Background
In England, hospitalisations and deaths due to SARS-CoV-2 have been falling consistently
since January 2021 during the third national lockdown of the COVID-19 pandemic. The first
significant relaxation of that lockdown occurred on 8 March when schools reopened.
Methods
The REal-time Assessment of Community Transmission-1 (REACT-1) study augments
routine surveillance data for England by measuring swab-positivity for SARS-CoV-2 in the
community. The current round, round 10, collected swabs from 11 to 30 March 2021 and is
compared here to round 9, in which swabs were collected from 4 to 23 February 2021.
Results
During round 10, we estimated an R number of 1.00 (95% confidence interval 0.81, 1.21).
Between rounds 9 and 10 we estimated national prevalence has dropped by ~60% from
0.49% (0.44%, 0.55%) in February to 0.20% (0.17%, 0.23%) in March. There were
substantial falls in weighted regional prevalence: in South East from 0.36% (0.29%, 0.44%)
in round 9 to 0.07% (0.04%, 0.12%) in round 10; London from 0.60% (0.48%, 0.76%) to
0.16% (0.10%, 0.26%); East of England from 0.47% (0.36%, 0.60%) to 0.15% (0.10%,
0.24%); East Midlands from 0.59% (0.45%, 0.77%) to 0.19% (0.13%, 0.28%); and North
West from 0.69% (0.54%, 0.88%) to 0.31% (0.21%, 0.45%). Areas of apparent higher
prevalence remain in parts of the North West, and Yorkshire and The Humber. The highest
prevalence in March was found among school-aged children 5 to 12 years at 0.41% (0.27%,
0.62%), compared with the lowest in those aged 65 to 74 and 75 and over at 0.09% (0.05%,
0.16%). The close approximation between prevalence of infections and deaths (suitably
lagged) is diverging, suggesting that infections may have resulted in fewer hospitalisations
and deaths since the start of widespread vaccination.
Conclusion
We report a sharp decline in prevalence of infections between February and March 2021.
We did not observe an increase in the prevalence of SARS-CoV-2 following the reopening of
schools in England, although the decline of prevalence appears to have stopped. Future
rounds of REACT-1 will be able to measure the rate of growth or decline from this current
plateau and hence help assess the effectiveness of the vaccination roll-out on transmission
of the virus as well as the potential size of any third wave during the ensuing months.