Technology

Dominic Cummings is right: herd immunity was always the government’s Plan A

The argument about the UK’s initial pandemic strategy will test the integrity of its scientific advisers

May 26, 2021
Dominic Cummings arrives for his much-hyped committee appearance. PA Images / Alamy Stock Photo
Dominic Cummings arrives for his much-hyped committee appearance. PA Images / Alamy Stock Photo

I’d not have put Dominic Cummings down as a masterful explainer, given his endlessly meandering blogs. And in his account to the House of Commons Science and Technology Committee on Wednesday, even he admitted that he is an unreliable witness. But his testimony should have made it very plain why he was absolutely correct to have tweeted in advance, regarding the government’s initial pandemic response plan, that “Herd immunity wasn’t ‘a secret strategy’, it was THE OFFICIAL PUBLIC EXPLAINED ON TV/RADIO STRATEGY!”

What’s troubling is that there was ever any confusion about this. Sure, Home Secretary Priti Patel told the BBC’s Andrew Marr on Sunday that it was “absolutely not” the initial plan (leading former Newsnight presenter Gavin Esler to tweet “I’m now struggling to decide which of these saintly figures to believe”). And sure, an inquiry to Downing Street reported by ITV’s Robert Peston on Monday drew the response that “Herd immunity was never the policy.” But are we going to doubt, say, that the first lockdown happened on 23rd March 2020 if the government denies it? (Believe me, Health Secretary Matt Hancock already tried that).

No, the disturbing aspect of this affair is not some discovery that the government had, until 16th March, anticipated seeing the virus spread through the population until we acquired herd immunity. That had always been clearly stated. Rather, it is that we are now seeing an attempt to rewrite the history of the pandemic in plain sight—and the media seems barely even to notice. This is why the “herd immunity” issue matters.

Sadly, it’s no surprise to see ministers doing it. But the collusion of some scientists is dismaying. When asked by Marr at the weekend, Jenny Harries, former deputy chief medical officer and now chief executive of the UK Health Security Agency, attested that she had “never been in a government meeting where herd immunity was put forward as a mechanism of control” for the pandemic. This is a carefully worded obfuscation, abetted by Harries’s qualifying statement that “I would not have been in most of the high-level ones.”

Maybe not, but you’d think she might have watched the telly to see what her fellow scientific advisers were saying back in March of last year. For example, Sage scientist Graham Medley telling Newsnight that “We are going to have to generate what we call herd immunity. So that’s a situation where the majority of the population is immune to the infection. And the only way of developing that, in the absence of a vaccine, is for the majority of the population to become infected.” Or another Sage member, John Edmunds, telling Channel 4 that “the only way to stop this pandemic is indeed herd immunity.” Or the Chief Scientific Adviser Patrick Vallance telling the Today programme on 13th March that “Our aim is to try and reduce the peak, broaden the peak, not suppress it completely; also… to build up some kind of herd immunity so more people are immune to this disease and we reduce the transmission.”

Harries further muddied the waters by claiming to Marr that “herd immunity” has been misunderstood, and that the aim was and is simply to get to that point through vaccination. Her comment looks like a ploy to steer the conversation into territory more congenial to the government.

It’s indeed in the context of vaccination programmes that herd immunity is usually discussed by epidemiologists. That is precisely why talk of it by government scientists, before it was remotely clear we would ever have Covid vaccines, raised so many alarm bells both in and beyond the UK. No one really thought that somehow we would slow down the first wave so much that fatalities would remain low until a vaccine arrived; it would have been utterly reckless to count on that succour ever being available. Rather, the feeling was that we were going to have to get it over with, one way or another: to accept a considerable death toll until we’d reached herd immunity by infection.

So the original plan was clear. The UK scientists worked with the government to develop a plan (though not much of a plan, if Cummings is right) to “flatten the curve.” We would not avoid infections spreading (as a lockdown attempts to do), but merely try to slow the virus so that it might move gradually through the population and not overwhelm the NHS. That way, Vallance explained in early March 2020, you eventually get to a point where there’s herd immunity. He estimated that it might require about 60 per cent of the population to become infected.

But surely, with a virus this lethal, that would still mean a massive number of people dying, he was asked by Sky News. Sadly yes, said Vallance—“We do face the prospect of an increasing number of people dying—this is a nasty disease.” Yet the aim would be to minimise fatalities by sheltering the most vulnerable.

This sounds incredible now—and indeed those few maverick scientists still clinging to this so-called “focused protection” idea are rightly dismissed by the rest of the scientific community. For one thing, who are the vulnerable? Should I, as a 58-year-old man, be grouped as one of them? Or was I expected to take my chances, do my duty, and wait for infection to reach me? Even if you consider just over-60s to be at serious risk, that’s nearly a quarter of the population. So how was that going to work? No one knew, it seems: Cummings told the committee that even by 19th March there was no detailed plan for shielding the vulnerable.

Besides, we didn’t know last March that herd immunity was possible at all. As Sage member and director of the Wellcome Trust Jeremy Farrar told me last summer, we didn’t even know if infected people would be immune, or for how long. We didn’t know the threshold for putative herd immunity with any reliability. In Manaus, Brazil, an estimated 76 per cent of the population was infected by early 2021, yet still with no sign of herd immunity. What’s more, mass infection raises the chance of new, potentially more contagious or virulent variants arising, as we now know all too well.

Given all this, it is hard to understand how “herd immunity” as a strategy was ever contemplated by reputable scientists. One view is that they were too fixated on treating Covid-19 with the strategies developed for a flu pandemic. Cummings regards it as a textbook case of groupthink. At any rate, when a modelling study by Neil Ferguson and colleagues at Imperial College, released on 16th March 2020, showed that even the most optimistic “mitigation” (curve-flattening) approach would incur huge numbers of deaths (perhaps a quarter of a million), prompting an eventual strategic change to lockdown (“suppression”), it was hardly a bombshell. That work simply put in rigorous terms what should already have been obvious.

We now see the truth of that. Even with (botched) lockdowns, 128,000 have died in the UK; even with vaccines, that toll is likely to rise by several thousand before it is over. And yet probably less than 20 per cent of the population has been infected. Imagine the result if we’d gone for the 60 per cent Vallance seemed resigned to in March 2020. 

That initial strategy was, then, terribly misguided. But those were immensely difficult times, and even good scientists make mistakes. None should be castigated for it. But we need an inquiry to investigate how they got it so wrong—and an honest admission that they did.

Was “Plan A” a “herd-immunity strategy”? It’s wrong to try to reduce this to semantics. As Ferguson’s study indicated, there were two basic options. One, being recommended by many experts and adopted in East Asian countries, was to lock down fast and take the economic hit, buying time to find out more about the virus, to improve preparedness, for example with better testing systems and more PPE, to look for antivirals and other treatments, and simply to take stock without mass deaths.

But Vallance and Whitty saw this as just storing up trouble for later. “The entire assumption in Whitehall,” said Cummings, “was… if we suppress it completely, all you are going to do is get a second peak in the winter, when the NHS is under pressure [and] that’s even worse.” What’s more, he says, it was believed “it’s inconceivable that the British public are going to accept Wuhan-style measures”—an East Asian-style response just wasn’t feasible in the UK. This was by no means the only example of the exceptionalism that fatally infected government thinking.

So initially, suppression was rejected in favour of mitigation. The attitude until 13th March, said Cummings, was that achieving herd immunity by natural infection was “a complete inevitability.” (As he attested, no one imagined we could count on vaccines to rescue us in a timely enough fashion.) Of course no one wanted to go through that, he said—but it was absolutely the plan, and “I’m completely baffled as to why No 10 has tried to deny that.”

Mitigation, then, meant trying to slow and control infection so as to reach herd immunity in the population, and end the pandemic, without too many dying. As Vallance explained in the government press briefing on 12th March 2020, the plan was not to stop the virus spreading, because, he said, not only is that not possible but “it’s actually not desirable, because you want some immunity in the population.”

In other words, adopting mitigation rather than suppression in the manner of China or South Korea meant that herd immunity became the goal. If that does not warrant description as a “herd immunity strategy,” what on earth would? And if the chief scientists disagree with that description, they must tell us why.

Vallance already tried to push back on the idea last year, saying that herd immunity was not the “plan” but merely a desired consequence of the plan. But this is disingenuous. It is like saying that I never made London my explicit travel destination; I simply decided to drive down the M1 to its source and my arrival in London was a natural consequence. Hancock has attempted the same ruse. Perhaps Cummings is right to suggest he simply did not understand herd immunity (Cummings seems to feel Hancock understood rather little). That would also be the generous interpretation of Patel’s latest denial.

But why Harries, previously a top scientific adviser and now heading a crucial part of the technical infrastructure, has also tried to deny it, and to confuse the issue to boot, is more troubling. Cummings attributes her previous solecisms—prematurely dismissing mask-wearing, calling the UK an international “exemplar of preparedness” when we patently were not, arguing against starting lockdown “too early”—as the very reasons for her having been promoted to her new job.

If we can’t trust scientists to be honest and direct about this issue, that doesn’t bode well for the eventual public inquiry. But Patel and Harries have placed the government scientists in an invidious position. If they speak out to set the record straight, they risk undermining the government—which at least those who are civil servants must aim to avoid. But if they don’t, then they, and science itself, are compromised. Perhaps Cummings’s testimony will make it harder for them to remain silent—on this, and a great deal else.