By Dr Charles Shepherd, Hon. Medical Adviser, ME Association.
Seasonal flu (also known as influenza) is a highly infectious illness caused by several types of flu virus.
It spreads rapidly through small infected droplets that are coughed or sneezed into the air by an infected person. Even people with mild or no symptoms can infect other people.
As there is no simple answer as to whether you should have a flu vaccine if you have ME/CFS, we want to give you all the information we can to help you make an informed choice. You and your doctor can then decide if you ought to have this protection.
This information is now available as a leaflet that can be downloaded free – for a limited period – from our online shop or ordered from head office: 01280 818964 between 9.30am and 3.00pm, Monday-Friday.
It weighs up the pros and cons of flu vaccination for people with ME/CFS, and contains updated information about the strains of flu that the latest vaccination is seeking to protect people against.
The science behind flu viruses and flu vaccines
There are three types of influenza viruses:
- Type A viruses cause outbreaks in most years
- Type B viruses tend to cause less severe disease and smaller outbreaks, often in children
- Type C viruses cause a minor respiratory illness.
Type A viruses are sub-divided by the type of antigens (immune system markers) found on the surface of the virus – haemagglutinin (H) and neuraminidase (N). There are 18 types of H antigen and 11 types of N antigen identified so far.
These surface antigens constantly change identity by what is called antigenic drift – involving minor changes from season to season – and by antigenic shift, where a major change and new subtype of virus emerges.
Previous exposure to flu or vaccination will not provide protection against these new viral subtypes – so they are constantly monitored by the World Health Organisation to try and make sure that each year's flu vaccine is going to be effective against new and emerging strains of flu virus.
Studies have shown that flu vaccines reduce the risk of catching flu, although protection will not be complete and will vary from person to person. Protection gradually decreases over time and flu strains change over time. So new vaccines are made each year and people at increased risk are encouraged to be vaccinated every year.
The 2017-2018 Flu Vaccine
The flu jab is offered free on the NHS to people in certain at-risk groups. These are mainly people who are at greater risk of developing serious complications if they catch flu.
The list includes people with a number of pre-existing health conditions – including neurological ones, pregnant women, obesity and the over-65s (or people who will be by 31st March 2018).
People who receive a Carer’s Allowance, or are the main carer for a sick or disabled person, are also eligible for a free NHS vaccine.
Most injected flu vaccines for 2017-8 protect against three types of flu virus:
- A/H1N1 – the strain of flu that caused the swine flu pandemic in 2009
- A/H3N2 – a strain of flu that mainly affects the elderly and people with risk factors like a long-term health condition. In 2017/18 the vaccine will contain an A/Hong Kong/4801/2014 H3N2-like virus
- Influenza B – a strain of flu that particularly affects children. In 2017/18 the vaccine will contain B/Brisbane/60/2008-like virus.
The nasal spray flu vaccine and some injected vaccines also offer protection against a fourth B strain of virus, which in 2017/18 is the B/Phuket/3073/2013-like virus. The nasal spray is given to young children and older children with long term health problems that place them at increased risk of complications from catching flu.
Swine flu is the popular name for influenza caused by a relatively new strain of influenza virus A. It was responsible for the flu pandemic in 2009-10. The virus is officially known as influenza virus A/H1N1pdm09.
The best time to have a flu jab is in the autumn – from mid-September onwards through until early November. It takes two to three weeks for the vaccine to become fully effective.
Do people with ME/CFS meet NHS criteria for having free Flu vaccine?
Having a chronic neurological disease is one of the recommended criteria for NHS flu vaccination, and the classification of ME/CFS in WHO ICD10 as a neurological disease is fully recognised by the Department of Health.
The ME Association believes that people with ME/CFS should therefore qualify for a free NHS flu jab if they decide to have one.
Dame Sally Davies, Chief Medical Officer at the Department of Health, has also stated in 2014:
“As you know, the risk of serious illness from flu and consequent hospitalisation and death is higher among those with underlying health conditions such as M.E. We know that people with chronic neurological conditions are approximately 40 times more likely to die if they develop flu than individuals who have no other underlying health conditions.
“The best way for people at risk from flu to protect themselves and their families is to get the flu vaccine. People with clinical risk factors are eligible to receive the seasonal flu vaccine free each winter.”
The key points in favour of vaccination if you have ME/CFS include:
- Flu vaccination should provide a fairly high degree of protection against the strains that are likely to be around this winter
- Overall, the vaccine reduces the chances of catching flu by about two-thirds. However, the level of protection given by the 2014-15 vaccine was disappointingly low at around 34%
- Protection continues for about a year
- Anyone with serious health problems in addition to ME/CFS such as chest (especially asthma or bronchitis), heart, liver or kidney disease, diabetes, a weakened immune system, or who is taking steroid medication, is particularly at risk of developing serious complications from flu
- If you have already had a flu vaccine while suffering from ME/CFS, and not suffered any adverse effects, it is reasonable (but not guaranteed) to assume that you should be OK this time round (although the viral make-up of the vaccine is changed from year to year)
- Serious adverse reactions are very rare with this vaccine although minor transient problems such as malaise, headache and muscle pain do sometimes occur (a full list of potential side-effects is listed below)
The key points of caution if you have ME/CFS include:
There are anecdotal reports of people with ME/CFS suffering a relapse, or even developing ME/CFS, after a flu vaccination.
This could be due to the fact that research into immune system dysfunction in ME/CFS has found evidence of what is called immune system activation – which equates to a persisting and overactive immune response to a triggering infection.
Vaccines are designed to mimic the infection they are designed to protect against and so they also trigger an immune system response.
In a small survey carried out by the ME Association among its members a few years ago, seven out of 21 people had no problems at all, 13 reported an exacerbation of symptoms ranging from mild (3) or moderate (7) through to a severe relapse in three cases. Interestingly, there was one report of a teenager who noticed a slight improvement in symptoms following vaccination.
An ME Association online poll carried out in November 2008 asked how the flu vaccine had affected M.E. symptoms. There were 191 responses:
- 86 (45%) reported no change
- 52 (27%) said they were much worse
- 42 (22%) said they were slightly worse
- 7 (4%) said they were slightly better and,
- 4 (2%) said they were much better after the jab.
It is impossible to predict if someone with ME/CFS is going to experience an adverse reaction to flu vaccine.
Some doctors believe that this may be more likely to occur if you still have on-going flu-like/infection symptoms such as enlarged glands, sore throats, problems with temperature control, etc.
The only published research study into adverse reactions to flu vaccine in people with ME/CFS concluded that people with ME/CFS were no more likely to have a serious adverse reaction than people receiving this vaccine for recommended reasons.
- Reference: Influenza Vaccination: Is it appropriate for Chronic Fatigue Syndrome? American Journal of Respiratory Medicine 2002,1: 3-9.
However, two case reports involving health workers who developed ME/CFS after swine flu vaccination have been reported in the British Medical Journal. Both developed moderate to severe symptoms and were unable to return to work.
- Reference: Should influenza vaccination be mandatory for healthcare workers? BMJ, 2013; 347:f6705.
Contraindications and cautions
The flu vaccine may be contraindicated in people who have had a previous reaction, or are allergic to eggs and poultry – as it contains small amounts of egg and poultry proteins. This is something you need to discuss with your doctor because there are now egg-free vaccines available.
You should also inform your doctor if you are allergic to any of the possible vaccine components and preservatives: eg, formaldehyde, gentamicin sulphate and sodium deoxycholate. One further contra-indication is having an active febrile illness.
Some flu vaccines used to include thimerosal – the controversial mercury-containing preservative. This has now been gradually withdrawn from vaccines following concerns that it could cause neurological problems.
Common and normally transient side-effects include a slight temperature and aching muscles for a couple of days after having the jab and the arm may feel a bit sore. If you do experience a sore arm after vaccination, use a heat pack or warm compress on the area and take a painkiller such as paracetamol or ibuprofen. Serious side-effects are very rare.
Recognised potential side-effects listed in the literature provided to doctors include local redness, swelling, pain, bruising, fever, malaise, shivering, fatigue, headache, sweating, myalgia (muscle pain), arthralgia (joint pain), generalised skin reactions (itching, urticaria}, neuralgia (nerve pain), paraesthesiae (abnormal sensations).
More serious side-effects include convulsions, transient thrombocytopenia (lowered level of platelets in the blood), encephalomyelitis, vasculitis (blood vessel inflammation), neuritis (nerve inflammation) and Guillain Barre syndrome. These complications are much more unusual.
The vaccine does not contain any live virus and cannot therefore cause flu.
The use of a specific adjuvant known as AS03 – an emulsion that was added to stimulate the immune response in a previous vaccine – has been linked to narcolepsy.
Where to have a vaccination
Most people have their flu jab at the GP surgery – where it is free if you have one of the conditions listed above where flu vaccination is recommended by the NHS.
Flu vaccine is also becoming increasingly available for a small charge at High Street pharmacies such as Boots. Boots currently charge £12.99p – they will also provide a free jab to those who are eligible by NHS criteria.
Reducing the risk of catching the flu and passing on the virus
Children are a major source of infection – because flu is essentially a disease of childhood – but keep a safe distance – at least two metres – from anyone who is coughing, sneezing, or may have flu, and avoid crowded public places.
The virus can also be caught be contact with infected surfaces, including hands – so avoiding handshakes and hugging is another sensible precaution during the flu season. Sneezing into your elbow – not the palm of your hand – reduces the risk of spreading the virus.
Research into flu vaccines and ME/CFS
The effect of influenza vaccination on ME/CFS was examined in an Australian pilot study which found that vaccination is accompanied by a degree of immune system dysregulation in ME/CFS patients compared to controls and that the vaccine has the ability to increase cytotoxic activity and pro-inflammatory reactions post vaccination (Brenu et al 2012). However, Prinsen et al (2012) found that humoral and cellular immune responses following influenza vaccination were comparable in ME/CFS patients and healthy controls.
Reference: Brenu EW et al. The effects of influenza vaccination on immune function in patients with chronic fatigue syndrome/myalgic encephalomyelitis. International Journal of Clinical Medicine, 2012, 3, 544 – 551.
Reference: Prinsen H et al. Humoral and cellular immune responses after influenza vaccination in patients with chronic fatigue syndrome. BMC Immunology, 2012, 13, 71.
Further information on Flu vaccination
The NHS Choices webpage gives helpful and more detailed general guidance on all the common queries relating to flu vaccine and how to obtain it.
The Boots flu vaccine webpage provides basic information and allows you to book an appointment at your local store.
ME Association Disclaimer
Medical information provided above is not intended to be a substitute for medical advice or treatment from your doctor. The ME Association recommends that you always consult your doctor or healthcare professional about any specific problem. We also recommend that the medical information provided by The ME Association is, where appropriate, shown to and discussed with your doctor.
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