There will be no meaningful change to either the modelling or publication of this data.

UK Health Security Agency (UKHSA) will use an almost identical process to that used by SPI-M to model the R value and growth rates for England, NHS regions and the devolved administrations with individual SPI-M groups continuing to support and contribute to the modelling.

The reproduction number (R) is the average number of secondary infections produced by a single infected person, while the growth rate reflects how quickly the numbers of infections are changing day by day. Together they help scientists and the public understand the spread of the disease.

These metrics will be consolidated into UKHSA’s existing analysis to inform local and national decision making in response to coronavirus outbreaks.

SPI-M will continue to support the government as an operational subgroup of the Scientific Advisory Group for Emergencies (SAGE) and advise on infectious disease modelling and epidemiology to assist the government response to coronavirus (COVID-19) and beyond.

This will also allow many academics who have volunteered significant amounts of their own time to return to their usual research. UKHSA’s epidemiological modelling will complement the work of SAGE and support their continuing scientific work.

Dr Jenny Harries, Chief Executive of UKHSA said:

We are very grateful for SAGE and SPI-M’s enormous effort and commitment during a period of exceptional need. They have truly gone above and beyond to support the provision of robust data to the government throughout the pandemic.

It is now only right that government scientists and epidemiologists take over operational pandemic monitoring, such as assessment of the R value.

UKHSA has a wealth of experience in scientific modelling and data science. We have worked very closely with SPI-M on our modelling approach and we are pleased to be taking this on alongside our wider pandemic modelling and surveillance work, including close monitoring of the impact of easing restrictions.

Professor Graham Medley, Co-chair of SPI-M said:

The modellers on SPI-M have been supporting SAGE and UK Governments since January 2020, and I want to thank them for volunteering their time and expertise. I am pleased that we are now able to hand over the responsibility of producing R value and growth rate estimates to UKHSA.

SPI-M has worked with UKHSA closely in the past months, and will continue to do so, and we are confident that they have the knowledge and expertise to continue and develop our work.

We will continue to support the government with scientific advice in their response to COVID-19.

UKHSA will estimate R value and growth rate estimates for all 4 nations of the UK, but the devolved administrations will continue to publish estimates for their own nations. In Northern Ireland, the R value is produced by the COVID-19 modelling group on behalf of the Department of Health and Social Care.

It’s important to remember that R and growth rates are not the only important measures of the pandemic and should be considered in the context of other metrics, such as estimates of prevalence, case rates, hospitalisations and vaccinations.