Coronavirus (COVID-19) state of the epidemic 10 June 2022

Resilience: Vaccine Uptake, Antibody Estimates, and Vaccine Effectiveness

Vaccine Uptake

Vaccinations started in Scotland on 8 December 2020 and there has been a very high uptake. Covid-19 vaccines protect most people against severe outcomes of a Covid-19 infection, but some people will still get sick because no vaccine is 100% effective. The current evidence suggests that you may test positive for Covid-19 or be reinfected even if you are vaccinated, especially since the emergence of the Omicron variant in the UK. The major benefit of vaccination against Omicron is to protect from severe disease. More information is available on the PHS website.

By 6 June, over 4.4 million people had received their first dose, an estimated 90.3% of the population in Scotland aged 12 and older. Over 4.1 million people had received their second dose, an estimated 86.0% of the population aged 12 and older. Additionally, over 3.5 million people in Scotland had received a third vaccine dose, which is an estimated 73.3% of the population aged 12 and older^[48].

The JCVI now advise a spring booster dose of the Covid-19 vaccine for: adults aged 75 years and over (or who will turn 75 by 30 June 2022), residents in care homes for older adults, and individuals aged 12 years and over who have a weakened immune system^[49]. By 6 June, 518,494 fourth dose vaccinations had been administered, with 80.8% of all care home residents having received their fourth dose. It is also estimated that 88.8% of those aged 75 or older have received their fourth dose^[50]. In addition, 21,017 fifth doses have been administered.

Covid-19 Antibody Estimates

The analysis of antibody prevalence can be used to identify individuals who have had Covid-19 in the past or who have developed antibodies as a result of vaccination. As detailed by the ONS, there is a clear pattern between vaccination and testing positive for Covid-19 antibodies but the detection of antibodies alone is not a precise measure of the immunity protection given by vaccination.

According to the ONS Covid-19 Infection Survey, the estimated percentage of adults (aged 16 years and above) living in private households in Scotland who had antibodies against COVID-19 at the 179 ng/mL threshold remained high, at 99.4% (95% credible interval: 99.1% to 99.6%), in the week beginning 9 May 2022. This suggests that they had the infection in the past or have been vaccinated^[51]. This compares to:

• 99.4% in England (95% credible interval: 99.1% to 99.5%),
• 99.3% in Wales (95% credible interval: 99.0% to 99.5%),
• 99.3% in Northern Ireland (95% credible interval: 98.5% to 99.6%)^[52].

The estimated percentage of adults (aged 16 years and above) living in private households in Scotland who had antibodies against COVID-19 at the 179 ng/mL threshold continued to remain high across all age groups, in the week beginning 9 May 2022.

This release of antibody data introduces the reporting of antibody estimates for children (aged 8 to 15 years) for Great Britain (England, Wales and Scotland) as a whole. In the week beginning 9 May 2022, the percentage of children in Great Britain estimated to have antibodies against SARS-CoV-2 at or above the level of 179 ng/ml was high, at 95.5% for children aged 12 to 15 years (95% credible interval: 91.4% to 97.8%), and 94.6% for children aged 8 to 11 years (95% credible interval: 89.7% to 97.2%).

Vaccine Effectiveness Against Omicron

The UKHSA reported that vaccine effectiveness against symptomatic disease, hospitalisation, or mortality with the Omicron variant is lower compared to the Delta variant and that it wanes rapidly. High vaccine effectiveness against all outcomes is restored after the booster dose, with effectiveness against symptomatic disease ranging initially from around 60% to 75% and dropping to around 25% to 40% after 15 weeks; however, from 20 or more weeks after the booster dose vaccine, effectiveness against symptomatic disease has almost no effect. Vaccine effectiveness against hospitalisation ranged from 85% to 95% up to six months after the booster dose with little variation between the type of vaccine used for priming or boost. High levels of protection against mortality were also restored after the booster dose, with a vaccine effectiveness of 94% two or more weeks following vaccination, and dropping to around 88% from 10 weeks after the vaccination for those aged 50 and older^[53].

More data on vaccine effectiveness against the Omicron variant can be found in the UKHSA vaccine surveillance reports. There is a reduced overall risk of hospitalisation for Omicron compared to Delta^{[54] [55]}, with an estimate of the risk of presentation to emergency care or hospital admission with Omicron approximately half of that for Delta^[56]. A non-peer reviewed UK study revealed that risk of Covid-19 related death was 67% lower for Omicron when compared with Delta^[57].