Consensus statement from SPI-M-O on COVID-19. It was considered at SAGE 79 on 4 February 2021.
The paper is the assessment of the evidence at the time of writing. As new evidence or data emerges, SAGE updates its advice accordingly.
This paper contains estimates of the reproduction number (R) and growth rate for the UK, 4 nations and NHS England regions.
See the latest R number and growth rates, and further background.
Different modelling groups use different data sources to estimate these values using mathematical models that simulate the spread of infections. Some may even use all these sources of information to adjust their models to better reflect the real-world situation. There is uncertainty in all these data sources, which is why estimates can vary between different models, and why we do not rely on one model; evidence from several models is considered, discussed, combined, and the growth rate and R are then presented as ranges.
These documents are released as pre-print publications that have provided the government with rapid evidence during an emergency. These documents have not been peer-reviewed and there is no restriction on authors submitting and publishing this evidence in peer-reviewed journals.
Redactions in this document have been made to remove any security markings.