Research and analysis

Evaluating the impact of national and regional measles catch-up activity on MMR vaccine coverage in England, 2023 to 2024

Updated 29 August 2024

Main messages

By the end of the campaign period (April 2024) there were increases in the number and percentage vaccinated with measles, mumps and rubella (MMR) vaccine, dose 1 (MMR1) and dose 2 (MMR2) in each of the cohorts assessed, with over 180,000 additional doses of MMR vaccine given during the evaluation period.

For MMR1, the largest increase was observed in children aged 15 months to 5 years of age (1.84 percentage point (pp) increase). For MMR2, the largest increase was observed in children aged 3 years and 7 months to 5 years of age (3.59 pp increase).

Over 13 percent of previously unvaccinated children under the age of 5 years were vaccinated with MMR1 during the campaign period compared to baseline.

There was geographical variation (by NHS commissioning region and integrated care board (ICB)) in the percentage point change in coverage for both doses of MMR across all cohorts.

For MMR1, the greatest increases in coverage in children aged under 5 years were observed in London, whilst the smallest increases were observed in the East of England.

For MMR2, the greatest increases in coverage in children aged under 5 years were observed in the North East and Yorkshire, with the smallest increase in the South West.

The largest coverage increases for MMR1 and MMR2 were consistently seen in people from African, Arab, other black, and white Gypsy and Irish Traveller ethnic groups, which are all groups with historically lower MMR coverage The smallest coverage increases for MMR1 and MMR2 were consistently seen in the white British ethnic group.

In children aged 3 years and 7 months to 5 years of age, the largest increase in MMR1 coverage was in black, black British, Caribbean, or African ethnicities (+3.09 pp); the largest increase in MMR2 coverage was in black, black British, Caribbean or African ethnicities (+4.88 pp).

For all cohorts for both MMR1 and MMR2, the greatest percentage change in coverage was observed in the most deprived deciles (decile 1), whilst the smallest percentage change was observed in the least deprived deciles (deciles 9 and 10).

Appropriately resourced and sustained efforts are required to continue to increase MMR vaccination coverage, particularly in areas and groups with the lowest coverage.

Introduction

The epidemiology of measles in England

Measles is a highly contagious viral infection transmitted by the respiratory route and can lead to severe complications and death (1). In 2022, there were an estimated 136,000 deaths globally, mostly among unvaccinated or under vaccinated children under the age of 5 years (1).

Since the turn of the century, confirmed cases of measles detected through national surveillance have followed patterns of comparatively low baselines (for example, less than 100 cases in England in 2001, 2005 and 2015) and periods of higher incidence (peaking at 1,920 cases in England in 2012) (2). The large 2012 outbreak mainly affected teenagers and was likely the effect of unprecedently low measles, mumps and rubella (MMR) vaccine uptake in the early 2000s (at a time when false associations between MMR and autism were being drawn) (3).

The UK achieved endemic measles elimination in 2016 and 2017, but by 2018 measles transmission had been re-established in the UK, at a time when Europe was experiencing large epidemics (4). As seen with many infectious diseases, interventions to limit the spread of COVID-19 between 2020 and 2022 led to extremely low measles case numbers (just 2 cases in England in 2021) (2). This resulted in the UK regaining measles elimination status in 2023 (reflecting 2022 surveillance data) (4). The incidence has increased again in 2023 in the UK and globally, so this is unlikely to be sustained (4).

Since the autumn of 2023, regional outbreaks and an overall national exceedance in measles cases led the UK Health Security Agency (UKHSA) to declare a national standard incident (5). Initially focussed on populations within the West Midlands, outbreaks have occurred in other regions (such as London). Outbreaks and sporadic cases across the country have resulted in the highest number of measles cases in England since 2012 (2,039 laboratory confirmed measles cases between 1 October 2023 and 27 June 2024), with 62.9% of cases (n=1,283) in children aged 10 years old and under (6). This has resulted in a renewed focus on population susceptibility and MMR coverage in England.

MMR vaccination coverage

Measles vaccination was first available in the UK in 1968. Prior to this date (and for a time after, given sub-optimal coverage) measles was endemic and led to infections in most children; only after the combined MMR vaccine was introduced in 1988 did vaccine coverage exceed 90% (7).

Given the highly infectious nature of the measles virus and efficacy of measles vaccination in inducing long-term immunity, the World Health Organization (WHO) specify a target 2-dose coverage of MMR vaccination at 95% to achieve and maintain measles elimination (8). This 95% target has never been met nationally; coverage peaked just short of this target (adjusted estimate) around 2009 to 2010 (9). Additionally, there are certain population groups (including migrant populations, traveller communities, and ultra-orthodox Jewish communities) and geographies (London and other inner-city areas) with lower MMR vaccine coverage who are at increased risk of infection (9).

Over the past decade, uptake of all childhood immunisations, including MMR, has continued to wane. By March 2024, 2 doses of the MMR vaccine had been received by just 85% of 5-year olds, with significantly lower coverage in some communities (10). Additionally, coverage has not recovered to pre-COVID-19 pandemic levels.

Previous campaigns to improve MMR coverage occurred nationally in 2008, 2013 and 2022. Campaigns specifically within London occurred in 2004 and early 2023, prior to a new national catch-up campaign being launched in response to declining vaccine coverage and increasing measles case rates in England.

National 2023 to 2024 catch-up activities

A new national catch-up campaign for MMR was launched by NHS England in November 2023 and included local and national call-recall activities as part of a package of measures encouraging MMR catch-up, in addition to various local and national NHS and UKHSA communications (11). The call and recall campaign occurred in 3 phases:

1. Local call and recall of children aged 12 months to 5 years inclusive by GPs in England, from November 2023 onwards.
2. National call and recall of children aged 6 to 11 years in England recorded as unvaccinated or partially vaccinated, from 5 February 2024 onwards.
3. National call and recall extended to include individuals aged 12 to 25 years old registered at a GP or resident in London, Greater Manchester, and the West Midlands, from 5 February 2024 onwards.

For phase 2, eligible cohorts were also targeted within schools with the support of School Age Immunisation Services.

Regional 2023 to 2024 catch-up activities

In addition to national activities, various regional efforts to improve vaccine uptake were locally devised, procured and delivered. For example, in the West Midlands, efforts focused on communications and community engagement to supplement the national campaign; these included clinics run in schools and community locations (such as libraries), and webinars and presentations for faith leaders, headteachers and governors, with integrated care board (ICB) system partners. Community outreach within target populations, and motivational interview training for NHS staff, further reinforced the local offer.

Data sources

UKHSA (formerly Public Health England) is responsible for providing data on population coverage for the routine childhood immunisation programmes (including MMR), at both national and lower geographical levels. Based on data submitted to local CHIS (Child Health Information Services) systems, as maintained by NHS England, geographically aggregated records are analysed and summarised by UKHSA on a quarterly basis in production of the COVER (Cover of Vaccination Evaluated Rapidly) outputs. These official statistics are produced with an approximate 3-month time lag, and report coverage of MMR at 2 years (MMR1 only) and 5 years (MMR1 and MMR2) of age; sub-analysis by geography (at national, regional, and upper-tier local authority level) is published, but detailed breakdown (for example by ethnicity or deprivation) is challenging due to the aggregate nature of the data.

Supplementary unpublished data collected annually by UKHSA summarises MMR coverage at other age thresholds (such as at 15 months, 18 months, and between the ages of 2 and 30), based directly on GP records submitted via ImmForm. Again, the aggregate nature of the data only allows for geography level analysis (at national, NHS region, ICB, sub-ICB and GP practice level) and not more frequently than once a year.

As of 2023, the NHSE and UKHSA have established a new real-time dataflow comprising individual-record data on MMR vaccination from GP records. This Immunisation Information System (IIS) MMR data is sourced from NHS England (based on GP record systems) and is in keeping with similar data streams initially established for COVID-19 and latterly influenza vaccination. This patient-level data set allows for more frequent and detailed analysis on MMR coverage by subgroups including ethnicity, small-area geography, deprivation, as well as temporal comparisons in vaccine coverage (such as before and after a catch-up campaign). As data is sourced from GP systems, it is dependent on the completeness of the electronic vaccine record and selection of the complete set of clinical codes used. Although data completeness in older-age groups will be lower, reliable estimates of any change in the proportion vaccinated will be possible for evaluations such as this one.

Evaluation aims and objectives

Evaluation aim

To assess the impact of 2023 to 2024 MMR catch-up activities on increasing the number and proportion of vaccinated individuals (MMR1 and MMR2), measured prior to (31 August 2023) and at the end of the catch-up period (30 April 2024).

Evaluation objectives

Objective 1

To calculate the numbers vaccinated and MMR1 proportion vaccinated (%) pre and post campaign by sex, geography, ethnicity, and deprivation in:

• cohort 1a: children aged between 15 months and 5 years in England

Objective 2

To calculate the numbers vaccinated and MMR1 and MMR2 proportion vaccinated (%) pre-and post-campaign, stratified by sex, geography, ethnicity, and deprivation in:

• cohort 1b: children aged between 3 years and 7 months, and 5 years in England
• cohort 2: children aged between 6 and 11 years in England
• cohort 3: people aged between 12 and 25 years in England

Objective 3

To draw conclusions on whether the 2023 to 24 MMR catch-up campaign increased MMR coverage in England overall, and within key populations.

Note: The lower age cut-offs for cohorts 1a and 1b were selected to identify catch-up activity, as opposed to routine vaccination given when children first become eligible (that is, 12 months for MMR1 and 3 years 4 months for MMR2). The lower bounds are therefore 3 months after children first become eligible.

Methods

Definitions of cohorts

This evaluation retrospectively defined cohorts of relevant populations as of 31 August 2023 and observed changes in the same population post-campaign to 30 April 2024. The local call and recall campaign has 2 sub-cohorts to reflect the age-related eligibility (including a 3-month buffer) for MMR1 and MMR2. The regional catch-up campaign also has 2 sub-cohorts to reflect the regions in which the regional campaign catch-up was implemented (intervention areas, Appendix 1) and those in which it was not (control areas).

Local call and recall (15 months to 5 years)

Cohort 1a: children in England aged 15 months to 5 years who have not received MMR1 by 31 August 2023.

Cohort 1b: children in England aged 3 years 7 months to 5 years who have not received MMR1 and/or MMR2 by 31 August 2023.

National call and recall (6 to 11 years)

Cohort 2: children in England aged 6 to 11 years who have not received MMR1 or MMR2 (or both) by 31 August 2023.

Regional catch-up (12 to 25 years)

Cohort 3a (control): people with a postcode of residence not in London, Greater Manchester, or the West Midlands aged 12 to 25 years who have not received MMR1 or MMR2 (or both) by 31 August 2023.

Cohort 3b (intervention): people with a postcode of residence in London, Greater Manchester, or the West Midlands aged 12 to 25 years who have not received MMR1 or MMR2 (or both) by 31 August 2023.

Denominator cohort

The denominator cohort is all people in IIS who meet the age criteria for inclusion in campaigns 1 to 3, irrespective of their vaccination status. Individuals not registered for primary care would not be captured in our study, which for children in England aged 0 to 4 years old has been estimated to be less than 1% (12).

Definitions

Patient age, sex and MMR dose were obtained from the IIS record.

Geography and index of multiple deprivation (IMD) decile were based on the person’s home postcode on 31 August 2023 as held in IIS.

Where postcode was missing, or it was unable to be mapped to an NHS region or ICB, patients were assigned to an unknown geography category.

Ethnic group was as recorded on IIS as of 31 August 2023.

Statistical analysis

Aggregated data were extracted from IIS for each cohort described above. All analyses were undertaken using R version 4.3.1.

In each cohort we calculated the proportion of each of the cohorts who received MMR1 or MMR2 (or both) vaccinations during the evaluation period (31 August 2023 to 30 April 2024), the change in the proportion vaccinated, and the proportion of previously unvaccinated people who were vaccinated. We described these proportions by demographic characteristics (age, sex, ethnicity, IMD decile, geography).

For campaign 3 (regional catch-up campaign), we further compared the outcomes of the vaccination campaigns for those ICBs included in the regional catch-up campaigns (London, Greater Manchester, or the West Midlands, detailed in Appendix 1) and the rest of England.

Ethics and governance

This evaluation has been commissioned, and therefore has governance oversight, from the national measles incident management team (IMT) established for the standard incident response.

This work is carried out under Regulation 3 of The Health Service (Control of Patient Information, COPI) Regulations 2002 which gives UKHSA explicit authority to receive confidential data under Regulations, 3(1), 3(2) and 3(3). These purposes are covered by UKHSA’s remit letter setting out our public health statutory legal functions UKHSA priorities for the year 2023 to 2024.

This evaluation did not require ethics committee approval. Data was handled and stored in compliance with the Data Protection Act (2018), guidelines established by the local Caldicott guardian and relevant UKHSA policies and procedures. Only the evaluation team had access to the data and identifying information was not included in evaluation outputs.

Results

Overall coverage change

By the end of the campaign (April 2024), there were increases in the number and percentage vaccinated with MMR1 and MMR2 in each of the cohorts assessed (Table 1, Table 2). For MMR1, the largest increase was observed in children aged 15 months to 5 years of age (1.8 pp) increase, +44,072 vaccinations). For MMR2, the largest increase was observed in children aged 3 years and 7 months to 5 years of age (3.59 pp increase, +35,025 vaccinations). The magnitude of gains in coverage decreased with increasing age of cohorts (Table 2), although there were more vaccines given to cohorts 2 and 3 overall +45,155 MMR1 and +48,114 MMR2 vaccinations (Table 1).

For MMR1, the largest percentage of previously unvaccinated children who were vaccinated during the campaign period was in the 15 months to 5 years age group (13.15%). For MMR2, the largest percentage of previously unvaccinated children who were vaccinated during the campaign period was in the 3 years 7 months to 5 years age group (13.94%). In the 6 to 11 years age group, there was a greater increase for MMR1 amongst previously unvaccinated individuals (3.43%) compared to MMR2 (2.71%). The same trend was observed in the 12 to 25 years age group, with 0.71% of previously unvaccinated individuals receiving MMR1, compared to 0.446% receiving MMR2. The percentage of unvaccinated individuals who were subsequently vaccinated decreased with increasing age of cohorts (Table 2). Further information on the numbers vaccinated is outlined in Appendix 2 and Appendix 3.

When stratified by sex, no significant differences were observed in either the percentage of unvaccinated individuals subsequently vaccinated or the pp change in vaccination in any cohort (Appendix 4).

Table 1. MMR1 and MMR2 number vaccinated by cohort (31 August 2023 to 30 April 2024)

Cohort	Cohort population	MMR1 number vaccinated	MMR2 number vaccinated
Cohort 1a: children aged 15 months to 5 years	2,391,460	+44,072	N/A
Cohort 1b: children aged 3 years 7 months to 5 years	976,255	+7,702	+35,025
Cohort 2: children aged 6 to 11 years	4,971,189	+23,773	+30,216
Cohort 3: people aged 12 to 25 years	10,486,986	+21,382	+17,898

Table 2. Vaccine coverage before and after the campaign, pp change in vaccine coverage and percentage of previously unvaccinated people who were subsequently vaccinated, by cohort (31 August 2023 to 30 April 2024)

Cohort	MMR1: % vaccinated before the campaign (baseline)	MMR1: % vaccinated after the campaign	MMR1: pp change in vaccine coverage	MMR1: % of previously unvaccinated people who were vaccinated with MMR1	MMR2: % vaccinated before the campaign (baseline)	MMR2: % vaccinated after the campaign	MMR2: pp change in vaccine coverage	MMR2: % of people without MMR2 who were vaccinated
Cohort 1a. Children aged 15 months to 5 years	85.98	87.83	1.84	13.15	-	-	-	-
Cohort 1b. Children aged 3 years 7 months to 5 years	87.39	88.18	0.79	6.26	74.27	77.86	3.59	13.94
Cohort 2. Children aged 6 to 11 years	86.08	86.56	0.48	3.43	77.60	78.21	0.61	2.71
Cohort 3. People aged 12 to 25 years	71.21	71.42	0.20	0.71	62.68	62.85	0.17	0.46
3a. Not included in regional catch-up	78.50	78.66	0.15	0.71	71.08	71.23	0.15	0.53
3b. Included in regional catch-up	57.36	57.66	0.30	0.71	46.69	46.90	0.20	0.38

Overall coverage change, by NHS region

There was variation in the increases in percentages vaccinated with MMR1 by NHS commissioning region for each cohort (Table 3). For children aged 15 months to 5 years (cohort 1a) and 3 years 7 months to 5 years (cohort 1b), the largest increases were observed in London (2.70 and 1.32 percentage points respectively), while the smallest increases were observed in the East of England (0.93 and 0.47 percentage points respectively). For children aged 6 to 11 years (cohort 2) and individuals aged 12 to 25 years (cohort 3) the largest increase was in the North West (0.82 and 0.31 percentage points respectively) and the lowest was in the South West (0.32 percentage points) and North East and Yorkshire (0.11 percentage points) respectively.

Table 3. MMR1 and MMR2 pp change in percent vaccinated, by cohort and NHS Region (31 August 2023 to 30 April 2024)

NHS Region	MMR1: cohort 1a	MMR1: cohort 1b	MMR1: cohort 2	MMR1: cohort 3	MMR2: cohort 1b	MMR2: cohort 2	MMR2: cohort 3
East of England	0.93	0.47	0.45	0.14	3.39	0.72	0.17
London	2.70	1.32	0.52	0.27	3.70	0.57	0.18
Midlands	1.84	0.80	0.48	0.20	4.06	0.66	0.18
North East and Yorkshire	1.18	0.60	0.45	0.11	4.25	0.58	0.11
North West	2.62	0.97	0.82	0.31	3.42	0.91	0.19
South East	1.79	0.62	0.32	0.15	3.24	0.40	0.14
South West	1.47	0.51	0.27	0.27	2.46	0.41	0.24

See cohort definitions

For children aged 3 years 7 months to 5 years of age (cohort 1b), the largest increases in MMR2 coverage were observed in the North East and Yorkshire (4.25 pp), followed by the Midlands (4.06 pp), with the smallest increase in the South West (2.46 pp) (Table 3). For children aged 6 to 11 years (cohort 2) the largest increase was in the North West (0.91 pp) and lowest in the South East (0.40 pp). For individuals aged 12 to 25 years (cohort 3) the largest increase was in the South West (0.24 pp) and the smallest increase in the North East and Yorkshire.

Overall coverage change, stratified by ICB

Table 4. MMR1 and MMR2 pp change in percent vaccinated, by cohort and ICB (31 August 2023 to 30 April 2024)

Cohort	MMR1: smallest increase	MMR1: largest increase	MMR2: smallest increase	MMR2: largest increase
1a. Children between the age of 15 months and 5 years	Bath and North East Somerset, Swindon and Wiltshire ICB (+0.60)	North Central London ICB (+3.32)	N/A	N/A
1b. Children between the age of 3 years 7 months and 5 years	Bath and North East Somerset, Swindon and Wiltshire ICB (+0.23)	North East London ICB (+1.59)	Shropshire, Telford and Wrekin ICB (+1.87)	Nottingham and Nottinghamshire ICB (+5.93)
2. Children between the age of 6 and 11 years	North Central London ICB (+0.45)	Greater Manchester ICB (+1.43)	Buckinghamshire, Oxfordshire and Berkshire West ICB, Sussex ICB (+0.31 for both)	Greater Manchester ICB (+1.43)
3. People between the age of 12 and 25 years	North East and North Cumbria ICB (+0.09)	Bristol, North Somerset and South Gloucestershire ICB (+0.63)	Buckinghamshire, Oxfordshire and Berkshire West ICB (+0.08)	Bristol, North Somerset and South Gloucestershire ICB, Somerset ICB (+0.97 for both)

Table 4, Figure 1, and Figure 2 show that there was variation in the percentage point change between ICBs for both MMR doses across all cohorts. Data by individual ICB is presented in Appendix 5.

Figure 1. Percentage point change in percent vaccinated with MMR dose 1 and 2 by cohort and ICB

Note: X axis scales differ between cohorts (facets).

Table 4, Figure 1 and Figure 2 show that there was variation in the percentage point change between ICBs for both MMR doses across all cohorts. Data by individual integrated care board is presented in Appendix 5 and can also be viewed in the accompanying supplementary tables.

Figure 2. Cohort 1a (15 months to 5 years) MMR1 change in percent vaccinated by ICB

Table 4, Figure 1 and Figure 2 show that there was variation in the percentage point change between ICBs for both MMR doses across all cohorts. Data by individual integrated care board is presented in Appendix 5.

4.4. Overall coverage change, stratified by ethnicity

Table 5. MMR1 and MMR2 pp change in percent vaccinated by cohort and aggregated ethnicity (31 August 2023 to 30 April 2024

Cohort	MMR1: smallest increase	MMR1: largest increase	MMR2: smallest increase	MMR2: largest increase
1a. Children between the age of 15 months and 5 years	White (+1.43)	Black, black British, Caribbean, or African (+3.09)	N/A	N/A
1b. Children between the age of 3 years 7 months and 5 years	White (+0.45)	Black, black British, Caribbean, or African (+1.89)	White (+3.18)	Black, black British, Caribbean, or African (+4.88)
2. Children between the age of 6 and 11 years	White (+0.16)	Black, black British, Caribbean, or African (+1.37)	White (+0.33)	Black, black British, Caribbean, or African (+1.33)
3. People between the age of 12 and 25 years	White (+0.12)	Black, black British, Caribbean, or African (+0.39)	White (+0.12)	Black, black British, Caribbean, or African (+0.28)

Note: A total of 2,322,942 records (12%) were not included due to having an unknown ethnicity.
Ethnicity was aggregated according to the ONS Census 2021 Ethnic group classification 6a (13).

Figure 3. Percentage point change in percent vaccinated with MMR dose 1 and 2 by cohort and disaggregated ethnic group

Note: X axis scales differ between cohorts (facets).

Figure 3, Table 5 and Appendix 6 show that the largest coverage increases for MMR1 and MMR2 were consistently seen in people from African, Arab, other black, and white Gypsy and Irish Traveller ethnic groups. The smallest coverage increases for MMR1 and MMR2 were consistently seen in the white British ethnic group.

4.5. Overall coverage change, stratified by IMD decile

Table 6. MMR1 and MMR2 pp change in percent vaccinated by cohort and IMD decile

Cohort	MMR1: smallest increase	MMR1: largest increase	MMR2: smallest increase	MMR2: largest increase
1a. Children between the age of 15 months and 5 years	1.39 (decile 9)	2.51 (decile 1)	N/A	N/A
1b. Children between the age of 3 years 7 months and 5 years	0.37 (decile 10)	1.25 (decile 1)	2.24 (decile 10)	5.21 (decile 1)
2. Children between the age of 6 and 11 years	0.22 (Decile 10)	0.85 (decile 1)	0.34 (decile 10)	0.99 (decile 1)
3. People between the age of 12 and 25 years	0.13 (decile 9 and decile 10)	0.29 (decile 1)	0.13 (decile 9 and decile 10)	0.22 (decile 1)

Note: A total of 63,777 records (0.3%) were not included due to having an unknown IMD decile.

IMD decile 1 = the most deprived 10% of neighbourhoods nationally; IMD decile 10 = the least deprived 10% of neighbourhoods.

Figure 4. Percentage point change in percent vaccinated with MMR dose 1 and 2 by cohort and IMD decile

Note: A total of 63,777 records (0.3%) were not included due to having an unknown IMD decile. X axis scales differ between cohorts (facets).

For all cohorts for both MMR1 and MMR2, the greatest percentage point change in coverage was observed in the most deprived deciles (that is, decile 1).

Discussion

Principal findings

During the evaluation period there was an overall percentage point increase in coverage of MMR1 and MMR2 in all age groups. The greatest increase in MMR1 coverage was observed in children between the age of 15 months and 5 years (cohort 1a), with an increase of 1.84 percentage points. The greatest increase in MMR2 coverage was observed in children between the age of 3 years 7 months and 5 years (cohort 1b), with an increase of 3.59 percentage points. The gain in coverage was lower with increasing age.

While overall gains in coverage appear modest, when assessing the impact of catch-up activities on previously unvaccinated individuals, over 13% of previously unvaccinated children under the age of 5 years were vaccinated with MMR1 during the campaign period compared to baseline. This compares to 10.8% of the 10 to 16 year old population vaccinated in the 2013 MMR catch-up campaign in England (14).

Significantly, there were larger gains in both MMR1 and MMR2 coverage in areas with lower pre-campaign coverage which were targeted with additional regional catch-up activities (London, the North West and the Midlands) during the period. It is noteworthy that the largest increase in the percentage of the previously unvaccinated population under 12 years old vaccinated during the campaign was in London. This contrasts with the 2013 catch-up campaign, where the impact seen in London was lower than in all other regions (14).

The largest gains were also seen in the most deprived populations and among ethnic groups with lower baseline coverage of MMR vaccination (for example, individuals from other Black, African, and Arab ethnic backgrounds). The campaign appears to have been effective at reaching those most in need, and reducing inequalities in the populations most susceptible to measles (and mumps and rubella) .

Cohort 3 (individuals aged 12 to 25 years old) saw the smallest increase in coverage during the catch-up campaign period. Catch-up activities for this age group were regionally targeted, specifically in London, Greater Manchester and the West Midlands, and it is encouraging to see the small increase in coverage achieved in these regions. Any increase outside of these areas would have been a benefit of the increased MMR activity and communications strategies and local outreach activities. Additionally, the recording of vaccination history in primary care records is known to degrade with increasing age and therefore the proportion unvaccinated in this age group is likely to be smaller than estimated in our study. Therefore, the magnitude of the change in proportions unvaccinated after the campaign period are uncertain.

The WHO specify a target 2-dose coverage of MMR vaccination at 95% to achieve and maintain measles elimination (8). While the 2023 to 2024 catch-up activities have led to important gains in coverage in more susceptible communities, it remains well below the target and the risk of ongoing measles transmission and outbreaks remain. Furthermore, there remains a disproportionate risk of disease amongst those from low socioeconomic groups and ethnic minorities.

This catch-up campaign together with others that precede it, shows that despite the positive impact on coverage and inequalities, achieving and sustaining the high coverage required for elimination cannot be done through resource intensive periodic catch-up activity alone. It will only be achieved through appropriately resourced and sustained efforts in the routine offer of vaccination, in line with the recommendations comprehensively detailed in NICE (15) and WHO guidance (8).

Strengths and limitations

Understanding the specific reasons behind the change in vaccination status was beyond the scope of this study, and therefore we were not able to attribute changes in vaccine status directly to the specific elements of catch-up activity such as call-recall or communications campaigns.

This study required a retrospective analysis of the vaccination status of the eligible population before the vaccine campaigns started. However, an interruption to the flow of the eligible population data (the denominator) between September 2023 and June 2024 led to a period of unknown population change and thus the study cohorts and baseline vaccination status were designated at 31 August 2023. Some national call and recall activity continued to the end of March and it is possible that because of the time required for people to respond to a late call, as well as continuing local activity, not all vaccination events from late activity have been completely captured by the end point of the evaluation.

MMR data completeness reduces with increasing age. This under-ascertainment of true vaccination coverage is difficult to quantify but is likely to be affected by population movement and therefore areas with high population mobility such as London will be disproportionately affected. These missing records will have led to an underestimation of the baseline coverage at the start of the study period. New vaccine events recorded in this dataset, however, are reliable for the purposes of this evaluation and for this reason, we have reported on the change in coverage as being a more reliable indicator for the evaluation than absolute coverage.

Additionally, the figures reported for the percentage of the previously unvaccinated population who were vaccinated in the campaign are dependent on the accuracy of the unvaccinated population. This measure could be regarded as an underestimation of the impact of the catch-up campaign, because the unvaccinated population will be overestimated in older ages. The coverage estimates and changes in coverage presented in this study should not therefore be used as absolute but indicate the direction and relative magnitude of increases amongst different groups.

We excluded individuals without a valid postcode and with a postcode of residence outside of England (such as Wales and Scotland) who were still registered for primary care in England. It is therefore possible that a small number of individuals will have been misclassified as unvaccinated or sub-vaccinated because they were registered with England but had their vaccinations recorded in another national healthcare system.

Conclusion

This evaluation is the first in England to use a national record level dataset to evaluate the impact of a vaccine catch-up campaign and to show differential impact by deprivation and ethnicity.

There were increases in MMR1 and MMR2 coverage during the campaign period in each of the cohorts assessed. The magnitude of coverage gain decreased with increasing age of cohorts.

The greatest coverage gains were observed in London, amongst people from other black, African, Arab, and white Gypsy and Irish Traveller ethnic groups, and in the most deprived deciles. These are areas and groups with some of the lowest MMR vaccination coverage.

The catch-up campaign had a positive impact on coverage overall, comparable to that of previous campaigns. The impact was greatest in groups with lower initial coverage, demonstrating the positive impact on deprivation and ethnicity inequalities.

While the 2023 to 2024 catch-up activities have led to important gains in coverage in more susceptible communities, it remains well below the target and the risk of ongoing measles transmission and outbreaks remain. Furthermore, there remains a disproportionate risk of disease amongst those from low socioeconomic groups and ethnic minorities.

This catch-up campaign, together with others that precede it, shows that despite the positive impact on coverage and inequalities, achieving and sustaining the high coverage required for elimination cannot be done through resource-intensive periodic catch-up activity alone. It will only be achieved through appropriately resourced and sustained efforts in the routine offer of vaccination, in line with the recommendations comprehensively detailed in NICE (15) and WHO guidance (8).

References

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2. UKHSA. ‘Confirmed cases of measles, mumps and rubella in England and Wales: 1996 to 2022’ 2023

3. Millward G. Chapter 5 MMR in: ‘Vaccinating Britain: Mass Vaccination and the Public since the Second World War’ Manchester University Press 2019

4. UKHSA. ‘National measles guidelines’ 2024

5. Wise J. ‘Measles: Birmingham outbreak declared a national incident and likely to spread’ British Medical Journal 2024: volume 384

6. UKHSA ‘National Measles Standard Incident – measles epidemiology (from October 2023)’ 2024

7. UKHSA. ‘Measles: the green book, chapter 21’ (last viewed 12 July 2024)

8. WHO. ‘Measles vaccines: WHO position paper’ 28 April 2017

9. UKHSA. ‘Risk assessment for measles resurgence in the UK 2023’

10. UKHSA. ‘Quarterly vaccination coverage statistics for children aged up to 5 years in the UK (COVER programme): January to March 2024’ 28 June 2024

11. NHS England. ‘Confirmation of national vaccination and immunisation catch-up campaign for 2023 to 2024’ (updated 1 November 2023)

12. Pereira R. ‘Are there really 120,000 young children who are not registered with a GP?’ 2019

13. Office for National Statistics. ‘Ethnic group classifications: Census 2021 2023’

14. Simone B, Balasegaram S, Gobin M and others. ‘Evaluation of the measles, mumps and rubella vaccination catch-up campaign in England in 2013’ Vaccine 2014: volume 32, issue 36, pages 4,681 to 4,688

15. National Institute for Health and Care Excellence. ‘NICE guideline [NG218] Vaccine uptake in the general population’ 2022

Appendix 1. Regional campaign intervention areas

Regions eligible to be included in the regional catch-up activities

West Midlands:

• NHS Black Country ICB
• NHS Birmingham and Solihull ICB
• NHS Coventry and Warwickshire ICB
• NHS Herefordshire and Worcestershire ICB
• NHS Shropshire, Telford and Wrekin ICB
• NHS Staffordshire and Stoke-on-Trent ICB

London:

• NHS North Central London ICB
• NHS North East London ICB
• NHS North West London ICB
• NHS South East London ICB
• NHS South West London ICB

Greater Manchester:

• NHS Greater Manchester Integrated Care Board

Regions excluded from the regional catch-up activities

All other ICBs.

Appendix 2. MMR1 number vaccinated pre and post campaign and post-campaign coverage (%)

Cohort	MMR1: pre-campaign	MMR1: post-campaign	MMR1: post-campaign coverage %
1a. Children between the age of 15 months and 5 years	2,056,259	2,100,331	87.83%
1b. Children between the age of 3 years 7 months and 5 years	853,183	860,885	88.18%
2. Children between the age of 6 and 11 years	4,279,085	4,302,858	86.56%
3. People between the age of 12 and 25 years	7,468,097	7,489,479	71.42%

Appendix 3. MMR2 number vaccinated pre and post campaign and post-campaign coverage (%)

Cohort	MMR2: pre-campaign	MMR2: post-campaign	MMR2: post-campaign coverage
1b. Children between the age of 3 years 7 months and 5 years	725,045	760,070	77.86%
2. Children between the age of 6 and 11 years	3,857,570	3,887,786	78.21%
3. People between the age of 12 and 25 years	6,573,015	6,590,913	62.85%

Appendix 4. MMR1 and MMR2 coverage by sex

MMR1 vaccine coverage before and after the campaign, pp change in vaccine coverage and percentage of previously unvaccinated people who were subsequently vaccinated, by cohort and sex (31 August 2023 to 30 April 2024)

Cohort	Females: % vaccinated before the campaign	Females: % vaccinated after the campaign	Females: absolute change in vaccine coverage	Females: % of previously unvaccinated people who were vaccinated with MMR1	Males: % vaccinated before the campaign	Males: % vaccinated after the campaign	Males: absolute change in vaccine coverage	Males: % of people without MMR2 who were vaccinated
1a. Children aged 15 months to 5 years	86.09	87.93	1.84	13.24	85.89	87.73	1.84	13.06
1b. Children aged 3 years 7 months to 5 years	87.49	88.29	0.79	6.35	87.3	88.08	0.78	6.17
2. Children aged 6 to 11 years	86.09	86.57	0.48	3.46	86.06	86.54	0.48	3.41
3. People aged 12 to 25 years	70.58	70.8	0.22	0.74	71.83	72.02	0.19	0.67

Note: A total of 2,142 records (0.01%) were not included due to having an unknown sex.

MMR2 vaccine coverage before and after the campaign, pp change in vaccine coverage and percentage of previously unvaccinated people who were subsequently vaccinated, by cohort and sex (31 August 2023 to 30 April 2024)

Cohort	Females: % vaccinated before the campaign	Females: % vaccinated after the campaign	Females: absolute change in vaccine coverage	Females: % of previously unvaccinated people who were vaccinated with MMR1	Males: % vaccinated before the campaign	Males: % vaccinated after the campaign	Males: absolute change in vaccine coverage	Males: % of people without MMR2 who were vaccinated
1a. Children aged 15 months to 5 years	-	-	-	-	-	-	-	-
1b. Children aged 3 years 7 months to 5 years	74.60	78.14	3.55	13.96	73.96	77.58	3.63	13.93
2. Children aged 6 to 11 years	77.67	78.28	0.61	2.72	77.53	78.14	0.61	2.71
3. People aged 12 to 25 years	62.32	62.50	0.18	0.47	63.03	63.19	0.16	0.44

Note: A total of 2,142 records (0.01%) were not included due to having an unknown sex.

Appendix 5. Percent point change in percent vaccinated with MMR dose 1 and 2 by cohort and ICB

ICB name	MMR1: 15 months to 5 year	MMR1: 3 year 7 months to 5 years	MMR1: 6 years to 11 years	MMR1: 12 years to 25 years	MMR2: 3 year 7 months to 5 years	MMR2: 6 years to 11 years	MMR2: 12 years to 25 years
NHS Bath and North East Somerset, Swindon and Wiltshire ICB	0.60	0.23	0.21	0.15	2.01	0.37	0.17
NHS Bedfordshire, Luton and Milton Keynes ICB	1.01	0.52	0.55	0.11	3.32	0.80	0.10
NHS Birmingham and Solihull ICB	2.59	1.40	0.76	0.34	4.82	0.91	0.31
NHS Black Country ICB	2.42	1.11	0.60	0.21	4.33	0.72	0.16
NHS Bristol, North Somerset and South Gloucestershire ICB	2.85	0.93	0.38	0.63	2.60	0.55	0.38
NHS Buckinghamshire, Oxfordshire and Berkshire West ICB	2.43	0.64	0.27	0.10	2.10	0.31	0.08
NHS Cambridgeshire and Peterborough ICB	1.06	0.58	0.49	0.17	4.04	0.88	0.22
NHS Cheshire and Merseyside ICB	2.35	0.68	0.32	0.11	2.67	0.48	0.11
NHS Cornwall and the Isles of Scilly ICB	2.11	0.73	0.20	0.15	2.96	0.35	0.20
NHS Coventry and Warwickshire ICB	2.68	0.96	0.72	0.30	3.13	0.68	0.24
NHS Derby and Derbyshire ICB	0.93	0.50	0.36	0.14	4.19	0.62	0.17
NHS Devon ICB	0.96	0.38	0.24	0.14	2.48	0.37	0.17
NHS Dorset ICB	0.77	0.37	0.24	0.12	2.10	0.33	0.11
NHS Frimley ICB	2.77	0.75	0.42	0.20	2.13	0.48	0.16
NHS Gloucestershire ICB	0.82	0.34	0.30	0.25	2.76	0.45	0.30
NHS Greater Manchester ICB	3.01	1.26	1.43	0.55	4.26	1.43	0.27
NHS Hampshire and Isle of Wight ICB	1.90	0.67	0.40	0.16	3.39	0.53	0.14
NHS Herefordshire and Worcestershire ICB	2.24	0.63	0.37	0.18	2.49	0.43	0.17
NHS Hertfordshire and West Essex ICB	0.74	0.36	0.46	0.14	2.84	0.61	0.16
NHS Humber and North Yorkshire ICB	1.11	0.59	0.37	0.10	4.07	0.58	0.13
NHS Kent and Medway ICB	1.11	0.51	0.33	0.23	4.50	0.40	0.23
NHS Lancashire and South Cumbria ICB	2.25	0.82	0.41	0.13	2.91	0.52	0.14
NHS Leicester, Leicestershire and Rutland ICB	1.05	0.48	0.27	0.23	4.86	0.68	0.26
NHS Lincolnshire ICB	1.18	0.81	0.50	0.11	4.63	0.79	0.12
NHS Mid and South Essex ICB	1.14	0.54	0.40	0.11	3.59	0.59	0.10
NHS Norfolk and Waveney ICB	0.84	0.43	0.41	0.19	3.46	0.82	0.26
NHS North Central London ICB	3.32	1.56	0.45	0.22	4.27	0.50	0.16
NHS North East London ICB	3.23	1.59	0.55	0.28	4.08	0.54	0.19
NHS North East and North Cumbria ICB	1.15	0.57	0.52	0.09	2.95	0.58	0.09
NHS North West London ICB	1.95	1.04	0.39	0.25	3.95	0.62	0.20
NHS Northamptonshire ICB	0.78	0.40	0.27	0.12	4.23	0.37	0.11
NHS Nottingham and Nottinghamshire ICB	1.25	0.55	0.35	0.11	5.93	0.65	0.11
NHS Shropshire, Telford and Wrekin ICB	2.26	0.69	0.52	0.12	1.87	0.60	0.09
NHS Somerset ICB	2.37	0.65	0.32	0.39	2.61	0.41	0.35
NHS South East London ICB	2.50	1.27	0.59	0.26	2.82	0.50	0.15
NHS South West London ICB	2.57	1.16	0.65	0.36	3.21	0.68	0.23
NHS South Yorkshire ICB	1.05	0.57	0.37	0.15	5.49	0.55	0.16
NHS Staffordshire and Stoke-on-Trent ICB	2.17	0.67	0.39	0.11	2.06	0.52	0.11
NHS Suffolk and North East Essex ICB	0.84	0.45	0.42	0.13	3.43	0.74	0.18
NHS Surrey Heartlands ICB	2.51	0.99	0.25	0.14	3.39	0.42	0.11
NHS Sussex ICB	0.74	0.33	0.24	0.11	3.30	0.31	0.13
NHS West Yorkshire ICB	1.33	0.66	0.46	0.11	5.05	0.59	0.11

Appendix 6. Percent point change in percent vaccinated with MMR dose 1 and 2 by cohort and ethnicity

Note: The group with the largest pp increase (excluding ‘unknown’) in each cohort is highlighted in bold.

Ethnicity	MMR1: 15 months to 5 years	MMR1: 3 year 7 months to 5 years	MMR1: 6 years to 11 years	MMR1: 12 years to 25 years	MMR2: 3 year 7 months to 5 years	MMR2: 6 years to 11 years	MMR2: 12 years to 25 years
African	3.05	1.90	1.66	0.50	5.00	1.57	0.35
Any other Asian background	2.03	0.89	0.65	0.40	3.72	0.76	0.30
Any other black background	3.26	1.96	1.08	0.30	5.04	1.04	0.23
Any other mixed background	2.02	0.74	0.31	0.22	3.48	0.56	0.19
Arab	2.33	0.95	2.02	0.62	3.67	1.62	0.47
Bangladeshi	2.47	0.99	0.49	0.33	4.05	0.52	0.22
Caribbean	2.97	1.71	0.48	0.13	4.00	0.68	0.11
Chinese	1.56	0.52	0.66	0.33	2.02	1.22	0.22
Gypsy or Irish Traveller	2.89	2.61	0.57	0.15	5.97	0.63	0.10
Indian	1.86	0.78	0.54	0.28	3.12	0.72	0.23
Other ethnic group	2.42	1.08	0.62	0.34	4.17	0.77	0.27
Pakistani	2.23	0.83	0.49	0.23	4.62	0.61	0.16
Unknown	3.00	3.32	2.26	0.41	5.93	2.06	0.28
White - British	1.37	0.39	0.13	0.09	3.11	0.30	0.11
White - Irish	2.16	1.13	0.32	0.25	3.31	0.42	0.18
White - Other	1.79	0.75	0.36	0.27	3.57	0.55	0.19
White and Asian	1.68	0.56	0.29	0.22	3.43	0.41	0.19
White and Black African	2.10	1.03	0.89	0.40	4.31	1.03	0.27
White and Black Caribbean	2.13	0.78	0.30	0.16	4.59	0.61	0.15