The Flu vaccine and ITP.

Please note that this general advice on the influenza vaccine has been written by one of the Association's medical advisors, Professor Adrian Newland CBE,  but it does not replace any advice given to you by your consultant or GP who knows you and your ITP.

The influenza vaccine has been linked to the development of ITP in a small number of adults and may cause a temporary dip in platelet counts in children or adults receiving the vaccine. However, the risks are higher for children (or adults) who are unvaccinated and develop influenza.

There has been significant disruption created in the health service by Covid-19 this year and as the service strives to clear the backlog of patients needing NHS assessment and treatment, it must also plan for the winter ahead. Many experts have predicted the possibility of a resurgence of the Covid-19, either locally or more generally, and there is also the possibility of a flu epidemic, which we frequently see in the autumn. This poses a serious risk to health in the UK.

These new pressures are in addition to the challenge winter usually presents to the NHS, when other infectious diseases are more common and conditions such as asthma, heart attack, chronic obstructive pulmonary disease and stroke tend to worsen.

Flu vaccination is available and should be considered in addition to the other important steps that we are taking to minimise the of Covid-19.  The advice on how to minimise transmission of Covid-19 in the community, will also help minimise the risks of flu as well. The health service is also working to provide Covid-19 and Covid-19-free zones, and ensuring that there is adequate PPE, testing and system-wide infection-control measures to minimise transmission in hospitals and care homes while also working to provide healthcare for the general population.

As the symptoms of Covid-19 and Flu can be very similar guarding against the worst effects of flu with a concerted effort to get people at risk (including health and care workers) safely vaccinated in the late summer and early autumn will be a very important step.

Flu is an unpredictable virus that can be unpleasant, but if you are otherwise healthy it will usually clear up on its own in about a week. It can cause severe illness and even death among vulnerable groups, including older people, pregnant women and people with an underlying health condition. Certain people are more likely to develop potentially serious complications of flu, such as bronchitis and pneumonia.

The groups in whom the flu vaccine is recommended include:

• are 65 years old or over
• are pregnant
• have certain medical conditions that increase your susceptibility to infection (this is the same list that the Association put out for the Covid-19 risk)
• are living in a long-stay residential care home or another long-stay care facility
• receive a carer's allowance, or if you are the main carer for an elderly or disabled person whose welfare may be at risk if you fall ill
• live with someone who is at high risk of coronavirus (on the NHS shielded patient list) or you expect to be with them on most days over winter

It is likely that the flu vaccine will be extended to all 50-64-year-olds and we are expecting more information in the autumn.  However, if you are aged 50-64 in an at-risk group, you should not delay having your flu vaccine.

The flu vaccine mutates its genetic make-up on a regular basis so that a previous infection may not protect from infection later. Each year the vaccines are made to cover the flu virus strains that have become prominent over the previous months. In general the vaccines are effective in up to about two-thirds of cases, when the vaccine has been matched to the circulating viruses. There is also evidence that even if the vaccine does not fully protect from getting an infection that the impact and complications are lessened by having had the vaccination. There are substantial public health and personal benefits from being vaccinated.

There are many myths regarding the flu vaccine. Two of the main ones are:

The flu vaccine can give me the flu.  Incorrect: The injected flu vaccine contains an inactivated virus that cannot give you influenza. If you feel achy or slightly feverish, it is a normal reaction of the immune system to the vaccine, and generally lasts only a day or two.

 The flu vaccine can cause severe side effects. Incorrect: The flu vaccine is proven to be safe. Severe side effects are extremely rare. One in a million people may get Guillain-Barré Syndrome (GBS), which cause muscle weakness and paralysis. 

The vaccine has been linked to the development of ITP in a small number of adults and may cause a dip in platelet counts in children or adults receiving the vaccine. These are usually transient effects. However, the risks are higher for children (or adults) who are unvaccinated and develop influenza.

Two types of influenza vaccine are widely available: inactivated influenza vaccines and live attenuated influenza vaccines. Traditionally, influenza vaccines (both IIV and LAIV) have been produced to protect against 3 different seasonal influenza viruses (also called trivalent vaccines) but quadrivalent vaccines (against 4 types are also being produced). These are generally given as an injection into the arm. There is also a live attenuated nasal spray influenza vaccine available, for children and those who want to avoid an injection.  There is no preference expressed for any one vaccine over another, all are equally effective. If you have questions about which vaccine is best for you, talk to your doctor or other health care professional. However, note the issues relating to live vaccines in the following paragraph.

Specifically in ITP for the newly diagnosed patient (within 3 months of diagnosis), who is not on treatment flu vaccine need not be given unless there are any of the risk factors previously mentioned.  In the persistent or chronic ITP the flu vaccine should be considered, particularly in the patient who has required, or is on, treatment and in those who have had a splenectomy. The live vaccine should not be given to those who are on, or have recently received steroids or immune suppressive drugs, or rituximab in the past 12 months. This should be discussed with your doctor or the healthcare professional administering the vaccine.

There are on average 10,000 deaths each year in the UK from flu, although in 2017-18 it was more than double that.  Many of these were in at-risk individuals so to reduce spread and the incidence of infection, vaccination should be considered by all people over the age of 6 months every year.

Professor Adrian Newland

August 2020