Key scientific concepts

¶1.16. Initial information about new viruses is always limited. Covid-19 was initially identified as pneumonia, but within a few days the World Health Organization announced that the cause of an outbreak in Wuhan in the Hubei province of China had been identified as a novel or new coronavirus.¹⁰¹⁰ INQ000236523_0001 As summarised in the Inquiry's Module 1 Report, coronaviruses are a large family of respiratory viruses.¹¹¹¹ Module 1: The resilience and preparedness of the United Kingdom, UK Covid-19 Inquiry, July 2024, Chapter 1 (https://covid19.public-inquiry.uk/documents/module-1-full-report) They cause a diverse range of illnesses, from the common cold to life-threatening conditions such as severe acute respiratory syndrome (SARS) and the highly deadly Middle East respiratory syndrome (MERS). Some coronaviruses transmit easily from person to person, while others do not.¹²¹² INQ000236523_0001

¶1.17. In order to assess the threat posed by any new and rapidly growing epidemic, it is vital to understand as quickly as possible some key aspects of how the virus is transmitted between people and how severe the illness it causes can be.¹³¹³ This was recognised in the UK Influenza Pandemic Preparedness Strategy 2011, Department of Health, 10 November 2011 (https://assets.publishing.service.gov.uk/media/5a7c4767e5274a2041cf2ee3/dh_131040.pdf; INQ000022708)

Understanding transmissibility

¶1.18. In order to assess the risk posed by an emerging virus, it is essential to know how contagious it is (ie whether and how easily it is transmitted between people).

¶1.19. Evidence of person-to-person transmission is "the critical tell-tale sign of a potential pandemic".¹⁴¹⁴ INQ000232194_0024 para 95 Some viruses are only capable of transmitting between a small number of people who are in close contact with each other – such as in a family, care or work setting – before dying out. This is referred to as 'limited' person-to-person transmission. Other viruses may be able to continue spreading with ease from one person to the next within the wider community. This is known as 'established' or 'self‑sustaining' person-to-person transmission. At SAGE's first meeting to discuss the outbreak on 22 January 2020, it was not known whether sustained transmission was occurring.¹⁵¹⁵ INQ000061509_0003 para 7

The speed of transmission

¶1.20. Transmissibility is affected by:

the extent to which an infection is transmitted without symptoms;
the route of transmission;
the incubation period (ie the period of time between infection with a disease and the appearance of symptoms, which is often linked to when a person becomes infectious to others);¹⁶¹⁶ INQ000270553_0008 para 4.3 and
the generation time (ie the period between a person becoming infected and when they infect another person).¹⁷¹⁷ INQ000270553_0009 para 4.6

¶1.21. The transmissibility of a virus is measured by the reproduction number (ie the average number of people that one person with a particular disease infects). The reproduction number is also known variously as the 'R number', the 'R value', 'R0' (R zero), 'Rt' or just 'R'.

¶1.22. References to the reproduction number in the evidence considered by the Inquiry – and references to it in this Report – are generally references to Rt. This is the average number of people that a single infected person passes the virus on to at a particular time point, taking into account current levels of immunity and the extent of social mixing.¹⁸¹⁸ INQ000252450_0013 para 2.15 Whenever Rt is above 1, an epidemic is still growing. Whenever it is below 1, the epidemic is shrinking.¹⁹¹⁹ INQ000251645_0057 para 5.41 It is Rt that interventions such as social distancing were intended to reduce.

¶1.23. Less commonly, there are references to 'R0', which represents the average number of people that one infected person would pass the virus to in a population with normal mixing behaviour and no prior immunity.²⁰²⁰ INQ000252450_0013 para 2.14 R0 can be used to estimate the proportion of a population that will eventually become infected. On 28 January 2020, R0 for Covid-19 was estimated by SAGE to be between 2 and 3 during the first outbreak in Wuhan.²¹²¹ INQ000061510_0003 para 11 If replicated in the UK, this would have translated to about 80% of the population becoming infected.²²²² INQ000119430_0001 para 5

¶1.24. Rt and R0 can be used together to inform estimates of the 'doubling time' (ie how long it will take for the total number of cases to double). A doubling time of one week means that the number of cases will be twice the current size after one week, four times that size after two weeks and eight times that size after three weeks. Estimates of the doubling time of Covid-19 in the UK remained highly uncertain, given the lack of testing and concerns about the extent to which cases were not being identified.

¶1.25. The transmissibility of a virus is also informed by identifying when people become infectious and the period for which they remain infectious:

At its meeting on 22 January 2020, SAGE identified the incubation period for Covid-19 as "within 5 to 10 days" and, by 3 March 2020, had refined this to an average of 5 days, within a range of 1 to 11 days.²³²³ INQ000174700_0002 para 8; INQ000074987_0001 This estimate remained broadly accurate, although the average incubation period of the later Delta and Omicron variants was thought to be shorter.²⁴²⁴ INQ000251645_0055 para 5.31
The 'duration of infectivity' measures the length of time an infected individual remains able to transmit a virus.²⁵²⁵ INQ000251645_0055 para 5.33 By 4 February 2020, SAGE estimated it to be "around 2 weeks" for Covid-19, with an average of 7 days. By 26 February 2020, SAGE refined this to 14 days as an upper limit, with peak infectivity "probably around the start of symptom onset, average 2-6 days, then falling off rapidly".²⁶²⁶ INQ000074896_0001; INQ000051925_0002 para 17

¶Taken together, the incubation period and duration of infectivity are important for informing the design of the response – particularly the length of self-isolation for infected individuals and their contacts.²⁷²⁷ INQ000251645_0056 para 5.39 The upper estimates of an incubation period for Covid-19 of about 11 days, and a duration of infectivity of 14 days, informed the initial recommendation of a 14-day isolation period for contacts of people testing positive.²⁸²⁸ INQ000251645_0055 para 5.32

¶1.26. Increased testing of suspected cases is vital to understanding the true extent of transmissibility, and this was echoed in a message from the World Health

¶Organization on 16 March 2020 imploring all countries to "test, test, test".²⁹²⁹ INQ000512530 The data used to estimate growth also need to cover a sufficiently long period – ideally at least two weeks – to account for factors such as the typical delay in obtaining test results at weekends.³⁰³⁰ INQ000249526_0083-0084 para 258

Routes of transmission

¶1.27. Alongside understanding how quickly a disease is spreading, it is important to understand how the disease spreads from person to person. The five main routes of transmission capable of sustaining a pandemic or major epidemic are: respiratory (eg influenza); sexual and blood-borne (eg human immunodeficiency virus); oral – from water or food (eg cholera); vector transmission from insects or arachnids (eg malaria); and touch (eg Ebola virus disease).³¹³¹ INQ000248853_0088 para 6.2 Respiratory viruses can also transmit via objects or surfaces (known as fomites) that are contaminated by droplets or aerosols exhaled by someone infected, then transferred to people whose hands touch the contaminated surface and then their eyes, nose or mouth.³²³² INQ000236261_0056 para 10.27

¶1.28. Covid-19 was understood from an early stage to transmit predominantly via respiratory routes.³³³³ INQ000248853_0099 para 6.51 However, there was considerable uncertainty about the extent of transmission at closer range (typically one to two metres) via larger respiratory droplets and through very small airborne aerosols that can remain in the air for long periods of time and infect at greater distances. In the early stages of the pandemic, scientists thought most transmission was likely to be via droplets, with some fomite transmission and less aerosol spread.³⁴³⁴ INQ000238826_0112 para 339 Initial advice from the World Health Organization in December 2019 suggested that the virus spread "mainly" through droplets or shorter-range aerosols, but by July 2020 there was a growing body of evidence supporting the importance of airborne transmission.³⁵³⁵ INQ000236522_0004; see also INQ000203978_0001; INQ000236261_0049-0050 para 10.9 Over the course of the pandemic, there was only a small amount of epidemiological evidence showing that a significant amount of Covid-19 was transmitted by fomites, and advice given by scientists shifted from a strong focus on cleaning surfaces and washing hands to a greater emphasis on ventilation.³⁶³⁶ INQ000236261_0057 paras 10.33-10.34

¶1.29. It is also important to understand the extent to which an individual who does not display symptoms (someone with an 'asymptomatic infection') can infect others. This is known as 'asymptomatic transmission'.³⁷³⁷ There is also 'presymptomatic transmission', where the infection is passed on by someone who was not displaying symptoms at the time but who goes on to develop symptoms of illness later. In the absence of mass diagnostic testing, it is not possible to calculate the spread of a virus if symptoms are not detectable. If infected people do not show symptoms, it means that they will not know to self-isolate before they infect others. As explained by Professor Sir Michael McBride (Chief Medical Officer for Northern Ireland from September 2006):

" [T]here is a very different response required for planning for and responding to a pandemic which has asymptomatic transmission."³⁸³⁸ Michael McBride 10 May 2024 68/19-21

¶1.30. With a reliable test, it is possible to measure the proportion of asymptomatic infections by testing a sample of the population. In February 2020, modellers from Imperial College London used data from repatriation flights from China to estimate that one-third of infections of Covid-19 were asymptomatic.³⁹³⁹ Neil Ferguson 17 October 2023 134/7-20; see also the SAGE meeting on 10 September 2020, which noted that a review of 22 studies put the figure at 28%, albeit with very wide confidence intervals (INQ000061564_0005 para 31)

¶1.31. However, measuring the proportion of onward asymptomatic transmission is more complex, as people without symptoms will not generally be tested and the chain of transmission is unlikely to be identified unless they are tested by chance.⁴⁰⁴⁰ INQ000251645_0053-0054 para 5.25 At its meeting on 28 January 2020, SAGE noted that there was "limited evidence of asymptomatic transmission" but that early indications implied "some is occurring".⁴¹⁴¹ INQ000061510_0003 para 16 A Public Health England study carried out in six care homes across London during April 2020 identified that almost 40% of residents had tested positive for Covid-19, of whom nearly 45% were asymptomatic.⁴²⁴² INQ000089681_0003 It concluded that "symptom-based screening alone is not sufficient for outbreak control".⁴³⁴³ INQ000089681_0004 Mr Hancock told the Inquiry that this study formed the basis for adopting an assumption that asymptomatic transmission was occurring.⁴⁴⁴⁴ INQ000232194_0083 para 346

¶1.32. Understanding the extent of asymptomatic transmission is critical to the design of the response to a virus.⁴⁵⁴⁵ INQ000252450_0015 para 2.25 The significant proportion of asymptomatic transmission during the Covid-19 pandemic, for example, increased the importance of contact tracing to monitor the spread of the virus and meant that personal protective equipment (PPE) needed to be used in a much wider range of settings.

Understanding severity

¶1.33. It is also critical to understand the severity of a new disease in the early stages of any pandemic to understand how many people might die as a result of infection.⁴⁶⁴⁶ The case fatality ratio and infection fatality ratio only measure the direct severity of the virus itself and do not account for deaths indirectly related to the spread of the virus, such as those that might arise from healthcare systems being unable to treat other health conditions. Estimates of fatality ratios are "fundamental to determining policy strategy".⁴⁷⁴⁷ INQ000249526_0040 para 126; INQ000310090_0003 para 19 Severity can be measured by the case fatality ratio and the infection fatality ratio.

¶1.34. The case fatality ratio is the proportion of those with a recognised case of infection who die from it. At its simplest, the case fatality ratio can be calculated as the total number of recognised deaths divided by the total number of recognised cases. However, this does not take into account unrecognised cases – particularly those where individuals have mild or no symptoms. If the recognition of cases improves (eg through more testing) then the case fatality ratio will often be corrected downwards, which would also reduce the overall expected death toll of the pandemic. At a meeting on 11 February 2020, SAGE reported an uncertain case fatality ratio of 2% to 3%.⁴⁸⁴⁸ INQ000061514_0003 para 9

¶1.35. The infection fatality ratio is the true proportion of all infected individuals, including those without symptoms, who die because of the infection. Estimates of the infection fatality ratio attempt to correct for biases in testing and errors in attribution of the cause of death. The true underlying number can decrease significantly over time due to natural immunity, vaccines and therapeutics, but can increase significantly if pressure on healthcare systems means infected people are not receiving timely or effective treatment. In a February 2020 report, Imperial College London estimated an infection fatality ratio for Covid-19 of approximately 1%.⁴⁹⁴⁹ Report 4: Severity of 2019-Novel Coronavirus (nCoV), Imperial College London, 10 February 2020, p1 (https://www.imperial.ac.uk/ media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-severity-10-02-2020.pdf; INQ000236277) As Professor Neil Ferguson (Mathematical Epidemiologist at Imperial College London) explained:

¶" 80% of the population being infected translates into approximately 500 thousand deaths in the UK."⁵⁰⁵⁰ INQ000249526_0040 para 126

¶However, the infection fatality ratio for Covid-19 varied significantly by age. On 4 March 2020, SAGE endorsed assumptions of a rate for people aged 19 and under of 0.01%, and for those aged 80 and over of 8.76%.⁵¹⁵¹ INQ000074987_0002

Understanding potential responses to a pandemic

¶1.36. In the early stages of the pandemic, one of the main priorities was to establish the likely impact of Covid-19 if it arrived in the UK in order to design a response.

¶1.37. In advance of sufficient data, a reasonable worst-case scenario was used as a tool for planning purposes to illustrate the worst manifestations of the risk that could reasonably be expected.⁵²⁵² See also Module 1: The resilience and preparedness of the United Kingdom, UK Covid-19 Inquiry, July 2024, Chapter 3 (https://covid19.public-inquiry.uk/documents/module-1-full-report) It was not a prediction of what would happen, but the worst that could reasonably happen if no countermeasures were put in place.

¶1.38. It was agreed in January 2020 that the reasonable worst-case scenario for pandemic influenza should be used for government planning for Covid-19 until sufficient data emerged.⁵³⁵³ INQ000061510_0004 para 27 As a result, plans proceeded on the basis of:

¶" the reasonable worst-case scenario … similar to a medium flu pandemic (with the added challenge of no vaccine)".⁵⁴⁵⁴ INQ000233747_0002

¶Although it was not a prediction of what would happen, it was calculated that as many as 820,000 people in the UK might die.⁵⁵⁵⁵ INQ000232194_0038 para 159; INQ000320718_0002 This would, of course, shape the response.

Strategies

¶1.39. There are three key strategies that can be adopted in response to a pandemic (see Table 1), although the distinctions between these approaches continued to evolve during the course of the Covid-19 pandemic.

¶1.40. Under a 'mitigation' strategy, the spread of the virus is seen as inevitable. Any interventions in response are aimed at reducing or slowing the spread of the virus to reduce its peak – rather than reversing its growth – and are therefore relatively minor, such as advising people to minimise contact with others. Rt would be reduced but would remain above 1 and the epidemic would continue to grow. The pandemic would peak at a lower level over a longer period, rather than there being a higher peak of infections over a comparatively shorter period.⁵⁶⁵⁶ INQ000249526_0048 para 150(b) A mitigation strategy reduces the number of people infected with the virus at any one time and therefore also reduces pressure on the healthcare system, while providing some time to research effective treatments or develop vaccines. However, although peak cases would be lower, a similar number of people overall would still eventually be infected. There might be efforts to protect groups likely to be more clinically vulnerable to the virus, rather than applying to the population as a whole – for example, the provision of PPE in hospitals or restrictions on visitors to care homes. The UK Influenza Pandemic Preparedness Strategy 2011 is an example of a mitigation strategy, which had the following as its premise:

¶" It will not be possible to stop the spread of, or to eradicate, the pandemic

influenza virus, either in the country of origin or in the UK, as it will spread too rapidly and too widely."⁵⁷⁵⁷ UK Influenza Pandemic Preparedness Strategy 2011, Department of Health, 10 November 2011, p15 (https://assets.publishing.service.gov.uk/media/5a7c4767e5274a2041cf2ee3/dh_131040.pdf; INQ000022708)

¶1.41. A 'suppression' strategy aims to deploy more stringent or widespread interventions that bring Rt below 1 to reverse the growth of the epidemic. Strict interventions such as physical distancing and legally backed 'stay at home' orders can be used to substantially reduce the transmission of cases and bring Rt below 1. The benefit of a suppression strategy is that, since the number of infections in circulation should decline, fewer people will be infected with the virus while the measures are in place. However, a suppression strategy does not bring the epidemic to an end; it will return to growth once interventions are released. As a result, interventions might need to be reintroduced periodically, unless an effective system is in place to test, trace and isolate any new infections or until medical countermeasures become available that can halt transmission of the virus or significantly reduce its severity.

¶1.42. An 'elimination' strategy aims to deploy strict interventions until there is no transmission of cases in the community. Under this approach, strict interventions are introduced and not released until the virus has stopped circulating in the community. Although an elimination strategy aims to reduce cases to effectively zero, the risk of new cases of the virus being reintroduced – particularly through international travel – means that at least some action may be required until such time as effective medical countermeasures are available. Countries that pursued an elimination strategy – often referred to as a 'zero Covid' strategy – during the pandemic were generally geographically isolated islands, such as New Zealand, that were able to apply strict restrictions at international borders to reduce the risk of importing new cases.

¶Table 1: Summary of potential response strategies

¶Strategy Aims Potential public health interventions Mitigation • Slow the rate of virus • Advisory interventions to minimise

transmission, but with Rt contacts remaining above 1 • Measures focused on the protection of • Protect clinically vulnerable clinically vulnerable people, such as people from infection restrictions in care homes

¶Suppression • Reduce the rate of virus • Measures to reverse growth of cases,

transmission until Rt is potentially including lockdowns below 1 • Testing, contact tracing and self-isolation • Prevent healthcare systems • Shielding for vulnerable groups from being overwhelmed

¶Elimination • Eliminate community • Stringent measures, including

transmission maintaining lockdowns until community • Identify and stop chains of transmission is halted transmission • Tight border restrictions and quarantine of arrivals • Testing at scale, with strict isolation of cases and contacts

Interventions (also known as non-pharmaceutical interventions)

¶1.43. Interventions or measures adopted in response to a pandemic (excluding vaccines, drugs or other medical interventions) may seek to:

Prevent someone acquiring the infection: For a virus that transmits through droplets or aerosols, interventions such as physical distancing and encouraging meeting outdoors can help to reduce the risk of transmission.
Prevent individuals passing on the infection: Interventions such as face coverings and encouraging handwashing can help to reduce the risk that an infected person transmits the virus to someone else.
Identify and isolate infected people: Testing to identify infected people, tracing people who have come into contact with infected people and getting infected people and their contacts to self-isolate are all critical to preventing onward transmission of the virus.
Limit transmission: Restrictions on settings where large numbers of people from different households meet, such as schools or hospitality businesses, can help to reduce how widely an infection spreads.
Reduce risk for vulnerable people: Interventions such as shielding can help reduce the risk of catching the virus for those who are particularly clinically vulnerable.⁵⁸⁵⁸ Technical Report on the Covid-19 Pandemic in the UK, Department of Health and Social Care, 1 December 2022, pp234-235 (https://www.gov.uk/government/publications/technical-report-on-the-covid-19-pandemic-in-the-uk; INQ000101642)

¶1.44. It can be difficult to measure the effectiveness of individual interventions. Many common research methods such as randomised controlled trials (eg shielding only part of the clinically vulnerable population) would not be feasible or ethical to conduct during an emergency. The way an intervention is implemented (eg how it is communicated) can also impact its effectiveness. Behavioural responses can also obscure the effect of an intervention, such as people choosing to avoid settings that they perceive to be high risk even when they are not subject to restrictions.⁵⁹⁵⁹ Technical Report on the Covid-19 Pandemic in the UK, Department of Health and Social Care, 1 December 2022, pp239-240 (https://www.gov.uk/government/publications/technical-report-on-the-covid-19-pandemic-in-the-uk; INQ000101642)

¶1.45. It is also critical to note that interventions can have significant downsides, such as the economic harm caused by forcing businesses to remain closed, the social harm caused by closing schools, or the health harm caused by missed screening and treatment of other health conditions.⁶⁰⁶⁰ Technical Report on the Covid-19 Pandemic in the UK, Department of Health and Social Care, 1 December 2022, p235 (https://www.gov.uk/government/publications/technical-report-on-the-covid-19-pandemic-in-the-uk; INQ000101642) Decision-makers therefore need to balance the potential for an intervention to reduce the direct harm of the virus against the potential for it to increase harms elsewhere.

Anticipating and reacting to variants

¶1.46. Variants of a virus will appear regularly, but not all will change the behaviour of the virus or become significant problems.⁶¹⁶¹ INQ000251645_0155-0156 para 8.93 Early detection and notification of variants is of the utmost importance in any pandemic response. As a new variant is identified, key factors such as its transmissibility, the severity of illness it causes and its potential for 'escaping' the immunity conferred by prior infection or vaccines have to be reassessed.

¶1.47. During the Covid-19 pandemic, three 'variants of concern' became dominant at different stages – Alpha, Delta and Omicron. Each of these was more transmissible than previous strains. Omicron in particular exhibited significantly different characteristics from the original strain of the virus. For example, its generation time of between 1.5 and 3.2 days was far shorter than the 6 to 7 days of previous variants, which made Omicron more difficult to contain with test, trace and isolate procedures.⁶²⁶² INQ000213239_0003-0004 para 9

Immunity

¶1.48. Understanding the nature of immunity following infection or indeed vaccination is critical to understanding how an epidemic might come to an end.

¶1.49. Where a population achieves protection from an infectious disease, either through immunity developed from having previously been infected or through vaccination, this is known as 'population immunity' (or 'herd immunity'). It results in fewer people to infect and the spread of the virus gradually slows to a halt. Population immunity provides protection for the whole of a population, including people who have not themselves caught the disease or received a vaccine. The percentage of the population that needs to be infected or vaccinated to achieve population immunity depends on the transmissibility of the disease, with a higher rate of transmission requiring a higher threshold for population immunity.⁶³⁶³ INQ000248853_0091 para 6.15 For example, the basic reproduction number for measles is estimated to be between 10 and 20 (ie a single child with measles will infect between 10 and 20 others), and therefore the World Health Organization has a target of 95% vaccine coverage to achieve and maintain measles elimination.⁶⁴⁶⁴ See Risk Assessment for Measles Resurgence in the UK, UK Health Security Agency, July 2023 (www.gov.uk/government/publications/measles-risk-assessment-for-resurgence-in-the-uk; INQ000548395)

¶1.50. However, population immunity is not an inevitable endpoint for an epidemic. Many diseases never reach this threshold, or only do so temporarily. Immunity might weaken over time to the point that it no longer prevents people from being reinfected, or variants of the virus may emerge that escape prior immunity.⁶⁵⁶⁵ INQ000252450_0017 para 2.35 Understanding the level of protection offered by vaccination or previous infection is therefore critical to understanding whether population immunity can be achieved.⁶⁶⁶⁶ INQ000252450_0017 para 2.36 Vaccination or prior infection may also reduce the severity of any subsequent infection.⁶⁷⁶⁷ INQ000252450_0017 para 2.34 That knowledge will be inherently uncertain in the early stages of an epidemic, when case numbers are small – and especially uncertain for a novel virus.

Complications or resulting conditions

¶1.51. Viral infections can cause long-term illnesses – known as 'long-term sequelae' – after the initial acute infection. While these may appear rare for most viruses, large numbers of cases can occur at the same time when the virus is at the scale of a pandemic.⁶⁸⁶⁸ INQ000251645_0207; INQ000273807_0169 para 12.1 Not all viruses will cause significant long-term illnesses, and this was not a "major common problem" for viruses such as severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), which causes SARS and is closely related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, which causes Covid-19) and Middle East respiratory syndrome coronavirus (MERS-CoV), which causes MERS.⁶⁹⁶⁹ Peter Horby 18 October 2023 222/20-223/2 As Professor Whitty told the Inquiry:

" Some very severe diseases rarely have post infection syndromes whilst other relatively trivial infections can have quite common and prolonged ones."⁷⁰⁷⁰ INQ000251645_0207 para 12.2

¶1.52. While the potential for long-term illnesses to occur is predictable, the scale and characteristics of those illnesses vary from virus to virus and cannot be predicted.⁷¹⁷¹ INQ000273807_0169 para 12.1 The long-term illnesses arising from Covid-19 are commonly described as Long Covid. Over 200 symptoms of Long Covid have been reported, though it often involves fatigue, breathlessness and 'brain fog', impacting on both mental and physical function and leading to disability and impaired health.⁷²⁷² INQ000280198_0011-0012 para 1.14-1.16 Much remains unknown about the mechanisms causing Long Covid.⁷³⁷³ INQ000280198_0016 para 3.4 The percentage of those who go on to develop it following infection with Covid-19 also remains unknown – the World Health Organization has estimated that between 10% and 20% of infected people will develop Long Covid.⁷⁴⁷⁴ INQ000280198_0019 para 4.1-4.2; see also INQ000271436_0075, 0077-0079 paras 231-232, 238-247