Researchers have reported results from round nine of the REal-time Community Transmission Study (REACT-1) which assesses community prevalence of infections with severe coronavirus respiratory syndrome 2 (SARS-CoV-2 ) in England.
The SARS-CoV-2 virus is the agent responsible for the 2019 coronavirus outbreak (COVID-19) which continues to pose a threat to global public health and the global economy.
Round nine of REACT-1 took place in England in February this year (2021), approximately four to seven weeks after the implementation of the third national closure on 5th January.
Steven Riley of Imperial College London and colleagues say the results from round nine showed a significant decrease in the frequency of SARS-CoV-2, compared to at the beginning of lockout (round 8).
However, frequency remains high and the rate of decline has declined nationally in the most recent estimated period (13th to 23rd February). The study also showed that frequency has grown in some parts of the country.
The team says social pace and public health measures need to be adhered to to ensure disease rates fall to much lower levels.
“This will help ensure that the benefits of the vaccine distribution program in England are fully realized,” wrote Riley and her colleagues.
A pre-printed version of the research paper can be found on the medRxiv* server, while the article is subject to peer review.
England begin to leave the third national lock
The incidence of COVID-19 cases was high in most European countries at the beginning of 2021. The third national lockout was introduced in England on 5th January 2021, when the seven-day average number of cases was 95 per 100,000 people.
With national swab-positivity frequency for England measured using P-spline for the nine rounds with 50% posterior credit center (dark gray) and 95% (light gray). Shown here only for the period around 8 to about 9. Weightless views (black dots) and 95% binomial confidence intervals (straight lines) are also shown.
By February 22, this number had dropped to 18 per 100,000 and the seven-day average for daily hospital admissions had dropped from 3,592 to 949. More than 15 million people were also on at least one dose of Pfizer – BioNTech or Oxford – get the AstraZeneca COVID-19 Vaccine.
England start to leave the third national lock on 8th March 2021, beginning with the reopening of schools. Four additional steps follow, separated by 5-week intervals so that it is possible to assess the impact of each set of relaxation on the epilepsy.
Along with this roadmap for gradual respite, the vaccine will be rolled out against a backdrop of new variants of SARS-CoV-2.
Any increase in the incidence of disease could threaten the smooth running of the roadmap.
“Subsequent increases in the incidence of community-acquired infections could delay further lock-ins if vaccination uptake and efficacy are not high enough to prevent increased pressure on health care services,” wrote Riley and colleagues .
What was the study involved in?
REACT-1 study participants (age 5 years and older) performed a self-administered neck and nose swab for analysis with reverse transcriptase-polymerase (RT-PCR) chain reaction and completed a questionnaire on demographics , health and lifestyle.
A self-swab PCR arm (REACT-1) is designed to estimate the incidence of the SARS-CoV-2 disease community based on random cross-sections of the population.
Round nine was divided into round 9a, with swabs collected between the 4thth and 12th February, and around 9b, with swabs collected between the 13thth and 23rd February.
The results of these rounds were compared with those from round 8, where swabs were collected between the 6 roundsth and 22nd January.
Apparent percentage change in daily growth rate from round 9a to round 9b for London, measured as frequency around 9b divided by frequency around 9a divided by the difference in the median date (in days).
What did the study find?
Of 165,456 participants with a valid test result, 689 tested positive for SARS-CoV-2. Of 87,408 participants in round 9a, 388 tested positive for SARS-CoV-2 and out of 78,047 participants in round 9b, 301 tested positive.
Overall, the frequency of SARS-CoV-2 was 0.49%, representing a fall of more than two-thirds from a frequency of 1.57% in round 8.
However, the rate of decline decreased from the 15 days measured using data from the end of round 8 and the beginning of round 9, to approximately 31 days based on data from round 9 only.
The regional frequency patterns varied between rounds 8 and 9, compared with patterns seen in rounds 9a and 9b.
Between rounds 8 and 9, frequency fell sharply in seven of nine regions, with smaller waterfalls visible in Yorkshire and the Humber and the Northeast.
However, between rounds 9a and 9b, although frequency fell in the North East, North West, East and South West, increases were seen in London, the South East, the East and Central Midlands. West Midlands.
Which population groups saw a higher frequency?
The frequency fell 50% or more across all age groups in round 9, compared to round 8.
In round 9b, the frequency ranged from 0.21% among those aged 65 or older to 0.71% among those aged 13–17 years.
The frequency in round 9 was highest (2.1%) among Pakistani participants, compared to 0.45% among white participants and 0.83% among black participants.
The results also showed that health care workers and care home workers were 48% more likely to test positive in round 8 and 37% more likely in round 9, compared to staff in other professions. The number of infections was higher in each round among those working in public transport, education, school, nurseries and childcare.
“Continued vigilance required”
The researchers say that while the frequency of community swab-positivity for SARS-CoV-2 declined significantly between January and February 2021 at the time of locking in England, it remains high.
Moreover, “the rate of decline has slowed in recent times, with the growth of pockets being recommended,” they write.
“Continuous monitoring is required to ensure that the obvious benefits achieved in locking are maintained as locking measures are mitigated over the coming weeks,” concluded the team. .
* Important message
medRxiv publish preliminary scientific reports that are not peer-reviewed and, therefore, should not be seen as final, guiding health-related clinical practice / behavior, or be treated as information established.