland encourage people with MS to get the flu jab.
If you have MS, and feel that you are getting the symptoms of flu, or have been in contact with someone with flu, NHS Choices would advise you to talk to your GP. There are antiviral drugs available that can reduce the effects and duration of an episode of flu, but these are most effective when taken as soon after infection as possible.
The flu jab is free for all adults and children with multiple sclerosis, as well as their main carers, if applicable. You can book one with your GP, even if they do not contact you first.
A study reviewing all of the research into flu vaccination and MS found that vaccination was effective in people with MS and offered them protection from flu infection. Although disease modifying drugs affect the immune system, most did not stop the vaccination from being protective against flu infection.
Some research suggests that you might get less protection from the flu vaccine if you're on certain DMDs, however further studies need to be carried out to confirm this.
Being vaccinated against flu does not change your chances of developing MS or of having a relapse if you already have MS.
Having the flu jab does not guarantee that you will not get flu that season. If a different strain of influenza to the ones in your flu jab appears in your community, you will not have complete protection against it.
For people with MS, the side effects of the flu jab are the same as for any other person who recieves it. Some people who have the flu jab experience soreness at the injection site, or the symptoms of a cold, such as a headache, runny nose or sore throat. These generally clear up quickly and can be treated at home.
A study of 49 people with MS reported that five experienced fever or flu-like symptoms after vaccination. No-one reported any new neurological symptoms or had complications or needed hospitalisation.