SARS-CoV-2 WW transmission: Report for SAGE 08/04/202123 Apr 2021 21:05
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Current environmental monitoring cannot constrain the effect of vaccines on
SARS-CoV-2 transmission: Report for SAGE 08/04/2021
Applications and future directions
While the current predictive ability of wastewater-based surveillance is promising, expanding these
models to include temporal structure and use information from multiple samples (such as distributed lag
models) is likely to increase the predictive performance. Explicitly modelling prediction errors will
continue to highlight areas of improvement for the EMHP wastewater surveillance programme. For
example, laboratory methods are being considered to lower the limit of quantification and detection and
new approaches to sample collection are being explored to reduce noise. Hierarchical modelling
approaches will facilitate integrating new sites into the national surveillance programme to expand the
population coverage of WBE and aid monitoring of public health beyond COVID-19. The value of
mechanistic (or process-based) modelling in supporting the study and management of environmentrelated health issues is increasingly recognised (Beltrame et al., 2021), and opportunities for using
mechanistic modelling in wastewater-based epidemiology are also being explored. Mechanistic modelling
could complement statistical models by providing a rationale for the nature of the relation between
prevalence and concentrations of the virus in wastewater. It could also help explain the noise in the data
over time, as well as variability between sites. Identifying where the data conflict with process-based
estimates could highlight opportunities for improving the collection and processing of data. Comparing
process-based estimates of prevalence from wastewater data under different assumptions
(vaccination/no vaccination, different NPIs) could be an alternative way of exploring the influence of these
interventions.
While WBE has been of limited use in assessing the impact of vaccines on SARS-CoV-2 transmission, the
EMHP programme has provided insight into areas of stubborn transmission, increasing prevalence of
SARS-CoV-2, community transmission of VOC/VUIs, and infection trends in settings including prisons and
schools. These insights have aided local and national teams in planning and responding to COVID-19, and
we will continue to expand on the operational use cases detailed in Wade et al., 2020 and Brown et al.,
2021 as WBE analytical capabilities and capacity develop further.