Official Statistics

Quality and methodology information: maternal respiratory syncytial virus (RSV) vaccine coverage estimates in England

Published 5 March 2026

Applies to England

About this report

This quality and methodology information (QMI) report outlines the approach used for the production of the official statistics on maternal respiratory syncytial virus (RSV) vaccine coverage, published by the UK Health Security Agency (UKHSA). This QMI report supports users in understanding the strengths and limitations of the data, methods and statistics, ensuring UKHSA is compliant with the quality standards stated in the Code of Practice for Statistics.

 The report covers:

• the strengths and limitations of the data used to produce the statistics
• the methods used to produce the statistics
• the quality of the statistical outputs

About the statistics

Respiratory syncytial virus (RSV) is a common respiratory pathogen that can cause serious illness in older adults, particularly those with underlying health conditions. RSV infections are often seasonal and can lead to complications such as bronchiolitis and pneumonia.

The RSV vaccine has been offered to pregnant women in England since September 2024 to address the significant burden of RSV-related illness, hospitalisations and deaths. RSV burden is particularly high among infants under 6 months of age and older adults, who are at increased risk of lower respiratory tract infection (LRTI) (1, 2). In 2023, the Joint Committee on Vaccination and Immunisation (JCVI) issued a full statement recommending the implementation of a maternal RSV vaccination programme. This recommendation was based on evidence demonstrating the safety and effectiveness of RSV vaccines in protecting infants during their most vulnerable period.

The vaccine is recommended as a year-round programme to be administered from 28 weeks of gestation onwards. This timing aligns with the optimal window for passive antibody transfer to the foetus, ensuring effective protection against severe RSV-related illness (2, 3). From 1 September 2024 (the programme start date), all women who are at least 28 weeks pregnant are advised to receive the vaccine as soon as possible, with vaccination continuing to be recommended for all eligible women throughout pregnancy up until delivery (3). The vaccine is reoffered for every subsequent pregnancy to maintain consistent coverage and protection.

The monthly maternal RSV vaccination report presents uptake data for women delivering in each month in England, based on data from general practice (GP) IT systems. The statistics are updated monthly to monitor trends in uptake and identify disparities across ethnicity and geography.

Geographical coverage: England

Publication frequency: monthly

Purpose: to monitor vaccine uptake and identify equity gaps in coverage across the eligible population

Changes to this document

5 March 2026: QMI report first published

Contact

Lead consultant: Colin Campbell

Contact information: rsv@ukhsa.gov.uk

Suitable data sources

Statistics should be based on the most appropriate data to meet intended uses.

This section describes the data used to produce the statistics.

Data sources

Maternal RSV vaccine uptake statistics are derived from GP IT systems and accessed via the ImmForm website. UKHSA determine the data to be collected on ImmForm, and specifications are developed to define the Systematised Nomenclature of Medicine (SNOMED) codes and extraction logic used to identify eligible and vaccinated individuals. Data from maternity services automatically flows into the GP record, meaning this data source captures vaccinations given across all settings.

GP-level RSV vaccine coverage data is automatically uploaded to the ImmForm website each month. This data is then validated and analysed by UKHSA to check data completeness, query any anomalous data and describe epidemiological trends.

For the maternal RSV coverage reports, coverage estimates are derived using GP-level data from ImmForm, whereas the older adult RSV reports use individual-level data from the Immunisation Information System (IIS).

This difference reflects the distinct data requirements for each programme. Although IIS provides more timely vaccination data overall, the maternal RSV report requires an accurate denominator based on the number of women delivering each month. Delivery data is sourced from maternity services which flows into the Maternity Services Data Set (MSDS). Due to the data flows involved, this delivery data is available sooner via ImmForm than through IIS.

As a result, ImmForm data is used for maternal RSV coverage reporting to ensure the most accurate and timely denominator.

Data quality

The data that we use to produce statistics must be fit for purpose. Poor quality data can cause errors and hinder effective decision making.

We have assessed the quality of the source data against the data quality dimensions in the Government Data Quality Framework.

This assessment covers the quality of the data that was used to produce the statistics, not the quality of the final statistical outputs. The quality summary section below assesses the quality of the final statistical outputs.

Strengths and limitations of the RSV data

The strengths of the data are that:

• ImmForm provides frequent, timely and accurate data to monitor the maternal RSV immunisation programme
• the methodology balances timeliness and accuracy, providing regular monthly updates while allowing sufficient time for data to flow between systems to ensure births are accurately captured
• the data is aggregated at the GP-level and stratified by ethnicity, allowing sociodemographic analyses based on GP postcode
• over 95% of GPs in England provide data for the collection
• the data specifications are defined by UKHSA, meaning cohort definitions are standardised between data suppliers and tailored to reporting requirements
• the RAVS (Record a vaccination service) point of care app, introduced in September 2023, enables vaccinations administered in maternity services to flow directly into the GP record, meaning vaccinations given across all settings are captured
• ImmForm data is routinely validated to ensure that figures are within expected ranges, and that coverage is aligned between data providers, which allows anomalies to be identified and rectified
• this methodology measures coverage in women delivering (excluding still births) by birth month which reflects the extent of passive immunity conferred to newborns
• the data is extracted automatically each month by GP IT suppliers, which minimises reporting burden on providers and ensures timely updates

The limitations of the data are that it:

• is not real-time since a 3-month reporting lag is required to allow enough time for relevant information to be recorded and for data to flow between systems
• is aggregated at the GP-level, meaning individual-level linkage and validation is not possible, which also means the residential postcode is not available for sociodemographic breakdowns
• is reliant on accurate coding of data and robust data flows between systems
• excludes individuals who are not registered with a GP
• measures coverage in women delivering (excluding still births), so it does not measure uptake across all women who were eligible in a given month

Accuracy

Accuracy refers to how well the data represents real-world conditions. This includes the correctness of details such as names and addresses, and whether the information is factual, current, and reliable

The accuracy of RSV vaccine uptake data depends on several factors, including the quality of data entry (such as clinical coding), the reliability of data flows between settings, the robustness of data specifications, and the accuracy of extraction by GP IT suppliers.

The introduction of the RAVS point of care app in September 2023 made clinical coding easier and has improved data flows between maternity services and GPs, meaning vaccination events given across all settings are captured in the GP record. While RAVs has improved the accuracy of the numerator, the denominator is reliant on the recording of delivery dates in the mother’s medical records. A recent study in England suggests that maternity notes regarding pregnancy and delivery are often scanned or archived, rather than coded in an extractable format. Furthermore, a comparison of these denominator data with national data on live births indicates that in 2022, this data represented about 73% of the population of pregnant women. While this means that some women are not captured in the ImmForm dataset, the proportion of women vaccinated is still likely to be representative of the population as a whole.

Data specifications are outlined by UKHSA and written by clinical implementation specialists to ensure cohorts are defined correctly. These specifications are periodically reviewed to ensure alignment with the most up-to-date SNOMED releases.

Once data has been extracted by GP IT suppliers, it is reviewed by the UKHSA vaccine coverage team to ensure the number of RSV vaccinations (numerator) and the number of eligible women (denominator) remain stable over time, unless there is a valid reason for the change. Regional coverage is also compared between providers to identify whether differences in coverage by provider are due to differences in geographic distribution (for example coverage for Optum being lower as they have a higher proportion of GPs in London) or systemic differences in how the providers are extracting the data.

Completeness

Completeness refers to the extent to which all expected records are present and essential fields are populated.

For the maternal RSV ImmForm collection, completeness is very high as data is extracted automatically for over 95% of GPs in England. In some cases, data from a particular GP may be suppressed due to data quality issues, as was done for the first 4 months of the maternal RSV programme.

These statistics are based on the GP record, meaning the underlying data is highly complete and all essential fields are populated.

Uniqueness

Uniqueness refers to the extent to which each record in the data set represents a distinct entity, without duplication.

In the context of the RSV vaccine programme, this means that each individual is represented by a single, unique record in the eligible population data set, and the vaccine dose administered is recorded as a singular event.

The data specifications ensure that the numerator and denominator are deduplicated and that only one vaccine event per individual is counted when calculating coverage statistics. This helps prevent inflation of uptake figures and ensures accurate cohort-level analysis. Data is also reviewed by ImmForm to ensure no duplication of reporting GPs.

Consistency

Consistency describes the degree to which values in a data set do not contradict other values representing the same entity.

The specification ensures that data is extracted consistently across GP IT suppliers. Validations are also carried out to ensure the data has been extracted correctly and is internally consistent. These validations include checking that the number of women vaccinated does not exceed the number of women delivering.

Quality assurance is also carried out to ensure consistency across the report and supplementary data tables, for example, checking that figures within the text match those in the figures and tables, and that all tables have the same total.

Timeliness

Timeliness refers to how accurately the data reflects the period it represents and whether the values are current and up to date.

Given the programme’s design, uptake is defined as the proportion of pregnant women who delivered in the reporting month and had received the RSV vaccine during pregnancy. To ensure the statistics accurately reflect uptake for a given period, the methodology uses a monthly data extraction process with a 3-month reporting lag to allow enough time for relevant information to be recorded. For example, data from September 2024 was extracted on 1 December 2024. This lag ensures the accuracy of data, while still allowing timely monitoring of the programme.

Validity

Validity refers to the extent to which data values fall within expected ranges and formats. For example, dates of birth should not exceed the current date.

These statistics are derived from GP records, which are routinely cleaned and updated. This process ensures that the underlying individual-level data used to calculate coverage figures is accurate. After coverage statistics have been extracted, the ImmForm team review the data during ingestion to ensure correct formatting. The UKHSA vaccine coverage team then review the numerator, denominator, and coverage figures to confirm they fall within expected ranges, for example, verifying that coverage does not exceed 100%.

Sound methods

Statistical outputs in this report were produced using the best available methods and recognised standards, in line with UKHSA’s approach to immunisation surveillance.

Data set production

Data used in the maternal RSV vaccine coverage report comes from the ImmForm website, which includes data from both GP IT suppliers. Flat files are downloaded via the ImmForm website for analysis.

To improve reproducibility, transparency, and efficiency, the RSV coverage reports are generated using automated workflows in R and R Markdown. This automation ensures consistency across reporting periods and enables the generation of figures, tables, and supplementary outputs directly from validated ImmForm extracts.

Quality assurance

The RSV vaccine coverage report is produced using R, with automation applied to the generation of statistics and figures. This approach reduces the risk of human error by eliminating the need for manual updates or copy-pasting between documents. Members of the UKHSA vaccine coverage team carry out quality assurance throughout the production process. Before running the automated script, the input data from ImmForm is reviewed to ensure accuracy and completeness. After the script is executed, the outputs are manually checked for anomalies or inconsistencies.

Figures and tables generated by the script are cross-checked against the narrative text in the report and compared with previous monthly reports to ensure consistency. If discrepancies or concerns are identified, further checks are conducted to determine whether the issue lies in the source data or the automation process.

This combination of automation and manual validation ensures that the RSV vaccine coverage statistics are reliable, reproducible, and fit for public health reporting.

Confidentiality and disclosure control

Personal and confidential data is collected, processed, and used in accordance with the UKHSA Privacy Notice. All UKHSA staff with access to personal or confidential information must complete mandatory information governance training, which must be refreshed every year. Information is stored on computer systems that are kept up-to-date and regularly tested to make sure they are secure and protected from viruses and hacking. UKHSA staff do not store data on their own laptops or computers, as data is stored centrally on UKHSA servers.

The ImmForm data is aggregated at the GP level, meaning no personally identifiable information is required to produce the report or supplementary data tables. In addition, disclosure control methods are in place to reduce the risk of secondary disclosure within the report or supplementary data tables. This means that if stratification of the data by geography or ethnicity results in a numerator below 5, then the data is suppressed for that group and in any associated aggregations.

Geography

UKHSA produces the statistics at 3 geographical levels:

• England
• NHS commissioning region
• NHS integrated care board

These geographic breakdowns are published in the supplementary data tables.

Quality summary

The Code of Practice for Statistics states that quality means that statistics:

• fit their intended uses
• are based on appropriate data and methods
• are not materially misleading

Producing high-quality statistics requires expert judgment throughout the process of collecting, preparing, analysing, and publishing data, ensuring that outputs are fit for purpose and meet the needs of users.

This section assesses the statistics against the European Statistical System dimensions of quality.

Relevance

Relevance is the degree to which the statistics meet user needs in both coverage and content.

These RSV coverage statistics provide essential evidence to support the monitoring and evaluation of the maternal vaccination programme in England. The statistics have been developed to reflect the structure and delivery of the programme, which targets all pregnant women, to protect infants after birth.

Regular monitoring of RSV vaccine coverage is critical for assessing the impact of the programme, identifying disparities in uptake, and informing targeted interventions. The monthly publication schedule ensures timely insights for decision makers in clinical care, public health and policy.

To meet evolving user needs and the requirements for official statistics, we have continued to seek feedback through our user survey and make changes to the publication to meet user needs.

We now publish 3 products as part of the statistical release:

• the main statistics report
• supplementary data tables
• this QMI report, published in March 2026

By providing this range of different outputs, we can better cater to the needs of different users from a range of backgrounds, in line with the Office for National Statistics user personas.

Accuracy and reliability

Accuracy refers to the closeness of a statistical estimate to the true, but unknown, value. Reliability reflects the consistency of early estimates with subsequent data releases.

For the maternal RSV programme, data is sourced from GP IT systems, via the ImmForm website. To ensure the data is accurate, the UKHSA vaccine coverage team validate the data each month prior to publication.

These validations include checking that:

• the number of women delivering each month (denominator) is within expected ranges, accounting for seasonality
• the number of vaccinations given each month (numerator) is within expected ranges and remains stable, unless there is a valid reason for the change in uptake
• the numerator and denominator for the GP IT suppliers reflect the number of GPs reporting in a given month
• coverage by region differs by less than 5% between GP IT suppliers
• the RSV denominator aligns with the denominator extracted for the prenatal pertussis ImmForm collection

Statistics are also cross-checked against other alternative data sources including IIS and MSDS to confirm alignment.

Early estimates of coverage in this population are not reliable, as it takes time for maternity data to be recorded and flow between systems. To account for this a 3-month lag is built into the schedule.

Coverage figures may be revised in future releases. For example, if data from a particular supplier was excluded from the original publication due to quality issues, we will request a re-extraction and publish updated figures once the corrected data becomes available.

Data reported prior to January 2025 only included 40.5% of GPs, meaning these figures were not as accurate as current estimates which include over 99% of GPs.

Timeliness and punctuality

Timeliness refers to the time gap between the end of the reference period and the publication of the statistics. Punctuality refers to the gap between the planned and actual publication dates.

This report aims to provide up-to-date monthly figures on RSV vaccine coverage in pregnant women to inform programme monitoring and public health decision-making in England. There is a 3-month lag to allow time for data to flow between systems, and data is published on the last Thursday of the month. This schedule means that the statistics are published 4 months after the reference period. For example, data for July 2025 was published in November 2025. This schedule allows sufficient time for the ingestion, processing, validation and quality assurance of the ImmForm data before publication in the reports.

This report is classified as official statistics and is pre-announced at least 4 weeks in advance, in accordance with the Code of Practice for Statistics.

Accessibility and clarity

Accessibility is the ease with which users can access the data, also reflecting the format in which the data is available and the availability of supporting information. Clarity refers to the quality and sufficiency of the metadata, illustrations and accompanying advice.

In the 3 statistical products, we strive to ensure compliance with the public sector body accessibility regulations and the Government Analysis Function accessibility guidance.

This report is published as HTML to ensure easy access to the report across different devices through accessibility features mentioned in the GOV.UK accessibility statement.

The publication includes visualisations that help explain the data. These are designed to be colour-blind friendly as each element has a different luminance value. This means that there is always enough contrast between elements to tell them apart.

Commentary in the publication is concise and written in plain English. We also include the main messages in the publication to help users understand the statistics.

The supplementary data tables are published in ODS format and follow the Government Analysis Function’s spreadsheet accessibility guidance. For example, each worksheet contains only one table. We also do not include nested tables with merged cells, as these do not work well with screen readers. We avoid using empty cells for the same reason. Each worksheet has a descriptive heading, for example, “Maternal RSV vaccine coverage data by Integrated Care Board, England, September 2025 to January 2026”.

Coherence and comparability

Coherence is the degree to which data that is derived from different sources or methods, but refers to the same topic, is similar. Comparability is the degree to which data can be compared over time and domain.

The maternal RSV coverage report has consistently been published from ImmForm data using standardised methodologies aligned with other UKHSA immunisation programmes, ensuring methodological coherence across monthly reports. The ImmForm data has been cross-validated against data from IIS and MSDS and shows high levels of coherence with these alternative data sources. 

Data from Optum, 1 of the 2 GP IT suppliers, was suppressed for the first 4 months of the programme, meaning data was reported for only 45% of GP practices. As a result, coverage figures for months prior to January 2025 provide an incomplete estimate and are not directly comparable with those from January 2025 onwards, which include data from over 95% of GP practices. Consequently, trends in coverage from the start of the programme can only be accurately tracked for TPP practices.

As the RSV programme matures, year-on-year comparisons will become increasingly feasible and UKHSA will continue to refine the reporting framework and ensure that supplementary data tables and statistical outputs remain coherent and comparable across reporting periods.

Maternal RSV statistics are also published by Public Health Scotland and Public Health Wales. These statistics also measure uptake of RSV in women delivering in each month, but the exact methodologies differ. For example, uptake is measured in England based on live deliveries at any gestational age, in Scotland as live deliveries reaching 28 weeks of gestation and in Wales as any delivery reaching 24 weeks of gestation. Also, in England the population is based on those registered at a GP in England, whereas in Wales the resident population is used. These differences mean that, while the figures can be used for geographical comparison, some of the observed variation may reflect methodological differences rather than genuine differences in uptake.

Uses and users

Users of statistics and data should be at the centre of statistical production, and statistics should meet user needs.

This section explains how the statistics are used, and how we understand user needs.

Appropriate use of the statistics

The statistics present RSV vaccine coverage in the England and can be used to monitor the cumulative vaccine uptake pattern and trend.

Known users and uses

We are aware that the statistics have been used by UKHSA, Department of Health and Social Care, NHS, Cabinet Office, Prime Minister’s Office, clinical professionals, the public, academia, researchers, industry professionals and media in several different ways, including:

• monitoring uptake across different regions and cohorts
• informing strategy and resource allocation
• supporting awareness campaigns
• guiding clinical decision-making
• contributing to research and evaluation
• informing national vaccine policy and programme development

User engagement

We conducted a user engagement survey in 2025 prior to the designation of these statistics as official statistics. The findings from this survey were instrumental in shaping the design and presentation of the current RSV vaccine coverage reports.

Further engagement is planned to identify additional users and understand how the statistics can be improved to better meet their needs. Insights from this future survey will inform enhancements to the April 2026 report and beyond, ensuring the statistics remain relevant, accessible, and useful to a broad range of stakeholders.

We have published supplementary tables in response to the user engagement survey, to provide uptake figures stratified by integrated care board and commissioning region.

Related statistics

Data for RSV maternal vaccination coverage in England before September 2025 is available on GOV.UK.

Surveillance of respiratory syncytial virus: winter 2024 to 2025 reports on overall RSV activity in the UK. It reports on RSV cases via surveillance, RSV-related deaths, vaccine uptake and the impact of those vaccines.

The NHS England vaccination statistics report on the number of RSV vaccinations that have been administered in England. It includes RSV vaccinations by NHS region, RSV vaccinations by cohort and RSV vaccinations by vaccination week.

Maternal RSV statistics are also published by Public Health Scotland and Public Health Wales. These statistics also measure uptake of RSV in women delivering in each month, but the exact methodologies differ. For example, uptake is measured in England based on live deliveries at any gestational age, in Scotland as live deliveries reaching 28 weeks of gestation and in Wales as any delivery reaching 24 weeks of gestation. Also, in England the population is based on those registered at a GP in England, whereas in Wales the resident population is used. These differences mean that, while the figures can be used for geographical comparison, some of the observed variation may reflect methodological differences rather than genuine differences in uptake.