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This resource provides the background to seasonal influenza immunisation, and includes the definition of influenza, and details of influenza vaccines. It covers up-to-date information on who to vaccinate, which vaccines are available and how to administer them, the contraindications and adverse effects of influenza vaccines, how to manage egg allergy, and what information and advice should be provided to people receiving a vaccine.


On completion of this module you will know:

  • Which at risk groups should be vaccinated
  • Which vaccine to use for whom and how to administer them
  • The contraindications to influenza vaccine
  • Tthe adverse effects of influenza vaccine
  • How to manage people with egg allergy
  • What information and advice to give to people receiving influenza vaccine.


Preparing for the flu season during the COVID-19 outbreak Amy Shirtliff

This resource is provided at an intermediate level by Clarity Informatics. Read the article and answer the self-assessment questions, and reflect on what you have learned.

Complete the resource to obtain a certificate to include in your revalidation portfolio. You should record the time spent on this resource in your CPD log.

Seasonal influenza immunisation

What is influenza?

Influenza is an acute viral infection of the respiratory tract. Influenza types A and B are responsible for most cases of clinical illness in the UK.

In healthy people, seasonal influenza is usually a self-limiting condition, and recovery is typically within 2–7 days.

In older people and those in specific clinical risk groups, seasonal influenza may be more likely to result in serious complications such as pneumonia, meningitis, encephalitis, and death.

Influenza vaccines

The World Health Organization (WHO) makes recommendations each year about the strains to be included in influenza vaccines for the forthcoming winter for the northern and southern hemispheres, based on worldwide monitoring. For more information see the WHO website.

All but one of the influenza vaccines available in the UK are inactivated and do not contain live viruses. Inactivated vaccines are usually administered intramuscularly. Inactivated influenza vaccines are either trivalent, containing two subtypes of influenza A and one B virus, or quadrivalent, with an additional B virus.

One vaccine (Fluenz Tetra) is a quadrivalent attenuated live vaccine administered by nasal spray.

An annual list of the influenza vaccines available in the UK is published ahead of each influenza season in the National flu immunisation programme plan for England, available at

Who should be offered the seasonal influenza immunisation?

Influenza vaccination should be given as soon as possible to provide protection before flu starts to circulate and should ideally be completed by the end of November, but can also take place up until the following 31 March.

Annual seasonal influenza immunisation is recommended for people who are more at risk of the complications of influenza, including:

  • All people aged 65 years and older, and for 2020-21 people aged 50–64 years (subject to vaccine supply).
  • All people aged 6 months to under 65 years in clinical risk groups.

Seasonal influenza immunisation is also recommended in certain healthy people to reduce the risk of transmission to vulnerable groups, including:

  • Children aged 2–10 years on 31 August 2020, and for 2020/21 children of school year 7 age in secondary schools (those aged 11 years on 31 August 2020).
  • People living in long-stay residential and nursing homes or other long-stay care facilities (not including prisons, young offender's institutions, or university halls of residence).
  • Close contacts of immunocompromised people, including carers (people who expect to share living accommodation on most days over the winter).
  • All healthcare and social care workers directly involved in patient care, including students, trainees, and volunteers working with patients. (This should be provided by their employer's occupational health service unless the person falls within one of the clinical risk groups.)
  • People in receipt of a carer's allowance, or those who are the main carer of an elderly or disabled person whose welfare may be at risk if the carer falls ill. This should be considered on an individual basis, at the healthcare professional's discretion.
  • Hajj and Umrah pilgrims: the Ministry of Health for the Kingdom of Saudi Arabia recommends that international pilgrims are immunised against influenza before they enter Saudi Arabia, especially if they are in a clinical risk group. For all other travellers, seasonal influenza vaccination is not available on the NHS.

In addition, for 2020/21, seasonal flu vaccination will also be offered to:

  • Household contacts of those on the NHS Shielded Patient List, specifically, individuals who expect to share living accommodation with a shielded person on most days over the winter and therefore for whom continuing close contact is unavoidable.
  • Health and social care workers employed through Direct Payment (personal budgets) and/or Personal Health Budgets, such as personal assistants, to deliver domiciliary care to patients and service users.

What are the clinical risk groups that should be offered the seasonal influenza immunisation?

Clinical risk groups in people aged 6 months and older include (note this list is not exhaustive):

  • Chronic respiratory disease — chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, interstitial lung fibrosis, pneumoconiosis, and bronchopulmonary dysplasia (BPD); people with asthma that is so severe that it requires continuous or repeated use of inhaled or systemic corticosteroids, or with previous exacerbations requiring hospital admission; children who have previously been admitted to hospital for lower respiratory tract disease.
  • Chronic heart disease — congenital heart disease, hypertension with cardiac complications, chronic heart failure, and people requiring regular medication or follow up for ischaemic heart disease.
  • Chronic kidney disease — chronic kidney disease stage 3, 4, or 5, nephrotic syndrome, and renal transplantation.
  • Chronic liver disease — cirrhosis, biliary atresia, and chronic hepatitis.
  • Chronic neurological disease — stroke and transient ischaemic attack (TIA); co-morbidities that could be exacerbated by influenza, or people who are at risk of serious illness from influenza itself. These may include, for example:
    • cerebral palsy, learning disabilities, Parkinson's disease, multiple sclerosis, motor neurone disease, or hereditary and degenerative diseases of the central nervous system or muscles, or severe neurological disability; conditions where respiratory function may be compromised, such as people with polio syndrome.
  • Diabetes mellitus — type 1 diabetes and type 2 diabetes.
  • Immunosuppression — due to disease or treatment. For example, people:
    • Undergoing chemotherapy or bone marrow transplant.
    • With HIV/AIDS.
    • Taking DMARDs or biologics.
    • Treated with systemic corticosteroids for more than a month at dosages equivalent to prednisolone 20 mg or more daily (any age). Or, for children who weigh less than 20 kg, a dose of 1 mg or more per kg per day. Some immunocompromised people may have a suboptimal immunological response to the seasonal influenza vaccine.
  • Asplenic, or splenic dysfunction — homozygous sickle cell disease and coeliac disease.
  • Pregnant women — at any stage of pregnancy, including women who become pregnant later in the influenza season.

Use clinical judgement to assess whether influenza vaccine should be offered to newly pregnant women, particularly if after the usual immunisation time period, taking into account the level of influenza-like illness in the community, and the fact that the immune response following immunisation takes about 2 weeks to fully develop.

  • Morbid obesity — adults with a body mass index (BMI) of 40 kg per m2 or greater (depending on clinical judgement).

Which vaccines are available?

Click to open larger version

None of the vaccines listed in the table contain thiomersal as an added preservative. Most of the viruses are grown in embryonated hens' eggs and are then chemically inactivated before being further treated and purified.

Quadrivalent vaccines contain two subtypes of influenza A virus and two subtypes of influenza B virus.

In the 2020/21 influenza season in the northern hemisphere, it is recommended that egg-based quadrivalent vaccines include:

  • An A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus.
  • An A/Hong Kong/2671/2019 (H3N2)-like virus.
  • A B/Washington/02/2019 (B/Victoria lineage)-like virus.
  • A B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

In the 2020/21 influenza season in the northern hemisphere, it is recommended that cell- or recombinant-based quadrivalent vaccines include:

  • An A/Hawaii/70/2019 (H1N1)pdm09-like virus.
  • An A/Hong Kong/45/2019 (H3N2)-like virus.
  • A B/Washington/02/2019 (B/Victoria lineage)-like virus.
  • A B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

What vaccine should be used?

In the 2020/21 influenza season, it is recommended that:

  • All people aged 65 years and older should receive the adjuvanted trivalent inactivated vaccine (aTIV).
    • The cell-based quadrivalent influenza vaccine (QIVc) (Flucelvax Tetra) can be offered if aTIV is unavailable.
  • All people aged 18–64 years who are eligible for influenza vaccination, including pregnant women and healthcare workers, should receive a quadrivalent inactivated vaccine (QIVc) or the egg-grown quadrivalent influenza vaccine (QIVe).
  • Children aged 2–17 years in a clinical risk group, or as part of the national influenza immunisation programme, should receive the quadrivalent live attenuated influenza vaccine (LAIV) given as a nasal spray (Fluenz Tetra).
  • Children in clinical risk groups who have never previously received influenza vaccine, and are aged less than 9 years should be offered a second dose of Fluenz Tetra at least 4 weeks later. If Fluenz Tetra is unavailable for this second dose (due to batch expiry) an inactivated influenza vaccine can be given (see product inserts for advice about use in specific age groups).
  • Children aged under 9 years who are contraindicated to LAIV should be offered a QIVe.
  • Children aged 9 years and over who are contraindicated to LAIV should be offered QIVc.

Note: Fluenz Tetra contains a highly-processed form of porcine gelatine that may not be acceptable to some faith groups. Children and young people in a clinical risk group who choose not to have the nasal spray should be offered a QIVe. For 2020/21, children who are not in a clinical risk group may be offered an alternative vaccine (providers will receive notification of a suitable alternative).

For children in clinical risk groups aged from 6 months to less than 2 years, offer a suitable QIVe. Children who have not received influenza vaccine previously should be offered a second dose at least 4 weeks later.

Note: inactivated influenza vaccines can be considered interchangeable for children younger than 9 years of age who require a second dose of influenza vaccine (but see product inserts for advice about use in specific age groups).

What contraindications and cautions are associated with influenza vaccines?

Do not give influenza vaccine to people with a confirmed anaphylactic reaction to:

  • A previous dose of the vaccine.
  • Any component of the vaccine (except ovalbumin).

If there is any uncertainty about the appropriate management of a person with a suspected or confirmed history of anaphylaxis, seek specialist advice from the local immunisation co-ordinator, consultant in communicable disease control, or a consultant paediatrician, to minimise the time period that the person is left unvaccinated.

For people with a suspected or confirmed anaphylactic reaction to one or more excipients, ensure that the vaccine formulation is free of the identified excipients (for example, neomycin or other aminoglycosides). For further information, see the Summary of Product Characteristics for the individual influenza vaccines on the electronic Medicines Compendium website at

Do not give the influenza vaccine to people who are acutely unwell (with a febrile illness or acute infection) — postpone immunisation until they have fully recovered.

Minor illnesses without fever or systemic upset are not valid reasons to postpone immunisation.

Fluenz Tetra nasal spray is contraindicated in children or young people who:

  • Are severely immunocompromised due to an underlying medical condition or treatment, such as leukaemia, lymphoma, and HIV infection not on treatment, an immune deficiency, or if taking high-dose corticosteroids.
  • Have severe asthma or active wheezing.
  • Have a history of severe anaphylaxis to egg which has previously required intensive care management in hospital.
  • Are taking systemic salicylate therapy.
  • Are pregnant or breastfeeding.

Fluenz Tetra nasal spray is not recommended in children or young people:

  • Who have heavy nasal congestion — consider postponing until symptoms have resolved (or using an alternative vaccine by an alternative route).
  • With a history of active wheezing in the previous 72 hours, or who have increased their bronchodilator use in the previous 72 hours — if their condition has not improved after a further 72 hours, offer an alternative inactivated vaccine.
  • Where close contact with a severely immunocompromised person is likely or unavoidable (for example a person with a bone marrow transplant requiring isolation is a household contact) — consider offering an alternative inactivated vaccine.
  • Until 48 hours after stopping treatment with an influenza antiviral agent.

How should a person with egg allergy be managed?

Determine if the person has a true egg allergy — the following are not considered to be true egg allergy:

  • A family history of a reaction to an influenza or any other vaccine.
  • A family history of egg allergy.

For children with a history of severe anaphylaxis to egg that has previously required intensive care management in hospital, arrange referral to a paediatric immunologist or allergy specialist for immunisation in hospital.

Fluenz Tetra nasal spray is contraindicated in anyone who has had a severe allergic reaction (for example to anaphylaxis) to egg or to egg proteins.

For all other children with a history of egg allergy:

Fluenz Tetra can be given to most children with egg allergy in any setting, including primary care.

Egg-allergic children with asthma can receive Fluenz Tetra provided their asthma is well-controlled.

If there are contraindications to Fluenz Tetra, give an inactivated influenza vaccine with a very low ovalbumin content (less than 0.06 micrograms per 0.5 mL dose). For more information on the ovalbumin content of different influenza vaccines, see the Public Health England (PHE) immunisation web pages at

For adults with a history of severe anaphylaxis, which has previously required intensive care management in hospital, arrange referral to an immunologist or allergy specialist for immunisation in hospital.

For adults with less severe egg allergy, give an inactivated influenza vaccine with a very low ovalbumin content (less than 0.06 micrograms per 0.5 ml dose).

People aged 65 years and over with an egg allergy should be given the QIVc Flucelvax Tetra, as the aTIV vaccine contains more than the recommended ovalbumin content for people with egg allergy.

How should influenza vaccine be administered?

Seasonal influenza vaccine should be given annually, ideally between September and early November.

Obtain written or verbal consent at the time of vaccination for people aged over 16 years. For younger people, it is usual to get consent from a person with parental responsibility.

For Fluenz Tetra intranasal spray, give a single application of 0.1 ml in each nostril. The dose does not need to be repeated if the child or young person blows their nose or sneezes after administration.

Administer the other influenza vaccines by intramuscular injection (people taking anticoagulants and people with bleeding disorders may also be vaccinated intramuscularly).

  • For adults and children aged 1 year and older, use the deltoid area of the upper arm or the anterolateral aspect of the thigh.
  • For infants younger than 1 year of age, use the anterolateral aspect of the thigh.
  • Do not give immunisations into the buttock area.

Note: Some of the summaries of product characteristics (SPCs) for intramuscular inactivated influenza vaccines indicate that young children can be given either a 0.25ml or a 0.5ml dose. JCVI has advised that where these alternative doses are indicated, the 0.5ml dose of intramuscular inactivated influenza vaccine should be given to infants and children aged 6 months or older.

Ensure that the brand of vaccine, batch number, and administration site are accurately recorded in the person's records.

Influenza vaccines can be given at the same time as other live or inactivated vaccines — administer the vaccines at separate sites, preferably in a different limb (if appropriate).

If the vaccines need to be given in the same limb, use vaccination sites at least 2.5 cm apart.

If there is inadvertent administration of Fluenz Tetra to a person with a contraindication:

  • If the person is severely immunocompromised, consider the use of influenza antiviral prophylaxis. If antiviral prophylaxis is used, offer inactivated influenza vaccine immediately to provide ongoing protection for the current influenza season. If there is any uncertainty about management, seek specialist advice.
  • For all other people, advise them to seek medical advice if they develop influenza-like symptoms in the 4 days following administration of Fluenz Tetra.

Very severely immunocompromised healthcare professionals should not administer Fluenz Tetra intranasal spray, due to a theoretical risk of acquiring vaccine virus due to exposure to the live attenuated vaccine.

What are the adverse effects of influenza vaccines?

Common adverse effects after influenza immunisation (which usually disappear within 1–2 days without needing treatment), include:

  • Pain, swelling, or redness at the injection site
  • A small painless nodule (induration) at the injection site
  • Low-grade fever, malaise, shivering, or fatigue
  • Headache, myalgia, or arthralgia
  • Nasal congestion, rhinorrhoea, reduced appetite, and headache following administration of Fluenz Tetra nasal spray.

Rare adverse effects may include:

  • Neuralgia, paraesthesia, convulsions, and transient thrombocytopenia.
  • Vasculitis with transient renal involvement (very rare).
  • Neurological disorders such as encephalomyelitis and neuritis (very rare).

Report all serious suspected adverse reactions to influenza vaccines using the Yellow Card scheme (

Report any suspected adverse reactions to vaccines that are black triangle drugs, as they subject to intensive surveillance by the Medicines and Healthcare products Regulatory Agency (MHRA).

What information and advice should be given to people about influenza vaccines?

Advise the person or family/carers that:

  • The protection provided by the influenza vaccine lasts for about 1 year
  • After vaccination, antibody levels may take 10–14 days to reach a protective level
  • The influenza vaccine will not protect the person from other micro-organisms that can cause similar respiratory infections, such as the common cold and respiratory syncytial virus
  • People who have received the Fluenz Tetra nasal spray should avoid close contact with severely immunocompromised people for 1–2 weeks following vaccination, if possible
  • Adverse effects are generally minor, and usually disappear within 1–2 days without the need for treatment

They need to be vaccinated annually (usually before mid-November).

Provide sources of information and advice on the influenza vaccine and national influenza immunisation programme, including patient information leaflets published by Public Health England (PHE), available at


During this module you have learned:

  • Which at risk groups should be vaccinated
  • Which vaccine to use for whom and how to administer them
  • About the contraindications to influenza vaccine
  • About the adverse effects of influenza vaccine
  • How to manage people with egg allergy
  • What information and advice to give to people receiving influenza vaccine.


Run a report on the uptake of flu vaccine at the practice for at-risk groups over the past 5 years.

Record the percentage where the vaccine was given, not given, declined and where a contraindication was recorded.

Report on any trends within the practice.