SPL03 TRANSMISSION OF SARS-COV-2: FINDINGS FROM A NATIONAL CORE STUDY
Authors: Curran Andrew 
Published: July 2024

Abstract
During the SARS-CoV-2 pandemic, the UK initiated six National Core Studies to undertake targeted research activity to support the national response to the situation. One such study was designed to understand transmission of the virus, with a particular focus on workplace settings. It began in October 2020, finished in March 2023. The programme was dynamic and had to respond to changes in the pandemic situation including the immunity of the population (natural, primary-tertiary vaccination status), appearance of variants with different infection properties and changes in population behaviours. We established an active and productive research community of some two hundred scientists across nineteen organisations (University, Public Sector and commercial) to provide evidence that supported the ongoing pandemic-response including information that helped to understand and reduce transmission in a low-surveillance scenario. The researchers collected data on the environments where the virus has been encountered, the behaviour of people in those environments and the properties of the virus to enable us to understand how they combine to initiate transmission events. This enabled detailed studies of twenty outbreaks, development of quantitative risk assessment models, deep dives into specific sectors, development of new measurement techniques and the collection of data from human challenge studies. This globally unique programme showed the value of “Mission” driven programmes driving interdisciplinary benefits through the collection of real-world data. The consortium model enabled emerging findings to be compared across groups to advance knowledge at pace, and to provide direct input into policy development at different stages of the pandemic. Amongst the many findings produced by the programme were the following:
• The study showed the importance of considering the whole work-ecosystem rather than using a narrow lens of work-activity as the key risk determinant, and that every outbreak site was different.
• Physical proximity, living in deprived areas and traveling to work as a passenger were associated with increased risk of workplace outbreaks, while vaccination, and being employed with a permanent contract reduced the risk. These varied by industrial sectors.
• It was challenging for workplaces to maintain physical distancing. Ventilation was not widely understood, and many poorly ventilated areas were identified.
• The overall level of surface contamination by the virus was low.
• Most workplaces in the UK carried out site specific risk assessments and implemented multi-layered control measures.
• The programme provided a deep understanding of specific sectors: their lived experiences, learning from appropriate data sets and qualitative findings.
• Data collection from human volunteer studies showed that people don’t emit infectious virus until they are lateral flow positive, and that the amount of virus emitted is very variable.
• Only 10 infectious units is enough to infect.
More than 70 peer reviewed publications have been produced as a consequence of this work which provides a legacy of valuable knowledge for any future pandemics.