REACT-1 round 12 report: resurgence of SARS-CoV-2 infections in England associated with increased frequency of the Delta variant

Abstract

Background England entered a third national lockdown from 6 January 2021 due to the COVID-19 pandemic. Despite a successful vaccine rollout during the first half of 2021, cases and hospitalisations have started to increase since the end of May as the SARS-CoV-2 Delta (B.1.617.2) variant increases in frequency. The final step of relaxation of COVID-19 restrictions in England has been delayed from 21 June to 19 July 2021. Methods The REal-time Assessment of Community Transmision-1 (REACT-1) study measures the prevalence of swab-positivity among random samples of the population of England. Round 12 of REACT-1 obtained self-administered swab collections from participants from 20 May 2021 to 7 June 2021; results are compared with those for round 11, in which swabs were collected from 15 April to 3 May 2021. Results Between rounds 11 and 12, national prevalence increased from 0.10% (0.08%, 0.13%) to 0.15% (0.12%, 0.18%). During round 12, we detected exponential growth with a doubling time of 11 (7.1, 23) days and an R number of 1.44 (1.20, 1.73). The highest prevalence was found in the North West at 0.26% (0.16%, 0.41%) compared to 0.05% (0.02%, 0.12%) in the South West. In the North West, the locations of positive samples suggested a cluster in Greater Manchester and the east Lancashire area. Prevalence in those aged 5-49 was 2.5 times higher at 0.20% (0.16%, 0.26%) compared with those aged 50 years and above at 0.08% (0.06%, 0.11%). At the beginning of February 2021, the link between infection rates and hospitalisations and deaths started to weaken, although in late April 2021, infection rates and hospital admissions started to reconverge. When split by age, the weakened link between infection rates and hospitalisations at ages 65 years and above was maintained, while the trends converged below the age of 65 years. The majority of the infections in the younger group occurred in the unvaccinated population or those without a stated vaccine history. We observed the rapid replacement of the Alpha (B.1.1.7) variant of SARS-CoV-2 with the Delta variant during the period covered by rounds 11 and 12 of the study. Discussion The extent to which exponential growth continues, or slows down as a consequence of the continued rapid roll-out of the vaccination programme, including to young adults, requires close monitoring. Data on community prevalence are vital to track the course of the epidemic and inform ongoing decisions about the timing of further lifting of restrictions in England.

The Relationship Between the COVID-19 Pandemic and Vaccine Hesitancy: A Scoping Review of Literature Until August 2021

“…While evidence points toward lower COVID-19 mortality rates in children, they still account for a sizeable proportion of COVID-19 cases (27). In fact, according to a preprint containing data from the UK, children and adults under 50 may be up to 2.5 times more likely to be infected with the surging Delta variant (28). Data from Taiwan further shows that ∼50% of children infected with COVID-19 still retain symptoms half a year after (29).…”

Characterising the persistence of RT-PCR positivity and incidence in a community survey of SARS-CoV-2

“…Finally we indicate that Alpha variant infections may have a greater median duration of positivity than wildtype, similar to other work [6], though with wide credible intervals. With the recent emergence of the Delta variant [15] in England, characterising any possible changes in RT-PCR test sensitivity and duration of positivity will be necessary to estimate infection incidence of Delta from swab-positivity data.…”

Sentiments Regarding COVID-19 Vaccination among Graduate Students in Singapore

“…This would account for more 'unsure' but less 'no' to vaccination in our survey. With the new, more infectious delta variant raging in the world recently that was reported to also affect the younger population [51,52], it would be worthwhile to evaluate whether the sentiments of these same students in Singapore towards vaccination have changed with the current fluctuating community spread in Singapore.…”