Coronavirus (COVID-19) vaccine certification: evidence paper update

This paper summarises the range of evidence available on vaccination certification schemes. Evidence is drawn from clinical and scientific literature, from public opinion and from international experience.


3. The current state of the epidemic.

3.1 Cases, hospitalisations and deaths

In late August 2021, COVID-19 cases reached a higher peak than the last wave of cases in July 2021. Cases then declined and remained relatively stable throughout October but have started increasing in early November, and remain high across most local authorities[1]. Case rates are lower in fully vaccinated individuals, than unvaccinated and partially vaccinated individuals (Figure 1).

Cases remained broadly stable at around 2,500 new cases a day on average throughout October, but we have seen a gradual increase in cases over the past two weeks (ending 14 November) which are now at around 3,000 new cases a day. In the latest week (ending 14 November) cases increased across all age groups under 60, but fell for those 60+.

Figure 1: COVID-19 rate per 100,000 individuals eligible for vaccination by vaccination status, 7-day rolling average from 10 May 2021 to 12 November 2021.
The chart shows that the COVID-19 case numbers for unvaccinated, 1 Dose and 2 Dose individuals were at a very low level of under 10 per 100,000 on the 10 May. All showed an increase with a peak in early July, before dipping back down at the beginning of August and then increasing to a greater level than before in late August/early September. Unvaccinated and 1 dose cases per 100,000 are higher than 2 dose cases per 100,000  throughout. Unvaccinated peak at around 90 positive PCR tests per 100,000 in July and 180 per 100,000 in early September. 2 dose peak at around 25 per 100,000 in July and 70 per 100,000 in September. 1 dose peak at around 65 per 100,000 in July and 180 per 100,000 in September. During September cases decrease in all group to roughly 40 per 100,000 for all groups at the end of October. Unvaccinated and 1 dose have risen slightly since then while 2 doses has remained relatively flat.

Note: Vaccination status is determined as at the date of PCR specimen date. The data displayed within the greyed-out section (3 days) are considered preliminary and are subject to change as more data is updated.

Source: Public Health Scotland - Scotland COVID-19 Statistical Report

COVID-19 related acute hospital admissions fluctuated over the past month but started to decrease[2]. Hospitalisation rates are higher among unvaccinated individuals (Figure 2).

Figure 2: Age-standardised hospitalisation rate of acute hospital admissions where an individual had a COVID-19 positive PCR test up to 14 days prior, on admission, or during their stay in hospital, per 100,000 individuals eligible for COVID-19 vaccination by vaccination status, seven-day rolling average from 10 May 2021 to 12 November 2021
The chart shows that the age standardised hospitalisation rate for unvaccinated, 1 Dose and 2 Dose individuals was at almost 0 per 100,000 individuals eligible for COVID-19 vaccination on 10 May 2021. All groups then increased. Unvaccinated and 2 dose peaked in July 2021 before dipping down in August whereas 1 dose remained steady. All groups increased to a greater level than before in September before decreasing again. The unvaccinated group has been slightly increasing since October. Unvaccinated peaked at just over 2.5 per 100,000 in July and just over 5 per 100,000 in September. The 1 dose group does not give a smooth line due to the limited data available, however the group remained at around 1 per 100,000 throughout July and peaked at around 5 per 100,000 in September. The two dose group peaked at around 1.5 in July and stayed below 2.5 per 100,000 throughout the time period.

Note: Vaccination status is determined as at the date of positive PCR test. The data displayed within the greyed-out section (1 week) are considered preliminary and are subject to change as more data is updated. 95% confidence intervals are shown as the shaded regions. Age-standardised hospitalisation rates are per 100,000 people per week, standardised to the 2013 European Standard Population.

Source: Public Health Scotland COVID-19 Statistical Report 22 September 2021

Of those individuals that have been fully vaccinated, from 29 December 2020 to 5 November 2021, 0.034% have died with COVID-19 recorded as an underlying or contributory cause of death[3].More information on the current situation as of 12th November in Scotland can be found in the Coronavirus (COVID-19) state of the epidemic 12 November 2021 - gov.scot (www.gov.scot) which is updated and published on a weekly basis[4].

3.2 Forecasts for the medium term

Predictions of the impact of Covid-19 on the NHS in terms of estimated number of infections, hospitalisations and ICU over the coming weeks are modelled by Scottish Government analysts (Figures 3, 4 & 5) and show three projections over the four weeks to 13th December.

'Central' assumes that infections will rise or plateau at the current level, resulting from a small rise in transmission. 'Worse' assumes a larger rise in transmission from the current level. 'Better' assumes a small drop in transmission[5].

Figure 3: Medium term projections of modelled total new daily infections, adjusting positive tests [6] to account for asymptomatic and undetected infections, from Scottish Government modelling, based on positive test data reported up to 15 th November.
Modelled projections of daily infections show the actual data remaining fairly stable since the beginning of November at around 6000 daily infections. The ‘central’ projections through to mid-December remain level but have a large range from 3,000 up to over 10,000 indicating the high uncertainty. The ‘better case scenario’ projection decreases slightly throughout the same time period with a range of 1000-4,000.

Source : Coronavirus (COVID-19): modelling the epidemic (issue no. 78) - gov.scot (www.gov.scot)

Figure 4 shows the impact of the projections on the number of people in hospital. The modelling includes all hospital stays, whereas the actuals only include stays up to 28 days duration that are linked to Covid-19. Hospital and ICU occupancies have plateaued. There continues to be uncertainty over hospital occupancy and intensive care in the next four weeks.

Figure 4: Medium term projections of modelled hospital bed demand, from Scottish Government modelling, based on positive test data reported up to 15th November.
Modelled projections of hospital bed demand show the actual data during the beginning of November where it reaches around 750 beds and levels off. Central projections have a wide range during the end of November  which continues into December reaching between around 400-1,200 by mid-December. Projections in a better scenario suggest that bed demand could decrease to around 500 beds.

Source: Coronavirus (COVID-19): modelling the epidemic (issue no. 78) - gov.scot (www.gov.scot)

Figure 5: Medium term projections of modelled ICU bed demand, from Scottish Government modelling [7], based on positive test data reported up to 15th November.
Modelled projections of ICU bed demand show central projections having a wide range during the end of November which continues into December reaching between around 40-130 by mid-December. Projections for ‘better’ scenarios drop to around 50 beds.

Source: Coronavirus (COVID-19): modelling the epidemic (issue no. 78) - gov.scot (www.gov.scot)

More information on the Scottish Government modelling can be found in the Coronavirus (COVID-19): modelling the epidemic in Scotland report which is updated and published on a weekly basis[8].

What the above predictions tell us is that there is still a degree of uncertainty about the future.

3.3 Vaccination progress

Vaccine uptake has progressed extremely well in the Scottish adult population with approximately 79% of 18 to 29 year olds and 77% of 16 to 17 year olds having received the first dose of the vaccine. Around 96% of people aged 40 and over have received two doses [9] [10], see Figure 6. This puts Scotland in a different position to a number of other countries where vaccination rates were much lower when certification was introduced.

Figure 6: Total Dose 1 (first chart) and Dose 2 (second chart) % coverage by age group in Scotland
The chart shows the different vaccine levels separated by age for dose 1 and 2. For dose 1: 12 to 15 = 56.8%; 16 to 17 = 76.6%; 18 to 29 = 78.6%; 30 to 39 = 84.6%; 40 to 49 = 92.1%; 50 to 54 = 96.7%; 55 to 59 = 99.3%; 60 to 64 = 100%; 65-69 = 100%; 70 to 74 = 100%; 75 to 79 = 100%; 80+ = 100%. For dose 2: 12 to 15 = 1.2%; 16 to 17 = 18.8%; 18 to 29 = 68.9%; 30 to 39 = 77.5%; 40 to 49 = 87.7%; 50 to 54 = 94.1%; 55 to 59 = 97.3%; 60 to 64 = 100%; 65-69 = 100%; 70 to 74 = 99.5%; 75 to 79 = 100%; 80+ = 100%.
Figure 7: Cumulative total number of vaccinations by dose in Scotland
The chart shows the cumulative vaccine uptake for dose 1, dose 2 and booster or Dose 3. Dose 1 increasing rapidly from January 2021 to July 2021 then increasing at a slower rate since. Dose 2 increases rapidly between April 2021 and August 2021 before levelling off. The booster or dose 3 has been increasing rapidly since the end of September. Dose 1 is currently at just over 4.3 million vaccines, dose 2 around 3.9 million and booster or dose 3 at just over 1.3 million.

Source: COVID-19 Daily Dashboard | Tableau Public. Updated 17 November 2021, data related to 16 November

Projections of vaccination activity over the coming weeks in combination with estimated cohort sizes suggests a first dose coverage of the 16-40 year old population of around 81.5% and a second dose coverage of around 69.2% by early December. For over 40 year olds first and second dose coverage is projected to be around 98.4% and 97.1% respectively by early December.

3.4 The impact on the Health service

The COVID-19 pandemic is having an impact on health and social care in Scotland in a number of ways. Demand continues to be very significant, with general demand mirroring levels experienced during pre-Covid-19 winter months. However, it is important to note that the NHS and social care system is responding to these pressures within an environment constrained by Covid-19 and with sustained level of Covid-19 cases and occupancies. Pressures are driven in part by society returning to more normality and patients feeling more comfortable to use health and care services again as well as a significant level of acute and ICU capacity re-directed to caring for Covid-19 cases.

Urgent care, in terms of A&E and acute beds, has been the subject of significant pressures over many months. This is likely to be driven, at least in part, by Covid-19 cases and delayed discharges but also may reflect that patients with higher acuity are now attending A&E, requiring admission. In December 2020, when there were around 1,000 COVID patients in hospital, there were around 19,000 A&E attendances per week; now A&E attendances are around 24,000 per week. From the summer of 2021, performance against the A&E four hour standard has dropped below 80% and has remained at this rate for a prolonged period of time. During week ending 31 October 2021, 71.4% of attendances at A&E services were seen and resulted in a subsequent admission, transfer or discharge within 4 hours[11].

Hospitals are currently at, or very close to, capacity and have been in this position for many weeks now with several Health Boards operating within an environment of unprecedented pressure and heightened risk plus a requirement for military support. This affects how people are using those services, and how this impacts on health, demonstrated by the fact that there is a growing backlog in care developing. Since the onset of the pandemic (April 20-June 21), 46.8% fewer elective inpatient and day case patients have been seen compared to pre-pandemic (April 18-June 19); this represents approximately 164,000 patients in total. For the quarter ending June 2021, inpatient and day case activity was at 72.8% of pre-Covid levels (June 2019) and in the quarter ending June 2020 activity was at 20.7% of pre-Covid levels (June 2019)[12]. Statistics for the period up to the of end September 2021 will be published on 30 November 2021.

As we prepare for winter, our primary and secondary health and social care services are facing arguably the most significant and increasing pressures and demands in the history of the NHS. Whilst the number of people in hospital with recently confirmed COVID-19 has decreased from the recent high in mid-September, it remains stubbornly high and the future trend is uncertain. The rapid rise in Covid-19 cases and hospitalisations in Scotland between late August and early September justified the need to take action to reduce transmission in high risk settings in order to reduce the risk of serious illness and death and alleviate pressures on the NHS.

There is uncertainty as to how much Covid-19 infections will increase or decrease in coming weeks. As we move into the traditionally challenging winter months, Hospital and ICU Covid-19 occupancies appear to be plateauing but the scale of any future change in hospital occupancy and intensive care use is highly uncertain, and depends on the number of infections[13] and the success of the booster programme.

Contact

Email: modellingcoronavirus@gov.scot

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