Learning from 25 years of preventative interventions in Scotland

5. Covid-19 Vaccines

The Covid-19 vaccination programme: preventing severe disease

The Covid-19 vaccination programme was the largest immunisation effort in Scotland’s history. The first vaccine was administered in December 2020 and by August 2022, four in five adults had received at least three doses. This mass vaccination programme saved tens of thousands of lives and prevented many more admissions to hospital.

Introduction

The Covid-19 vaccination programme is an example of a primary preventative intervention. The Covid-19 pandemic presented an unprecedented public health challenge. At its start, there were no evidence-based therapeutic interventions or vaccines to prevent or treat Covid-19. The development of these substantially altered the course of the pandemic. Delivering them to the population of Scotland was the result of rapid and collaborative work, with effectiveness demonstrated by one of the first national scale healthcare surveillance platforms in the world.

Context

Cases of a novel coronavirus (SARS-CoV-2) were first detected in China in December 2019, followed by a rapid spread to other countries. This led the World Health Organisation (WHO) to declare a Public Health Emergency of International Concern (PHEIC) on January 30^th, 2020, and on the 11^th of March, to characterise the outbreak as a global pandemic.^[109] The first case of Covid-19 in Scotland was confirmed on March 1^st 2020.^[110]

It was apparent early on that effective vaccines would be required as part of the response to the pandemic. Scientists from around the world worked collaboratively to develop these, assisted by existing knowledge and approaches along with rapid funding. Rollout of these in Scotland was achieved by a complex programme involving four nations’ collaboration and multi-agency working at national and local level.

Response

Immunisation policy in Scotland is determined by Scottish Ministers and guided by advice from the Joint Committee on Vaccination and Immunisation (JCVI). Four nations’ engagement and decision-making led to the creation of the UK Vaccines Taskforce, which procured Covid-19 vaccines on behalf of all four UK administrations, to achieve economies of scale. There was associated close joint working on vaccine supply, demand and logistics.

By July 2020, several vaccine candidates had found positive results in clinical trials. The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) gave approval to the Pfizer-BioNTech vaccine on 2^nd December 2020^[111], accompanied by interim advice from the JCVI. This was closely followed by regulatory approval for the Oxford-AstraZeneca vaccine^[112], followed by several others. In anticipation of imminent approval of the first vaccines, the then Cabinet Secretary for Health and Social Care set out in a parliamentary statement on 19^th November the initial plans for roll out.

Intervention

The vaccination programme began in Scotland on 8 December 2020. The roll out followed JCVI advice on prioritisation, beginning with the most vulnerable - older adults including in care homes. Over time this extended to all adults over the age of 18; young people aged 12 to 17 who had underlying health conditions that put them at higher risk of severe illness; and children and young people aged 12 and over who were household contacts of people who were immunosuppressed. The programme was later further extended in line with JCVI advice to take in children aged from 5 to 11, and to offer booster vaccinations.

The Scottish Government published its Vaccine Deployment Plan on 14 January 2021, with updates published on 26 March 2021 and 23 July 2021.^[113] An autumn/winter vaccination strategy was published on 30 September 2021 and updated on 21 December 2021.^[114] NHS Scotland worked to ensure the greatest possible uptake and that the vaccination programme was accessible and equitable. This involved an integrated programme of public health communications, flexible delivery models, accessible transport and venues for vaccination, and engagement and co-production with specific groups and communities. Co-production was particularly important, as evidence from other vaccine programmes suggested that uptake would be unequal, and that certain groups and communities may not be reached or engage. Uptake was carefully monitored from the outset, with the programme adapting over time to tailor communication and outreach to groups with lower rates of vaccination. A dedicated workstream on vaccine inclusion^[115] was part of the response, involving joint working with local authorities and the voluntary sector as well as the NHS.

The scale of delivery was rapid and substantial. By August 2022, four in five adults living in Scotland had received at least three vaccine doses (79%, around 3.5 million people).^[116]

Monitoring and Evaluation

A wide range of studies were conducted to evaluate different interventions to address the effects of the Covid-19 pandemic. For the vaccine programme, a national research programme was carried out using the EAVE surveillance platform. The original EAVE study was established during the 2009 swine flu pandemic to assess the effectiveness of vaccines. The researchers involved recognised that their work could be useful in future epidemics or pandemics and received permission from the funder (the National Institutes for Health Research – NIHR) to put it into hibernation, which involved modest funding to maintain it until it was needed again.^[117]

When the Covid-19 pandemic began, the team ‘re-awakened’ the platform which became EAVE II (Early Pandemic Evaluation and Enhanced Surveillance of Covid-19), funded by NIHR, the Medical Research Council and Health Data Research UK. It involved a multi-disciplinary team led by the Usher Institute at the University of Edinburgh, along with Public Health Scotland (PHS) and four other Universities in Scotland. It was supported by the Scottish Government and involved everyone registered with a GP in Scotland – around 98% of the population^[118], making it one of the first national scale healthcare surveillance platforms in the world.

EAVE II involved a prospective observational cohort which was used for two main purposes: to contribute to monitoring the progress of the pandemic; and to evaluate the effectiveness of therapeutic interventions and vaccines.^[119] This involved a linked dataset using Scotland’s national patient identifier (the CHI number). Data about patient characteristics and medical conditions, GP consultations, prescriptions, results from Covid-19 tests, hospital admissions, deaths, maternity and birth records and a range of other information was linked to examine different research questions. The data were anonymised and held securely on a server hosted by PHS where only trained and approved analysts could access it.^[120] Findings were made available to decision-makers in real time and before publication, via briefings, submissions and involvement in relevant advisory groups. This rapid access to results informed the pandemic response.

Key Findings

a) Improved outcomes

Prior to the launch of the Covid-19 vaccine programme, the EAVE II team conducted several studies that identified which groups were most at risk, helping to determine who would benefit most from the vaccine roll out.^{[121],[122],[123]} Once the vaccines began to be administered, the researchers were able to examine their effectiveness.

An interim analysis^[124] focused on the first vaccine dose. It involved 1.33 million people who were vaccinated between 8^th December 2020 (the start of the programme) and 22^nd February 2021, focusing on the period 28-35 days after the first dose, by which time it would have taken effect. For both vaccines being delivered at the time (Pfizer-BioNTech and Oxford-AstraZeneca) they found an 89% reduction in the risk of hospitalisation. They also identified that the vaccines were equally effective for people aged 80 and older. These were landmark results, the first to demonstrate vaccine efficacy outside of clinical trials, and the first national study in the world.

A subsequent paper^[125] examined adverse events from the first dose of vaccination, following reports to the MHRA and other regulators relating to some patients who had received the Oxford-AstraZeneca vaccine. These reports resulted in some countries restricting the use of this vaccine, including all of the UK (to certain age groups) following JCVI advice. The EAVE II analysis found small increases in the risk of clotting and bleeding events, but these events were very rare. The risk of them was similar to other common vaccines given for Hepatitis B and influenza, for example. These findings emphasised the benefit of having both doses and resulted in several countries altering their vaccine policy positions.

Other studies from EAVE II provided more information about: trends and forecasting in terms of hospitalisations and deaths from Covid-19 as the pandemic continued^[126]; the effectiveness of vaccines against new variants^{[127],[128],[129]}; waning of vaccine doses (helping to inform the roll out of boosters)^[130]; how obesity accelerates the loss of vaccine immunity^[131]; and the effectiveness of Covid-19 vaccines in pregnancy^[132], among many other analyses.

b) Cost savings

The roll out of Covid-19 vaccines in Scotland was based on advice from the JCVI along with additional national considerations. The JCVI advice did not involve the use of cost-effectiveness assessments given that the alternative to vaccine roll-out was ongoing, highly costly restrictions on social and economic activities via distancing measures.

EAVE II was not designed to examine cost-effectiveness and did not include an economic evaluation. However, there is international evidence in terms of reductions in hospitalisations and mortality following the roll out of Covid-19 vaccines. A recent systematic review of the cost-effectiveness of these vaccine programmes^[133] in multiple countries concluded that these programmes were cost-effective or cost saving regardless of vaccine type. Mass vaccination was identified in the review as particularly cost-effective when there was a system of prioritisation (based on clinical need) in place, adequate supply and when the programme was delivered at pace – all elements that characterised the programme in Scotland.

PHS contributed to a Europe wide analysis^[134] of deaths averted due to the roll out of Covid-19 vaccines in people aged 25 and over in 33 countries between December 2020 and March 2023, updating an earlier analysis^[135] up to November 2021. This found that 22,138 deaths were averted in total, 71% of expected deaths if vaccines had not been available. This was one of the highest in Europe due to the early implementation of the programme, that it covered large parts of the population and had high vaccine coverage. Although the study did not quantify cost savings due to averted deaths, these would be substantial.

c) Addressing inequalities

Significant effort was made during the pandemic to ensure that all eligible groups had access to vaccination. This work included the vaccine inclusion workstream mentioned above⁷, as well as reports and recommendations from the PHS Vaccine Confidence and Equity team.^[136] Despite these efforts, EAVE II and other studies identified inequalities in the uptake of Covid-19 vaccines in Scotland, which had been noted in previous vaccine programmes and UK and international evidence during the pandemic. In an analysis published in September 2022⁸, EAVE II researchers and collaborators identified the factors most likely to predict inequalities in vaccine uptake among adults. Excluding those with expected reasons for not receiving a vaccine (including contraindications) they found that men, people living in the 20% least affluent areas, those living in large urban areas, people with no underlying health conditions and people under aged 50 were most likely to be unvaccinated. However, a significant number had three or more underlying conditions. This analysis did not include ethnicity, which studies elsewhere in the UK^[137] identified was a significant factor in inequalities in vaccination. Other analysis found the risk of Covid-19 hospitalisation or death was higher in certain ethnic minority groups in Scotland.^[138] The vaccine programme (for both flu and Covid-19) in Scotland began routinely collecting ethnicity data from November 2021 and continues to do so.

Learning and Next Steps

The development and delivery of vaccines transformed the trajectory of the pandemic and saved countless lives. The quality and extent of the research conducted alongside the vaccine programme provides invaluable lessons for the future. This learning also serves as the foundation for a longer-term programme of work. Covid-19 vaccines continue to be delivered by NHS Scotland to those most at risk of severe disease.

EAVE II has received international recognition. This includes, among other awards: the Royal Statistical Society’s Florence Nightingale award for excellence in healthcare data analytics; the Royal Society of Edinburgh Mary Sommerville Medal for exceptional teamwork and collaborations; and both the Liley Medal from New Zealand’s Royal Society Te Apārangi and Health Research Council and HDRUK’s impact of the year award (2021) for work investigating the real-world effectiveness of the early COVID-19 vaccines.^[139] The EAVE II platform has now been adapted so that it can continue to serve as a valuable source of data for the ongoing surveillance and assessment of respiratory infections in Scotland.