Extension of influenza immunization program to children in England – Future plans

KEYWORDS:

• children
• Fluenz® tetra
• flu
• influenza
• immunization
• live attenuated
• LAIV
• school
• vaccine

Introduction

The aim of the national influenza (flu) immunization program is to reduce the morbidity and mortality caused by influenza in the UK each winter. This is achieved by offering direct protection against influenza to persons in clinical risk groups and since 2013/14 cohorts of ‘healthy’ children, this includes children aged 2 to 7 y and indirect protection to the whole population by immunizing children and reducing transmission.¹

Until 2012 the UK national flu immunization program recommended that influenza vaccine be offered to the following risk groups; persons aged 65 y and over, people in clinical at risk groups (aged 6 months to under 65 y), carers, pregnant women and occupational groups delivering health or social care with direct patient or client contact.¹ Following the emergence of the novel influenza A H1N1pdm09 influenza virus in the pandemic of 2009, which resulted in an increase in cases of influenza in children during that year² the UK Secretary of State for Health asked the Joint Committee of Vaccination and Immunisation (JVCI) to review the seasonal influenza vaccination program and provide advice and recommendations on possible extensions of the program to include at-risk age groups within the healthy population. The advice of the JVCI was that the influenza immunization program should be extended to include all children aged 2 y to less than 17 y. It was recognized that this would need to be a phased extension to the immunization program rolled out over a number of y.^3,4

Rationale and aspirations for the revised influenza immunization program

Children are ‘super-spreaders’ of the influenza virus.⁵ The mixing patterns of children mean they can transmit influenza to many different groups and vulnerable people; for example, pregnant women, siblings, elder grandparents. The aspirations for the extension of the immunization program to children are that by reducing the number of influenza cases among children there will be a reduction in the levels circulating virus in the communities local to those immunized, and an interruption to the transmission of influenza as a consequence of having less susceptible individuals in the population. Reduced transmission of influenza also is expected to provide added protection to vulnerable individuals who are either unvaccinated or have responded sub-optimally to their own immunization. The primary aim of the revised influenza immunization program is to reduce morbidity and mortality caused by influenza in the general population.⁴

Program roll out and phases

Table 1 shows the phases of the roll out of the revised influenza immunization program. Evidence shows that uptake of influenza vaccine is much lower when offered at GP or pharmacy compared to when it is offered in schools.⁶ To illustrate the enormity of this task; in the most recent phase, 1.2 million school Year 1 and 2 children (5 to 7 year olds) were offered influenza vaccine in 17,000 primary schools spread across 149 local authorities through England. The results of recent influenza vaccine pilot studies (2014/15) in which all primary school children were given the nasal spray vaccine found a 94% reduction in visits to GP for influenza-like illness in this age group. A 74% reduction in attending the emergency department for respiratory illness and a 93% reduction in hospital admissions in primary school age children was observed. Interestingly, a 59% reduction in adult influenza like illness consultations with GPs in pilot areas compared to non-pilot areas was also observed.⁷

Table 1. The phases of the revised influenza immunization program roll out in England from 2013–16.

Year	Phase of roll out
2013/14	GPs offered to 2 and 3 year olds
	GPs contracted to immunize at risk children (6 m-18 y)
	7 pilots in primary school age children (1 area invited children to attend GP/Pharmacy for vaccination)
2014/15	GPs offered to 2, 3 and 4 year olds
	GPs contracted to immunize at risk children (6 m-18 y)
	7 areas continued primary school age pilots
2015/16 (phase 2 – primary school age children)	GPs offered to 2, 3 and 4 year olds (8000+ practices in England)
	5 areas maintaining provision as per their primary school pilot models
	All children of Year 1 and 2 school age primarily being offered vaccine in their schools (17,000 schools)

Uptake ambition and results for 2015–16

It is a requirement of the extension of the influenza immunization program to children that every eligible ‘healthy’ child is offered the nasal spray influenza vaccine. The uptake ambition for 2015–16 was 40–60% (which was a modeling parameter⁸); however, it was considered important that uptake be congruent across all localities and sectors of the population. The uptake for all GP-registered 2 year olds was 35.4%, 37.7% for 3 year olds and 30.0% for 4 year olds in 2015–16. The national uptake for children of primary school age in 2015–16: 54.4% in children school years 1 age (aged 5 rising to 6 years); 52.9% in children school years 2 age (aged 6 rising to 7 years); 53.6% in children school years 1 and 2 age; 55.6% in children school years 1 and 2 age in local authorities (LAs) vaccinating through a school delivery model; 32.6% in children school years 1 and 2 age in LAs vaccinating through a GP delivery model; 16.1% in children school years 1 and 2 age in LAs vaccinating through a pharmacy delivery model. These results therefore show encouraging levels of uptake for the first year of vaccinating all children of school years 1 and 2 age in England. In 2016 to 2017, the school-age program will be extended to all children of school year 3 age.⁹

Provisional roll out

Dependent on the NHS Spending Review and the subsequent prioritization process for Public Health programs in England, a provisional roll out plan is as follows. As of 2016/17 it is proposed that, as well as children aged 2 y to under 7 y all school Year 3 age children (7 to 8 year olds) be offered the influenza vaccine at school.¹⁰ Rollout beyond 2016/17 is still to be confirmed. Once all primary school age cohorts are being offered vaccination the rollout will pause to allow full review and evaluation of the impact of the program.

Conclusion

The full impact of the extension of the flu immunization program to children remains to be seen. Initial results from the pilot studies suggest the recommendations of the JCVI have resulted in reduced morbidity not only for the young children vaccinated but also for adults in the local population. These results show great promise for the future in providing protection against the influenza virus.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.