COVID-19 Briefing for 22nd June 2020

Notes from a conversation held by Lara Marks with Stephen Baker, professor of molecular microbiology, Jeffrey Cheah Biomedical Centre, Cambridge University on Friday June 12th 2020

COVID-19 screening

Over 6,000 healthcare workers have now been screened by us with Addenbrooke’s Hospital. In general it takes 18 hours and 45 minutes to turnaround results from the tests. Data from this testing has been published in NK Jones et al ‘Effective control of SARS-CoV-2 transmission between healthcare workers during a period of 2 diminished community prevalence of COVID-19’. Overall the proportion of both asymptomatic and symptomatic healthcare workers who tested positive declined to near zero between 25th April and 24th May 2020, which corresponded with a decline in patient admissions as a result of lockdown.

We are still getting a trickle of positive cases coming through. In the last couple of weeks we have had probably less than ten people test positive. There was a small cluster in one of the wards and then we had two positive cases from elsewhere. In each case the identification of the clusters enabled measures to be taken to prevent hospital transmission between staff. The screening highlighted the risk of workplace acquisition of the virus which could lead to self-sustaining outbreaks if not halted. This makes it important to keep up the screening.

The university has now decided to screen all symptomatic individuals working for the university on request. It is part of its public health measures to make sure that there is no residual infection in the university.

Serology testing

Depending on what antigen we use in the test the data suggests that the presence of antibodies may correlate with having immunity. However, we have not done enough yet to really know what that correlation looks like. So far we have not looked that in detail as we have been focusing on getting the assays working.

Addenbrooke’s Hospital is about to offer serological testing to all its staff for which we are aiming to do additional serological work and study how effectively the antibody neutralises the virus. Our intention is to work with 10,000 people and the logistics of that will be complicated which means we can’t really do the study without getting the Wellcome funding. We are still waiting to hear back from the Wellcome Trust with regards to our application. Addenbrooke's Charity is interested in supporting it so I am hopeful on that front.

There are much bigger serological studies being planned elsewhere. The question is whether the funding will be prioritised to places who can do it on a much larger scale than us with more resources. One of the difficulties is that we are really an epidemiological group. Some places for example have access to 90,000 people which we just don’t have. For us it would be an ad hoc study for a period of time. Another issue for us is that we do not have access to core funds so we can’t move quickly to do things on a scale that we would like. It's just the way science works.

Developing monoclonal antibodies and vaccine for infectious diseases

Working on COVID-19 has been good but it has been a distraction from the work I am actually paid to do. I am looking forward to having time to get on a two-year project I was about to start before we were hit by COVID-19. Some new staff have just joined which means we can soon begin working on it in earnest. The project is focusing on bacterial infectious diseases. It does not have any viral component.

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