In a further effort to protect against the impact of COVID-19 in the coming autumn and winter months, the UK government announced last week ‘the biggest flu vaccination programme in history.’

The annual influenza vaccine is normally available to adults over the age of 65 and certain other vulnerable groups. For the 2020/21 season, eligibility for the influenza vaccine has been extended to wider groups of people including all adults over 50 years or those with close contact of people shielding from COVID-19.

The change will mean that the flu vaccine will become available to around 30 million people in September 2020, around half of the UK population.

 

How does the flu vaccine work?

To explain simply, vaccines introduce a small, harmless amount of an organism (e.g. virus or bacteria) into the body – either a weakened (attenuated) or killed (inactivated) organism or genetic material or molecules from it. This is not enough to cause illness in the recipient, but it will trigger an immune response. This response includes the production of antibodies specific to that organism. These unique antibodies remain in the blood after vaccination and will be activated if the person is ever infected with that particular organism again.

Influenza (flu) is caused by the influenza virus, of which there are several different types. The flu viruses that circulate each year and can cause most flu outbreaks to fall into two main groups, A and B. Within those broad groups there are different subtypes depending on the proteins (called hemagglutinin [H] and neuraminidase [N]) on their surface. For example, the ‘swine flu’ pandemic of 2009 was caused by an influenza virus type A (H1N1). These subtypes then undergo further genetic changes over time which produces different strains each year.

The annual influenza vaccine is given from September each year, and typically covers two A strains (H1N1 and H3N2) along with B strains that are expected to be circulating in the coming autumn/winter months. The annual vaccine will therefore not protect against all flu viruses, but it will protect against those most likely to cause potential flu outbreaks in the coming season.

 

Who is normally eligible for the flu vaccine?

In the UK, the annual influenza vaccine is available to those who are considered most vulnerable and at risk of complications if they get flu or people who come into contact with them. Last season (autumn/winter 2019/2020) this included:

  • Adults aged 65 years and over
  • Pregnant women
  • Children in primary school and younger children aged 2 and 3 years
  • People with long-term medical conditions, including respiratory, heart, liver, kidney and neurological diseases, diabetes and those with immunosuppression
  • People living in long-term residential/care facilities
  • People working in health or social care
  • Carers/close contacts of vulnerable people

The specific type of flu vaccine and how it is given will differ between groups. For example, otherwise healthy children will usually be given the live, weakened flu vaccine via a nasal spray. Older and vulnerable people will usually be given the inactivated flu vaccine via injection.

 

How have the recommendations changed for 2020?

In May 2020, Public Health England (PHE) issued a letter recognising the demands and challenges that COVID-19 has placed upon the healthcare service but emphasising that the autumn/winter 2020/21 flu vaccination programme was ‘more important than ever’ and should go ahead as planned. At that time PHE said that coverage would include the same groups as last year, but said that ‘this may change if the programme is expanded.’

Last week the UK government announced that eligibility would be extended. Detailed advice from the PHE or NHS England on eligibility for the vaccine are awaited. BBC News listed that the following groups will now be invited for vaccination in autumn 2020, in addition to those groups already eligible:

  • People required to shield from COVID-19 and those that live with them
  • Children aged 11 to 12 years in Year 7 (prior eligibility covered only to primary Year 6)
  • Adults aged 50 years and over (after vaccination of those aged over 65 years)

Last year, 25 million were invited to receive vaccination (though only 15 million received accepted). This year would see the number of invites increase to 30 million.

 

How will the flu vaccine help the COVID-19 pandemic?

The influenza vaccine won’t directly prevent someone from becoming infected with COVID-19. However, extending eligibility for the flu vaccine could have several effects.

Last season 2019/20 there were nearly 8,000 deaths in England associated with influenza. At the height of the flu season, acute respiratory illnesses accounted for around a quarter of all GP consultations and 1 in 5 emergency department attendances. There is a risk that the healthcare system could become overwhelmed with both COVID and seasonal flu circulating at the same time. As Public Health England say ‘Flu vaccination is one of the most effective interventions we have to reduce pressure on the health and social care system this winter.’

People who are most vulnerable to flu, such as older adults and those with existing health problems, are also the same people who are most vulnerable to COVID-19. Therefore ensuring they are vaccinated against seasonal flu, alongside infection control and social distancing measures, will help them to remain as protected as possible.

The aim is to commence vaccination of eligible groups from beginning September and complete by end November 2020.

 

Reading list

    1. Public Health England. The national flu immunisation programme 2020/2021. Letter published 14 May 2020.
    2. Public Health England. Surveillance if influenza and other respiratory viruses in the UK. Winter 2019 to 2020. June 2020
    3. NHS. Flu vaccine overview. Updated 16 July 2019
    4. Centers for Disease Control and Prevention. Influenza (flu). Updated July 24, 2020.