Consensus statement from SPI-M-O on COVID-19. It was considered at SAGE 81 on 18 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 (NHSE) regions.
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.
See the latest R value and growth rates, and further background.
This paper also contains medium-term projections. These are not forecasts or predictions, and cannot reflect recent changes in transmission that have not yet filtered through into surveillance data, such as hospital admissions and deaths. With the exception of the potential impact of vaccinations, they do not account for the impact of future policy or behavioural changes that might affect transmission, nor seasonal effects that may affect transmission. They are based only on the observable trends and data available at the time the projections were produced.
Projections are particularly uncertain during periods of transition, for example when significant interventions are introduced or relaxed.
Find out more information on the medium-term projections.
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 These documents have not been peer-reviewed and there is no restriction on authors submitting and publishing this evidence in peer-reviewed journals.