“NEVER believe anything until it’s officially denied.” Seldom has Daily Worker journalist Claude Cockburn’s famous dictum been more apt.

Speaking on BBC Any Questions earlier this month, Justice Secretary Robert Buckland said: “I do take issue with this idea that at any stage herd immunity was part of the [government’s] plan. It wasn’t.”

His claim reiterated Matt Hancock’s denial in the Sunday Telegraph on March 15. “Herd immunity is not a part of” the government’s plan to deal with coronavirus, the Health Secretary asserted. “That is a scientific concept, not a goal or a strategy.”

In case you are unsure of the term, the New York Times explains: “The concept of herd immunity is typically described in the context of a vaccine. When enough people are vaccinated, a pathogen cannot spread easily through the population and transmission will be stopped in its tracks.”

In terms of the coronavirus, herd immunity would be achieved by a large majority of the population getting the virus and gaining immunity.

Contrary to the claims of Hancock, Buckland and the rest of the government, there is voluminous evidence herd immunity was a key part of the government’s plan.

“Well-placed government sources said on the strictest reading of the word ‘policy’” the government’s denials “may be true,” a recent Guardian investigation reported. “But they do not understand how the government can claim that herd immunity was not part of its plan.”

On March 13 the government’s chief scientific adviser, Sir Patrick Vallance, told BBC Radio 4 Today programme that one of “the key things we need to do” is to “build up some kind of herd immunity so more people are immune to this disease and we reduce the transmission.”

The same day Professor Graham Medley, who leads the government’s disease modelling team, told BBC Newsnight: “We are going to have to generate what is called herd immunity … and the only way of developing that in the absence of vaccine is for the majority of the population to become infected.”

These statements followed Boris Johnson’s now infamous appearance on ITV’s This Morning when he floated the idea of herd immunity.

“One of the theories is, that perhaps you could take it on the chin, take it all in one go and allow the disease, as it were, to move through the population, without taking as many draconian measures,” the Prime Minister suggested.

According to a Sunday Times report, at a private event in late February, Dominic Cummings, the Prime Minister’s chief adviser, outlined the government’s strategy at the time in a way that was summarised by someone present as “herd immunity, protect the economy and if that means some pensioners die, too bad.”

Considering that the enormous amount of evidence highlighting herd immunity was central to the government’s response to the outbreak, the obvious question is: why is the government so keen to deny this?

Their disavowals are almost certainly because of the two huge problems with herd immunity. First, achieving herd immunity with Covid-19, which was estimated to have a mortality rate of 0.3-1.0 per cent in the Lancet medical journal on March 21, means a huge number of people dying in the process.

This was highlighted when Vallance was interviewed on Sky News on March 13. He confirmed government policy was to try to “reduce the peak of the epidemic, flatten it and broaden it, so that you don’t end up with so much intense pressure on healthcare systems at one time.”

When he explained 60 per cent of the population would need to get the virus to achieve herd immunity, presenter Stephen Dixon responded: “Even looking at the best case scenario … 0.5-1 per cent fatality in something like this, that’s an awful lot of people dying in this country.”

With Britain’s total population at approximately 67 million, herd immunity would lead to around 200,000-400,000 deaths, according to these assumptions.

Vallance went on to note that Covid-19 was likely to become a seasonal virus, highlighting the second serious problem with the government’s herd immunity strategy: it is still unclear whether people who contract Covid-19 gain a sufficient level of immunity to protect them from catching it again.

This was well understood in March, with World Health Organisation (WHO) spokeswoman Margaret Harris telling the BBC Today programme on March 14 “We don’t know enough about the science of this virus, it hasn’t been in our population for long enough for us to know what it does in immunological terms.”

On the same day the British Society for Immunology published an open letter to the government making the same point, noting “we don’t yet know if this novel virus will induce long-term immunity in those affected as other related viruses do not.”

To summarise: the government pursued a strategy that it understood would lead to hundreds of thousands of people dying, even though there was no evidence the plan’s main aim — immunity for a large majority of the population — could be achieved.

Beyond this criminal negligence, worryingly there have been suggestions the government’s herd immunity plan has continued beyond the national lockdown announced on March 23 — a suppression strategy seen as a shift away from the previous plan.

Writing in the Guardian on April 3, Anthony Costello, Professor of Global Health and Sustainable Development at University College London and a former WHO director, argued: “The government and its advisers are now committed to their strategy of delaying the spread of coronavirus, which they hope will eventually lead to herd immunity.”

Devi Sridhar, Professor of Public Health at the University of Edinburgh, was also unsure of the government plan on April 21. “Has the goal been to bring down number of infections & hold it down?” she tweeted, “or to let these increase/decrease in line with healthcare capacity & have the virus go through population slowly?”

Appearing on BBC Any Questions on May 1, Costello said that it was still not clear whether the government was “going after really aggressive suppression … or whether it was trying to manage this and just flatten the curve.”

This confusion, he argued, was likely down to “a split at the top,” with Hancock and ex-health secretary Jeremy Hunt supporting aggressive suppression, while some of the government’s scientific advisers resigned to the virus being “a big problem for the next two years.”

News reports also suggest that the Cabinet is split when it comes to ending the lockdown, with Hancock and Johnson taking a more cautious line and Michael Gove, Rishi Sunak, Priti Patel and Dominic Raab favouring lifting the lockdown sooner rather than later.

These differences within government provide an opportunity for activists, civil society and concerned citizens to exert influence on the government during this extraordinary time.

We know the government and wider Tory Party are very concerned about public opinion at the moment, with “one senior MP” noting “the party would be watching the polls closely,” according to a April 2 Guardian report.

More importantly, on April 18 the Telegraph published a telling quote from a “Cabinet source” about the government’s so-called “exit plan” from the lockdown.

“It [the government] is waiting for the public to change their mind,” they noted. “We didn’t want to go down this route in the first place — public and media pressure pushed the lockdown, we went with the science.”

So, it seems, public opinion has already had a huge impact on government policy, playing a key role in forcing the lockdown on a reluctant government initially committed to achieving herd immunity — a shift that has almost certainly saved thousands of lives.

Indeed, with new daily cases still very high and the government’s testing and tracing efforts not fully established, lifting the lockdown now would be incredibly dangerous.

In terms of the herd immunity controversy, an independent public inquiry seems the natural place to investigate what role it played in the government’s strategy.

With the Covid-19 likely to be with us for many months to come and a second wave of infection and mass death a real possibility, an early and nimble inquiry could provide essential lessons on how to best fight the virus going forward.

Follow Ian on Twitter @IanJSinclair.