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Coronavirus (COVID-19): state of the epidemic - 15 October 2021

This report brings together the different sources of evidence and data about the Covid epidemic to summarise the current situation, why we are at that place, and what is likely to happen next.

Coronavirus (COVID-19): state of the epidemic - 15 October 2021
State of the Epidemic in Scotland – 15 October 2021

State of the Epidemic in Scotland – 15 October 2021

Background

This report summarises the current situation on the Covid-19 epidemic in Scotland. It brings together the different sources of evidence and data about the epidemic in Scotland at this point in time, why we are at that place, and what is likely to happen next. This summarises the data up to and including 14 October 2021 on Covid-19 in Scotland. This updates the previous publication published on 8 October[1]. The information in this document helps the Scottish Government, the health service and the wider public sector respond to the epidemic and put in place what is needed to keep us safe and treat people who have the virus.

This edition of the State of the Epidemic summarises current data on Covid-19 at a national and local level, and how Scotland currently compares to the rest of the UK. It looks at the vaccination program in Scotland and its impact. Information is provided about variants of concern and what impact these may have. Bringing this information together in one place gives the opportunity to better understand the current state of the epidemic in Scotland.

Key Points

  • The reproduction rate R in Scotland, as of 28 September, is estimated as being between 0.8 and 1.0. The lower limit has increased since last week.
  • An average of 2,405 cases were reported per day in the 7 days to 14 October. This is similar to average cases (2,401) on 7 October.
  • There were 312 weekly cases per 100,000 in the week to 11 October (by specimen date). This is lower than the most recent peak (825 weekly cases per 100,000 on 6 September) and lower than the peak in July (425 weekly cases per 100,000 recorded on 3 July). There are early signs that 7 day case rates may be fluctuating or levelling off.
  • Case rates also appear to be fluctuating or levelling off across all age bands in the week to 11 October. As of 11 October, the highest case rates were observed amongst under 20s, followed by 40-59, 20-39, 60-79 and 80+.
  • As determined through the latest weekly ONS survey, the estimated proportion of population living in private residential households testing positive for SARS-CoV-2 in Scotland has continued to decrease in the last week (week ending 9 October 2021).
  • Latest modelled estimates suggest that as of 21 September there were between 94 and 142 new daily infections per 100,000 people in Scotland. This is a decrease in the lower and upper limits since last week.
  • There were 126 deaths registered in Scotland where coronavirus was mentioned on the death certificate in the week ending 10 October.
  • Average hospital admissions (3-week rolling average) related to Covid-19 in children have decreased in most age groups compared to the previous three-week period.
  • Stirling currently has the highest weekly case rate in Scotland reporting 471 weekly cases per 100,000 in the week to 11 October, followed by West Lothian with 441 weekly cases per 100,000, and Dundee with 437 weekly cases per 100,000 population. All local authorities reported over 100 weekly cases per 100,000 population in the last week, except for Orkney. Orkney reported the lowest case rate with 71 weekly cases per 100,000 in the same period.
  • Nationwide, after a recent plateau, levels of Covid-19 in wastewater resumed falling this week, down around 40% from last week. Reductions in sampled levels at the major cities drove this decrease, though there remain high amounts of variability.
  • Hospital and ICU occupancies have plateaued, and are falling slowly. There continues to be uncertainty over hospital occupancy and intensive care in the next three weeks.
  • Over 4.2 million people in Scotland have been given a first vaccine against SARS-CoV-2, almost 3.9 million have received a second dose, and over 240,000 people have received a booster dose by 14 October.
  • The Delta variant remains the dominant strain in Scotland.

Method

This report brings together a wide range of publically available figures from a range of data sources. These include publications by Scottish Government, Public Heath Scotland, National Records of Scotland and Office for National Statistics along with scientific publications and SAGE and UKHSA summaries where appropriate to summarise the state of the epidemic in Scotland in a given week. We also provide information on public attitudes to the virus from weekly YouGov polling surveys.

The national picture

The latest R value for Scotland, as of 28 September (published on 14 October and using data to 11 October)[2], was between 0.8 and 1.0 (Figure 1), with a growth rate of between -3% and 0%. The lower limit of R value has increased since last week.

Figure 1: R in Scotland over time
This column chart shows the estimated range of R over time, from early September 2020. The R number has varied over the pandemic with the estimated range moving above 1 in Autumn 2020, January 2021, June 2021 and again at the end of August 2021. 
The latest R value for Scotland is estimated to be between 0.8 to 1.0. The lower limit has increased since last week.

An average of 2,405 cases were reported per day in the 7 days to 14 October. This is similar to the daily average cases (2,401) recorded a week earlier on 7 October[3]. In the week 2-8 October 2021, there were 411 cases (PCR testing only) per 100,000 amongst the unvaccinated individuals, compared to 231 cases per 100,000 for those that had been vaccinated with two doses[4]. Our current position is 312 weekly cases per 100,000 in the week to 11 October (by specimen date)[5]. This is lower than the most recent peak of 825 weekly cases per 100,000 on 6 September and lower than the previous peak of 425 weekly cases recorded on 3 July (see Figure 2). There are early signs that 7 day case rates may be fluctuating or levelling off.

The number of locations where the levels of SARS-CoV-2 in wastewater are monitored has increased to 110 sites around Scotland. In contrast to Covid-19 case records, virus shedding into wastewater is a biological process. This means that wastewater data is unaffected by factors that impact whether testing is done. Nationwide, after a recent plateau, levels of Covid-19 in wastewater resumed falling this week, down around 40% from last week. Reductions in sampled levels at the major cities drove this decrease, though there remain high amounts of variability.

Figure 2: Seven day case rate for Scotland by specimen date. Refers to PCR testing only.
This line graph shows weekly cases per 100,000 people over time, from mid-September 2020. The case rate rose from a low of 25 in September to 170 in October 2020. It then reduced to just over 100 by the beginning of December 2020. At the end of December it rose sharply to just over 300 at the start of January 2021 which then continued to decrease until mid-May.  
There has been a sharp increase in case rates from mid-May to beginning of July 2021 followed by a sharp decline. Case rates started to increase again at the beginning of August 2021 and surpassed the peak seen at the start of July 2021. Case rates reached the peak on 6 September and started to go down since then. It is now lower than the peak of July, with just over 300 weekly cases per 100,000 population registered at the start of October. Case rates have been fluctuating or levelling off over the last week.

Case rates have been fluctuating or levelling off across all age bands in the week to 11 October. As of 11 October, the highest case rates were observed amongst under 20s, followed by 40-59, 20-39, 60-79 and 80+ (Figure 3).

Figure 3: Seven day case rate in Scotland by age group by specimen date [6]. Refers to PCR testing only.
This line graph shows weekly cases per 100,000 people for five different age bands over time, from mid-September 2020. Each age band shows a similar trend with a peak in cases in January, with the 20 to 39 age band having the highest case rate, and the under 20 age band having the lowest case rate. Case rates reduced in all age groups from this peak and then started to increase again sharply from mid-May, reaching a peak at the beginning of July 2021. 7 day case rates per 100,000 population then started to decrease sharply followed by a sharp increase in cases in mid-August 2021. Case rates started to go down at the start of September for all age groups. Case rates have been fluctuating or levelling off across all age bands over the last week.

Not everyone who has the virus will be tested, as many people do not realise they have Covid-19, or they have mild symptoms and do not come forward. Latest modelled estimates suggest that, as at 28 September, the incidence of new daily infections in Scotland was between 94 and 142 new infections per 100,000[7]. This equates to between 5,100 and 7,800 people becoming infected each day in Scotland. This is a decrease in the lower and upper limits since last week.

Hospital and ICU occupancies appear to be fluctuating up and down and may be declining slowly. The number of people in hospital with confirmed Covid-19 for less than 28 days peaked at 2,053 on 22 January and decreased to a low of 58 on 6 May[8]. This has since increased and as of 14 October there were 908 patients in hospital with Covid-19. This compares to 980 people in hospital on 7 October (Figure 4). The latest data from PHS shows 629 admissions to hospital for people with confirmed Covid-19 in the week to 10 October compared to 646 in the week to 3 October[9]. In the 4 weeks to 8 October 30.7% of acute Covid-19 hospital admissions were in unvaccinated individuals[10]. For context, as of 14 October, 92.2% of adults aged 18+ (91.7% of adults aged 16+) have had at least one dose of the vaccine. Overall, individuals in the oldest age groups were most likely to be hospitalised. In all age groups, the rate of admissions per 100,000 was higher in unvaccinated individuals compared to fully vaccinated individuals in the week to 8 October. Unvaccinated individuals were 1.8 to 4 times more likely to be in hospital with Covid-19 compared to fully vaccinated individuals (depending on age) in the period 2-8 October[11].

As the population is increasingly vaccinated, more of the patients in hospital will be fully or partially vaccinated. Therefore, it is important that we can differentiate between patients in hospital because of Covid-19 rather than with Covid-19. Public Health Scotland estimates that as at June 2021 72% of acute hospital admissions have a primary diagnosis of Covid-19. The trend has been decreasing since January 2021, and has fluctuated between 66% and 78%[12].

Figure 4: Patients in hospital (including those in ICU) (with length of stay 28 days or less) and ICU [13] with recently confirmed Covid-19
This line chart shows the daily number of patients in hospital and ICU (or combined ICU/ HDU) across Scotland with recently confirmed Covid-19 with a length of stay of 28 days or less since 11 September 2020. Covid-19 patients in hospital (including those in ICU) increased sharply from the end-September 2020 reaching a peak at the beginning of November. Patients in hospital then stabilised before a decrease at the beginning of December. It then started rising sharply from the end of December, reaching a peak of over 2,000 on 22 January. The number of patients in hospital decreased sharply since then before plateauing throughout May and June. It then rose to over 500 patients in hospital in July and decreased by the end of August. It then rose again reaching a peak of over a 1,000 patients in hospital by mid-September. Since then, hospital occupancy has been fluctuating up and down but appears to be slowly declining.
A line for patients in ICU follows a similar pattern with an increase seen from end-September 2020. It then reached a peak of over 100 patients in ICU with length of stay 28 days or less at the beginning of November and then decreased to just below 50 patients in ICU in December 2020. Then a sharper increase is seen in patients in ICU by the end of January before it started to decrease. The number of patients in ICU remained low throughout late spring and early summer before a slight increase in July. It then decreased a little before a further increase by mid-September. Since then, ICU occupancy has been fluctuating up and down but appears to be slowly declining.

There were 126 deaths registered where Covid-19 was mentioned on the death certificate in the week to 10 October. This is a decrease of 17 (-12%) in the number of deaths from the previous week, and 81% lower than the peak in April 2020 (663 deaths). The proportion of deaths in care homes decreased from 60% in April 2020 to 15% in the week to 10 October, with 19 deaths occurring in care homes[14]. In the week ending 10 October, deaths involving coronavirus have increased in those aged 45-64 (from 21 to 24 deaths) and 75-84 (from 32 to 34 deaths) compared to week ending 19 September. Deaths decreased in those aged 15-44 (from 3 to 2 deaths) and those aged 65-74 (from 37 to 24 deaths), and remained unchanged for adults aged 85+ (42 deaths). Deaths remained at 0 in those aged under 15 in the same period[15] (Figure 5). From 29 December 2020 to 1 October 2021, 76.8% of Covid-19 deaths were in unvaccinated individuals[16]. Amongst those individuals who have been vaccinated with two doses of Covid-19 vaccine, 80.3% of the confirmed Covid-19 deaths occurred in the 70+ age group[17].

Figure 5: Deaths by age group (weekly total by week beginning, NRS) 12
This line graph shows the weekly number of deaths for seven different age groups over time, from March 2020. In April 2020 the number of deaths in the four age groups over 45 reached a peak, with the highest number of deaths being in the over 85 age group. Deaths then declined steeply and the number of deaths was very low in all age groups from July to September 2020. In October the number of deaths started to increase and then plateaued during November and December 2020 for the four age groups over 45. At the end of December deaths rose steeply again to another peak in January 2021, with the highest deaths being in the over 85 age group. The number of deaths has since declined steeply with the largest decrease in the over 85 age group, followed by a sharp decline in the 75 to 84 age group. Since mid-June 2021 there has been a slight increase in deaths overall, with the greatest increase in the 45 plus age groups. However, the number of deaths in all age groups remained low with only a slight recent increase seen with 126 deaths registered over the latest week. Deaths in the under 44 age groups have remained very low throughout the whole period.

How Scotland compares with the rest of the UK

The ONS Covid-19 Infection Survey estimates that in the week 3 to 9 October 2021 the estimated percentage of the population living in private residential households testing positive for Covid-19 in Scotland was 1.26% (95% credible interval: 1.02% to 1.54%). The percentage of people testing positive for Covid-19 in the private residential population has continued to decrease in the most recent week. Estimates for the same week in the other UK nations are as follows: 1.63% (95% credible interval: 1.54% to 1.73%) for England, 2.18% (95% credible interval: 1.79% to 2.61%) for Wales and 0.82% (95% credible interval: 0.53% to 1.18%) for Northern Ireland. This equates to around 1 in 80 people in Scotland, 1 in 60 in England, 1 in 45 in Wales and 1 in 120 in Northern Ireland[18].

The ONS Covid-19 Infection Survey estimated that in the week beginning 23 August 2021, 93.3% (95% CI: 91.9% to 94.4%) of the adult population living in private residential households in Scotland would have tested positive for antibodies against SARS-CoV-2, as a result of having the infection in the past or being vaccinated. This compares to 93.6% in England (95% CI: 92.5% to 94.5%), 91.2% in Wales (95% CI: 89.5% to 92.7%) and 91.9% in Northern Ireland (95% CI: 88.4% to 94.0%)[19].

An estimated 1.7% of the population living in private residential households in the UK were experiencing self-reported long Covid symptoms (symptoms persisting for more than four weeks after the first suspected coronavirus (Covid-19) infection that were not explained by something else) in the 4 weeks ending 5 September 2021. In Scotland, 79,000 people (1.5% of the respective population) living in private households self-reported long Covid symptoms for this period. This compares to 1.73% in England, 1.38% in Wales and 1.03% in Northern Ireland[20].

Average daily deaths in Scotland (3 per 1 million population) in the week to 14 October are above England, Wales and Northern Ireland (2 per 1 million each)[21]. Average daily cases in Scotland (440 per 1 million) in the week to 14 October are below Wales (772 per 1 million), Northern Ireland (665 per 1 million) and England (594 per 1 million)[22].

Situation by local authority within Scotland

Stirling currently has the highest weekly case rate in Scotland reporting 471 weekly cases per 100,000 in the week to 11 October, followed by West Lothian with 441 weekly cases per 100,000, Dundee City with 437 weekly cases per 100,000, Fife with 395 weekly cases per 100,000, Aberdeenshire with 389 weekly cases per 100,000 and East Renfrewshire with 388 weekly cases per 100,000 population. All local authorities reported over 100 weekly cases per 100,000 population in the last week, except for Orkney (Table 1). Case rates have decreased in Aberdeen, Dumfries and Galloway, East Dunbartonshire, Falkirk, Glasgow, Midlothian, Moray, Na h-Eileanan Siar, North Lanarkshire, Renfrewshire, Shetland Islands, South Ayrshire, South Lanarkshire, West Dunbartonshire and West Lothian over the last week. However, there are still very high levels (150+ weekly cases per 100,000) of case rates across Scotland (Figure 6). Orkney has the lowest case rate in Scotland, reporting 71 weekly cases per 100,000 in the week to 11 October[23].

Table 1: Total new weekly cases per 100,000 population to 11 October 2021, in order of prevalence
Local authority Total new cases in the week, per 100,000 population Change since previous week
Stirling 471 114
West Lothian 441 -27
Dundee City 437 40
Fife 395 44
Aberdeenshire 389 30
East Renfrewshire 388 30
East Ayrshire 378 1
Falkirk 366 -18
North Ayrshire 361 25
North Lanarkshire 355 -58
Moray 330 -6
Scottish Borders 323 49
South Lanarkshire 319 -41
Renfrewshire 309 -2
West Dunbartonshire 307 -44
Clackmannanshire 304 39
Angus 301 90
East Lothian 292 78
East Dunbartonshire 291 -78
Perth and Kinross 289 38
Dumfries and Galloway 276 -36
Inverclyde 256 22
Glasgow City 255 -44
Aberdeen City 255 -26
Argyll and Bute 249 4
Midlothian 247 -15
City of Edinburgh 245 49
South Ayrshire 245 -63
Highland 216 46
Na h-Eileanan Siar 125 -121
Shetland Islands 114 -4
Orkney Islands 71 9
Scotland 312 3
Figure 6: Map of weekly new positive cases per 100,000 people in Scotland
This colour coded map of Scotland shows the different rates of weekly positive cases per 100,000 people across Scotland’s Local Authorities. The colours range from grey for under 50 weekly cases per 100,000, through very light orange for 50 to 100, orange for 100-300, darker orange for 300-500, and very dark orange for over 500 weekly cases per 100,000 people. 
No local authorities are showing as very dark orange on the map this week, with over 500 weekly cases, and no local authorities are showing as grey for under 50 weekly cases per 100,000. Orkney is shown as very light orange, with 50-100 weekly cases per 100,000 people. Aberdeen, Argyll and Bute, Edinburgh, Dumfries and Galloway, East Dunbartonshire, East Lothian, Glasgow, Highland, Inverclyde, Midlothian, Na h-Eileanan Siar, Perth and Kinross, Shetland and South Ayrshire are showing as orange with 100-300 weekly cases. All other local authorities are shown as darker orange with 300-500 weekly cases per 100,000.

The most recent modelling predicts, based on data up to 11 October, that for the week commencing 24 October 2021, there are 29 local authorities which are expected to exceed 50 cases per 100,000 population with at least 75% probability. Dundee is the only local authority which is expected to exceed 300 cases per 100,000 population with at least 75% probability, and there are no local authorities which are expected to exceed 500 cases per 100,000 with at least 75% probability[24].

Children and Education

Schools resumed in Scotland by the week ending 20 August and most universities resumed by end of September. The majority of children and young people have returned to full time education. However, throughout October, schools will be on holiday, with term times varying across Scotland. This may have an effect on testing.

Over the last week there was a decrease in the total number of Covid-19 cases in young people aged under 22, which has decreased from 6,403 cases in the week to 3 October to 6,199 cases in the week ending 10 October. 7 day case rates per 100,000 have also have continued to decrease or have plateaued in all age groups, except for 5-11 year olds, in the week ending 10 October (Figure 7). The percentage of cases made up of children under 12 was just under 57% (3,516 cases) in the week to 10 October compared to just under 53% (3,383 cases) in the previous week[25]. The percentage of cases made up of 18-21 year olds was 6% (396 cases) in the week to 10 October compared to 7% (458 cases) in the week ending 3 October. Following the return of universities, there is no evidence of an uptick in cases in the 18-21 year age group.

The rate of testing decreased amongst all age groups in the week ending 10 October. Test positivity rates have increased in all age groups, except for 16-19 year olds, in the same period. In the week ending 10 October, the proportion of positive cases who report having been in an education setting in the 7 day period prior to the onset of symptoms has slightly increased to 21.2% compared to 20.6% in the week ending 3 October. Hospital admissions (3 week rolling average) in children and young adults decreased amongst all age groups, except for 2-4 year olds, in the period 16 September – 6 October compared to the previous three-week period (9-29 September).

Vaccine uptake in 17-21 year olds as at 11 October was 78.4% for the first dose and 57.3 for the second dose[26]. Please note that under half of Scottish students are in this age category and only Scottish students (i.e. registered with a GP in Scotland) are included in the figures. Covid-19 infection survey estimated that up to the week beginning 23 August 2021, the percentage of 16-24 year olds in the community population in Scotland testing positive for antibodies increased to 88.7%[27].

Figure 7: Seven day case rate in Scotland by age group by specimen date for children and young people (week ending 10 October). Refers to PCR testing only.
This figure shows the 7-day case rate of school pupils and younger adults of under 22 years of age who tested positive for Covid-19, grouped in seven age groups, during the period 14 February 2021 to 10 October 2021. Markers also show all Scotland case rate for comparison.
The rates for all age groups have varied over time. Case rates remained relatively low from mid-February to May. They then started to increase in May and peaked in early July, with the highest case rate among 18-19 year olds. The rates decreased across all age groups in late July. Case rates then started to rise at the beginning of August 2021, reaching the peak early September. These then started to go down. In the latest week ending 10 October, the 7 day case rates declined in all age groups, except for 5-11 year olds.

Looking ahead

Changes in patterns of mixing and adherence to restrictions will impact on future case numbers. The Scottish Contact Survey measures times and settings that people mix where they could potentially spread Covid-19.

Average contacts have decreased by 7% in the last two weeks (comparing surveys pertaining to 16 September - 22 September and 30 September - 6 October) with a current level of 4.6 daily contacts.

Mean contacts within the home have increased by 9% whereas contacts in the other setting (contacts outside home, school or work) have decreased by 22% in the last two weeks. Contacts within the work setting have remained at a similar level over the same period.

Those aged between 30-59 reported an increase in overall contacts whereas all remaining age groups reported a decrease, with those aged 18-29 reducing by half in the last two weeks. The decrease within the 18-29 is largely driven by a drop in contacts within the work setting.

The proportion of individuals visiting a healthcare facility increased from approximately 17% to 23% with individuals visiting a pub or restaurant decreasing from 49% to 47% in the last two weeks.

Self-reported compliance with the current regulations and guidance has decreased since January but remains at a high level. On 5-6 October, 70% of people reported ‘complete’ or ‘almost complete’ compliance[28].

Hospital and ICU occupancies have plateaued, and are falling slowly. There continues to be uncertainty over hospital occupancy and intensive care in the next three weeks (Figure 8)[29].

Figure 8: Medium term projections of modelled hospital bed demand, from Scottish Government modelling [30]
This line graph shows projected demand for hospital beds over time from mid-September to start November 2021, and includes three scenarios; ‘better’, ‘central’ and ‘worse’. Markers also show the actual number of hospital beds that were required until start October. Based on the recent changes in cases, hospital beds are projected to decrease in ‘better’, increase in ‘worse’ and plateau in ‘central’ scenarios.

Vaccinations are continuing across the priority groups and 91.7% of the 16+ population in Scotland has now been vaccinated with the first dose[31]. The first vaccines were administered on Tuesday 8 December and 4,275,238 people had received their first dose by 14 October 2021[32]. By age group, almost 100% of individuals aged 55+, 97% of those aged 50-54, 92% of those aged 40-49, 84% of those aged 30-39, 77% of those aged 18-29, 73% of those aged 16-17 and 43% of those aged 12-15 have received their first vaccination (Figure 9).

Almost 100% of individuals aged 60+, 97% of those aged 55-59, 94% of those aged 50-54, 87% of those aged 40-49, 76% of those aged 30-39, 65% of those aged 18-29, 13% of those aged 16-17 and 0% of those aged 12-15 have received their second dose. Overall, 3,871,453 people (85.1% of those aged 16 and over) had received their second dose and 240,456 people have received their booster vaccine by 14 October[33]. There remains a low level of deaths amongst the vaccinated individuals (Figure 5).

Figure 9: Estimated percentage of adults vaccinated by 14 October 2021
This bar chart shows the percentage of people that have received their first and second dose of the Covid vaccine so far, for twelve age groups. The six groups aged over 55 have more than 99% of people vaccinated with the first dose and more than 97% of people vaccinated with the second dose. Of those aged 50-54, 97% have received their first dose and 94% have received their second dose. Younger age groups have lower percentages vaccinated, with 92% of 40-49 year olds having received their first dose and 87% the second dose, 84% of the 30-39 year olds having received their first and 76% having received their second dose, 77% of 18 to 29 year olds having received the first dose and 65% having received the second dose, 73% of the 16-17 year olds having received their first dose and 13% their second dose, and 43% of 12-15 year olds having received their first dose and 0% having received their second dose of the vaccine.

The proportion of people surveyed who said they have been vaccinated for Covid-19 is high. 93% of all respondents have already received at least their first vaccine dose. Of those not vaccinated (and small base must be noted), 6% report they are likely to be vaccinated when a vaccine becomes available to them[34].

How the virus is changing

The variant of concern Delta, also referred to as VOC-21APR-02 (first identified in India) is more transmissible than Alpha variant [35] [36] [37]. It quickly replaced Alpha (VOC-20DEC-01), first identified in the UK, as the dominant strain in Scotland, and 91,372 cases have now been identified as Delta to 13 October 2021.

To date there are five ‘variants of concern’ (VOCs) and eleven ‘variants under investigation’ (VUIs)[38]. There is a concern that some of these new variants may partially escape immunity, from both natural infection and from vaccines currently being deployed and we are monitoring the evidence on this[39] [40] [41]. Up to 13 October there have been 62 genomically confirmed cases of the variant Beta/VOC-20DEC-02 (first detected in South Africa), and 23 cases of Gamma in Scotland. Genomically confirmed cases of other VOCs and VUIs remain low, there have been no new cases of other VOCs or VUIs in the last week (Figure 10). There remains uncertainty regarding the impact of the Delta variant on severity of illness, treatment or reinfections. As more data is analysed we shall become more certain of the impact of Delta on infections, hospitalisations and disease severity and long term vaccine protection effects.

Figure 10: Variants detected in Scotland by sequencing (data up to 13 October and reported weekly) [42]
This line graph shows the number of cases of the variants of concern and variants of interest that have been detected by sequencing in Scotland each week, from 25 January to 13 October 2021.
Beta, also known as VOC-20DEC-02, first detected in South Africa, was increasing steadily since late January from 3 cases to 60 cases on the 7 July, and then increased to 62 cases by 11 August. Beta has remained at 62 cases since then. Eta, or VUI-21FEB-03, first identified in Nigeria, rapidly increased since mid-March and reached 40 cases at the end of May. Eta has remained stable over the last 20 weeks. Gamma increased to 23 cases in the week to 25 August but has not yet increased further. There are also 27 cases of Kappa, or VUI-21APR-01, first identified in India, no change since mid-May. The first case of VUI-21Jul-01 emerged in the week to 4 August with three new case identified in the week to 1 September, however no change over the last 6 weeks. Delta, also known as VOC-21APR-02, first identified in India, has seen a rapid increase in the past 21 weeks to 91,372 cases, an increase of 6,403 cases since the week before.

The effectiveness of vaccines

A large study from the University of Oxford and Office of National Statistics shows that with Delta, Pfizer-BioNTech and Oxford-AstraZeneca vaccines still offer good protection against new infections, but effectiveness is reduced compared with Alpha[43]. Public Health England analysis shows that vaccines are highly effective against hospitalisation from Delta variant with similar vaccine effectiveness against hospitalisation seen with the Alpha and Delta variants at 93% and 96% respectively after two doses of vaccine. There was a 14% absolute reduction in vaccine effectiveness against symptomatic disease after a single vaccine dose with Delta compared to Alpha, and a smaller 10% reduction in effectiveness after 2 doses. Vaccine effectiveness against symptomatic disease is high for both Alpha (89%) and Delta after two doses (79%)[44]. EAVE II data from Scotland also shows that both the Oxford–AstraZeneca and Pfizer–BioNTech Covid-19 vaccines are effective in reducing the risk of SARS-CoV-2 infection and Covid-19 hospitalisation in people with the Delta variant, but effectiveness against infection appeared to be diminished when compared to those with Alpha[45]. The vaccine effectiveness expert committee recently published their consensus view on the effectiveness of different vaccines on infections, symptomatic disease, and severe disease[46]. The protective effects of vaccines wanes over time, and recently the Joint Committee on Vaccination and Immunisation (JCVI) gave advice on a booster programme to re-vaccinate adults against Covid in the UK[47].

Next steps

The Scottish Government continues to work closely with Public Health Scotland and modelling groups to monitor what happens following the high number of cases in Scotland this week and how this effects the course of the epidemic.

Each week this report will provide an overview of the current Covid-19 situation in Scotland. This will include real time data on case rates, hospitalisations and deaths and how Scotland’s figures compare to those from the rest of the UK.

Modelling can tell us where the epidemic is likely to be heading. Local data and data by age group can highlight where problems arise, which can help in addressing some of these issues. In the coming weeks the roll out of the vaccine will continue to be monitored along with the impact of this on case rates and deaths among different age cohorts. Investigations are ongoing by NERVTAG, SPI-M, SAGE, UKHSA, Public Health England and Public Health Scotland regarding the impact of new variants and of vaccination; this will be reflected here as work is undertaken.


Contact

Email: modellingcoronavirus@gov.scot