Scottish Government COVID-19 Advisory Group minutes: 2 December 2021

Attendees and apologies

Advisory group members

• Andrew Morris
• David Crossman
• Linda Bauld
• Graham Ellis
• Tom Evans
• Julie Fitzpatrick
• Nick Hopkins
• Audrey MacDougall
• Jim McMenamin
• Jill Pell
• Jacqui Reilly
• Chris Robertson
• Aziz Sheikh
• Devi Sridhar
• Mark Woolhouse

Invited attendees

• Graham Foster
• Nick Phin

Scottish Government

• Mel Giarchi
• Gill Hawkins
• Daniel Kleinberg

Secretariat: [Redacted]

Items and actions

Welcome

The Chair welcomed group members and guests to the 56th meeting of the COVID-19 Advisory Group, noting that Minutes of the previous meeting had been circulated for comment prior to publication. The meeting was to discuss the developing position on Omicron but we are awaiting data and there may be a need for a longer discussion next week.

SAGE update

The Chair opened the discussion, noting that great credit was due to South African colleagues who had identified and tracked the growth of the Omicron variant and shared their knowledge quickly. The variant was likely to have developed in an immunocompromised host and was a very fit virus, which was likely to be dominant in SA by January/February.

It was now in the UK, and elsewhere, with early identification enabled by S-gene target failure. It would be important to monitor the position in South Africa but UK developments may differ due to differences in demographics and vaccinated/natural immunity. Further data was needed to scope the impacts, but there was a consensus that Omicron was potentially a serious threat to public health.

A lot would depend on how quickly we accrue cases but Scottish data over the last week already showing a significant increase in S-gene target failure, suggesting exponential growth, albeit starting from low levels. Possibly there was ascertainment bias and future growth remains to be seen.

The epidemiological data from South Africa shows a rate of spread that is phenomenal. Omicron is more transmissible than Delta and could cause a large spike in cases, replacing Delta within weeks in the UK and Europe if we follow the same pattern. The effect on hospitalisation is uncertain as we have no reliable data on pathogenicity of Omicron or the effect of boosters. There is however the potential for another bad wave with more patients in hospital. Early intervention could avoid harsher measures later; two weeks is a very long time with a high doubling rate but the most effective action will be clearer when we know more.

Indications of doubling times across Scotland is heterogeneous, with doubling times of two or three days in places. This would match South Africa for speed, though more data is needed. Previous projections based on Delta would underestimate the probable effect of Omicron as its Rt is much higher than what we have modelled to date.

We also need data on impact on morbidity and mortality. Scottish cases so far are split between symptomatic and asymptomatic, with no serious infections though cases are from younger age groups. Omicron will probably take over from Delta very quickly but pathogenicity will in part determine how bad the next wave will be. Even if it were to be less severe, a spike of Omicron cases is likely to show an increase in hospitalisations

One of the issues in South Africa has been reinfections, including under 90 days. Scottish data doesn’t show that, so far, but very low numbers and need much more data to reach any conclusions on the importance of vaccination status and boosters on hospitalisation and transmission. Experience so far is that S gene dropout is a good indicator for Omicron; monitoring those cases will give us some early warning of transmission, pending confirmation via sequencing.

We will need data on around 1,000 cases at UK level to get a useful estimate of hospitalisation. Cases are mostly travel linked but also secondary & tertiary. The secondary attack rate appears higher than expected. The early data is concerning but it will take time to get to any level of confidence.

Evidence of transmissibility likely to be a property of immune escape. Evidence is needed on the impact of Omicron on T cells - we don’t know the degree of vaccine escape with high levels of antibody levels post-booster but maximising primary courses and boosters should continue to be a priority.

Exponential growth is explosive, though until we know about severity a range of outcomes is possible. There is a sharp differentiation in outcomes between older and younger cases, though much improved from a year ago, with even older vaccinated people recovering – the media focus on underlying health conditions is distorted. We are looking at a substantial wave with the NHS also hit by winter pressures and the prospect of nurses and other staff absent. What we have learned from previous waves is that home working may be a quick win. Travel regulations may slow but not stop the spread of Omicron in the early stages but, when community transmission takes hold, cease to be a necessary measure.

There is some scope for optimism that boosters will reduce severe disease. Also positive that all the things we would do to prevent a fourth wave would also reduce Delta, including self testing. Home working will help, but Christmas mixing is an issue. Antiviral treatments could be a way to help manage this but are not in themselves a solution. Need to be clear that including schools within any restrictions could have a significant harm three impact.

Summarising the discussion, the Chair noted the following:

• sense of urgency
• difficult decisions, the importance of being proportionate in the face of uncertainty
• likely substantial wave
• cases already seen in Scotland
• short doubling time seen in early Scottish data
• pathogenicity uncertain and may need 1000 cases to have more conclusive on this
• reinfection within 90 days is unsurprising if it is mucosal infection. Unclear if this translates to significant disease
• need laboratory studies on immune response
• pressure on education, business and healthcare workforce
• harm 3 impacts, notably of any changes to policy around schools
• ‘go early’ – vaccinate, home working, handwashing and regular testing to be encouraged. Impact of travel regulations is likely to be trivial shortly. Booster vaccinations and the very high levels of response they produce may allow us to outrun this, depending on the level of immune escape
• need to be clear about exit strategy if restrictions brought in. Is long term plan to wait for new vaccine or increase use of antivirals (noting antivirals are not in themselves a solution due to risk of resistance)
• reasonable Worst Case Scenario – the group noted that the London School of Hygiene and Tropical Medicine is already modelling

AOB

The group will meet again next week, to discuss the read out from SAGE on 7 December. There will be a further SAGE meeting the following week and a meeting is already arranged for 17 December.