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The Ghost of ‘Herd Immunity’ Still Haunts Boris Johnson’s ‘Roadmap’ Out of Lockdown

While other countries are focused on the vaccine, Nafeez Ahmed reveals how the UK’s Cabinet Office asked SAGE to model ‘herd immunity’ through a ‘resurgence’ of infection in young people

Photo: Islandstock/Alamy Stock Photo

The Ghost of ‘Herd Immunity’ Still Haunts Boris Johnson’s ‘Roadmap’ Out of Lockdown

While other countries are focused on the vaccine, Nafeez Ahmed reveals how the UK’s Cabinet Office asked SAGE to model ‘herd immunity’ through a ‘resurgence’ of infection in young people

The Cabinet Office incorporated ‘herd immunity by natural infection’, alongside vaccination, into all the modelling used to develop Boris Johnson’s ‘roadmap’ out of lockdown earlier this year, Government documents examined by Byline Times reveal.

Continuing COVID-19 transmission until summer 2022 will contribute to more than 35% of overall herd immunity, according to one model commissioned by the Government.

Among the documents from the Scientific Advisory Group on Emergencies (SAGE) – previously unreported until now – one presented to the group in February summarised modelling by the University of Warwick and Imperial College London based on scenarios defined by the Cabinet Office.

The document signed off by chairs of SAGE’s Scientific Pandemic Influenza Group on Modelling sub-group came to the conclusion that insufficient levels of vaccination in the UK would mean that “herd immunity is not reached without a large resurgence of transmission”. The modelling described by the document suggests that the bulk of this “large resurgence of transmission” would be concentrated in young people. The documents reveal that the specific scenarios explored by SAGE modelling were created by the Cabinet Office.

It is important to note that scenarios explored by the roadmap’s modelling do not necessarily represent policy decisions. A Government spokesperson told Byline Times that any suggestion of a policy of deliberate infection is “categorically untrue” and added: “As we’ve made repeatedly clear, herd immunity was never part of our pandemic strategy.”

But this still leaves the question why an “escalation of infection” as a route to population immunity is being modelled at all. Other countries are seeking this outcome through vaccination rather than trying to harness natural infections.

Third Wave Deaths

The modelling described by the SAGE document was designed to figure out how and when a combination of vaccination and natural infection of largely unvaccinated young people would contribute to overall population immunity – or ‘herd immunity’. This in turn would provide a guide as to how early the Government could relax restrictions. 

The research warned that removing restrictions too early could lead to “another wave comparable in size to January 2021, resulting in a further 62,000 to 107,000 deaths in England”. More pessimistic assumptions, such as reduced vaccine effectiveness and uptake, could lead to a still larger wave with between 102,000 and 176,000 deaths, according to the document.

The SAGE document shows that the role of natural infection in producing immunity was a crucial variable in the modelling for the roadmap. “These models assume that neither naturally acquired nor vaccine-induced immunity wane,” it stated. “Immunity to other coronaviruses is known to wane.”

In one scenario outlined by the document, it stated: “A resurgence occurs because there are still many people in vulnerable groups who do not have protection; neither directly (either because they have not been vaccinated, or because their vaccination has not prevented them from becoming infected then ill) nor indirectly from wider population immunity (because many younger age groups have not yet been vaccinated or infected).”

The document point outs out that, as a result, herd immunity might only be achievable with a “large resurgence of transmission” primarily affecting unvaccinated children. Because a “large proportion of adults remain who are not directly protected by vaccination” and as “many younger age groups have not yet been vaccinated or infected”, the document concludes that this could mean that overall UK population level protection is too low to achieve herd immunity by vaccination alone.

“Only around 79% of the population are adults, which means population level protection is lower, at 53%,” it stated. “In addition, protection against infection is likely to be lower than that against disease. As a result, herd immunity is not reached without a large resurgence of transmission.” 

The emphasis in bold was present in the original document, indicating the significance of the connection between the goal of “herd immunity” and “a large resurgence of transmission”.

Herd Immunity Variable Added by Cabinet Office

Other SAGE documents reveal how the scenarios modelled by the Government’s scientific advisors earlier this year were designed by the Cabinet Office to incorporate the role of natural infection in contributing to population immunity. 

The earliest available version of an Imperial College ‘Unlocking roadmap scenarios’ model dated 5 February, commissioned by the UK Government, made no mention at all of immunity acquired by natural infection. 

However, a second version of that model dated 18 February went to pains to incorporate immunity after infection into estimates of overall population protection. Both documents confirm that the scenarios for lifting restrictions were “set out by the Cabinet Office.” The later version estimated that at the time 32% of the population of England was “protected via prior infection- and/or vaccine-induced immunity.” 

The paper went on to suggest that protection via natural infection would play a key role in contributing to overall population immunity all the way through to January next year, projecting a clear rise in the number of people “protected after infection” from late April 2021 starting at around 18%, to approximately 22% of the population by January 2022, implying well over 2.5 million people newly infected.

An additional increase from around 10% in mid-April to 20% next year of the population are projected to be “protected after infection and vaccination” – indicating a 10% increase in immunity due to both a combination of continued infections and vaccination.

A final version of this model dated 5 May explains that it attempts to estimate: “The degree of past infection over the course of the UK epidemic from January 2020. This determines the proportion of people who will have natural immunity due to prior infection.”

It offers a revised version of the graph on projected immunity, once again predicting a rise in the percentage of the population being “protected after infection” as well as “after infection and vaccination” – but extending this period all the way from the summer of 2021 through to June 2022, implying continued COVID-19 transmission contributing to the accumulation of immunity during this timeframe. 

In this final scenario, the role of continued COVID-19 transmission is expected to contribute to just over 35% of overall herd immunity by next summer, a slight downwards revision from the initial scenario.

The two other Government-commissioned models dated 5 May by the University of Warwick and the London School of Hygiene & Tropical Medicine (LSHTM) also incorporate the role of natural infection in contributing to herd immunity. Unlike the SAGE document dated 7 February, the texts of all these papers avoid the specific phrase ‘herd immunity’.

The LSHTM model, however, is the most explicit in setting out a scenario in which the easing of restrictions in April leads to a rise in transmission which then declines not just due to ongoing vaccination, but also specifically due to the “accumulation of immunity in the population… through natural infection”:

“The easing of restrictions is expected to lead to a rise in the reproduction number which is expected to be above one. The half-term school holiday in May/June 2021 results in a temporary reduction in the reproduction number. The gradual decline thereafter is due to accumulation of immunity in the population, largely through vaccination but also through natural infection.” [emphasis added]

In May, a SAGE summary of these models concluded that any such resurgence is primarily “due to some people (mostly children) being ineligible for vaccination.”

Questions for the Government

While the Government categorically denies that achieving ‘herd immunity’ through increasing infections is part of their pandemic planning, the scenarios described in these SAGE documents do appear to echo a public statement in January from Dr Mary Ramsay, Head of Immunisation at Public Health England (PHE).

As Byline Times previously reported, she told the House of Commons Science and Technology Committee earlier this year that the UK will need to “allow the disease to circulate in younger people where it’s not causing much harm” while protecting “the people who are really vulnerable”, if the vaccine fails to sufficiently slow or prevent transmission of COVID-19.  Dr Ramsay denied she was suggesting a herd immunity strategy

In early June, SAGE member Professor Calum Semple openly advocated the possibility of deliberately infecting children, tweeting that: “There might (I stress might) also be good long-term immunological reasons for permitting wild-type SARS-CoV-2 infection in childhood, when there is far less susceptibility to severe disease, though there is still uncertainty about the risk of long covid.”

Byline Times spoke to pandemic expert Professor Yaneer Bar-Yam, president of the New England Complex Systems Institute and co-founder of the Covid Action Group about the implications of these UK Government documents. 

“The idea of ‘herd immunity’ by natural infection to limit the pandemic by sacrificing health and lives is counter to ethics, common sense, and science,” said Bar-Yam, who has advised the UN, Centers for Disease Control, the White House National Security Council, among many other agencies. He is concerned that “the UK Government decision to remove masking requirements in schools, which was strongly objected to by scientists” still increases the risk of severe disease and hospitalisations, and the dangers of ‘long COVID’ which can lead to “long-term effects that are debilitating in a significant number of even mild cases.”

The UK Government has strongly denied there is any policy to increase infections.

The Danger to Young People

In the UK, Office for National Statistics data shows that 12.9 percent of children between 2 and 11 years old, and 14.5 percent of children between 12 and 16 years old display symptoms for at least five weeks after their first COVID-19 infection. 

The prevalence of Long COVID could, however, be even higher. A major peer-reviewed study of Long COVID in children published in April in Acta Paediatrica examined 129 children aged 6-16 years old diagnosed with COVID-19 between March and November 2020 at a single hospital in Rome, Italy. The study found that: “More than a half of the children assessed during the survey reported at least one symptom” lasting more than 120 days, with 43% experiencing at least one symptom over 60 days after infection. Symptoms included “fatigue, muscle and joint pain, headache, insomnia, respiratory problems and palpitations.”

According to Dr. Deepti Gurdasani, “The Government has created conditions that have fuelled spread of the virus, with many children not even allowed to wear masks in schools even if they want to, no attention to ventilation, or any other mitigations… despite being fully aware of the risks. We know that infection rates… are the highest in primary school age groups, and have been driving pandemic growth.”

Gurdasani is a co-signatory among 14 scientists of an open letter to Education Secretary Gavin Williamson published in the British Medical Journal, accusing the Government of “gambling” on risking the spread of COVID-19 in schools by running controversial trials that do not require pupils identified as contacts of a confirmed case to self-isolate, instead doing daily lateral flow tests using Innova devices – which were recently rejected as a “risk to health” over performance issues by the US Government’s Food & Drugs Administration. The letter notes that lateral flow tests performed by individuals without properly-trained testers often produce false negatives, which means they would likely miss many positive cases allowing the spread of disease.

Meanwhile, Public Health England has repeatedly delayed the release of data on COVID-19 transmission in schools, apparently under high-level political pressure

A Government spokesperson said: “Our approach has always been to protect the NHS, save lives, and ensure as many people as possible are vaccinated and protected against this virus.

“The education and wellbeing of young people has always been our priority, which is why we have done everything we can to ensure children can return to school safely, with robust protective measures in schools including twice weekly testing to protect students and prevent transmission.

“We continue to follow clinical advice from the independent Joint Committee on Vaccination and Immunisation on our vaccination programme and have prioritised vaccinating those most at risk of severe illness and death, which were the oldest and most vulnerable people. With over 14,000 lives saved so far, we are now able to extend the offer of a vaccine to all adults but no decisions have been made on vaccinating under 18s.”

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