I’m an epidemiologist. When I heard about Britain’s ‘herd immunity’ coronavirus plan, I thought it was satire — it’s hard to imagine a more damning essay title, and yet this is exactly what epidemiologist William Hanage told The Guardian.

His criticism wasn’t unique. Richard Horton, chief editor of The Lancet (one of the most respected medical journals), has sharply criticized the UK’s strategy and repeatedly asked access to the models which recommended this type of action.

In Ireland and most of Europe, strong gazes were pointed at the British. Did they know something no one else did, or were they just wrong? Now, the latter seems increasingly possible.

Bad communication, or just bad science?

Ever since the UK announced its strategy, it was clear something was unusual. Mitigation and herd immunity were the key talking points — not suppression.

The UK was on to something. This is, from all we know now, a long fight ahead of us. It’s a marathon, not a sprint, and the best course of action is not to prevent damage — but to reduce it. In this regard, Britain was spot on.

It also makes sense to analyze things before shutting everything down. If this really will last for months and months, is it realistic to expect everything to essentially be shut down for the period?

This is not a simple question to answer, and not one that can be answered without looking at some hard stats. In its defense, that’s what the British government did. Prime Minister Boris Johnson appeared on national television, flanked by two of the country’s foremost experts, and announced that the country will focus on developing herd immunity. The coronavirus will kill people, and the best course of action, they said, was to control as much as possible the way the virus was spreading, protecting the most at-risk people.

So then, why not shut everything down as quickly as possible?

Because, they argued, people are not robots. You can’t expect people to stay cooped up for months; and when the situation really gets bad, that’s when you want to really impose quarantine. Also, if you quarantine now, you’ll have a second wave of infections.

These were the main arguments, communicated imperfectly at best. Under heavy criticism from both scientists and civil society, the government took refuge under “this is what the models are telling us.”

The measures, they argued subsequently, are science-based, and the best long-tern course of action. But communication wasn’t the biggest problem.

“Criticism of the UK government is not, as is being reported, about its communications. The concern is about the strategy to protect the health of the public from SARS-CoV-2,” wrote Richard Horton, editor-in-chief of the Lancet on Twitter.

The UK is obviously not the only country carrying epidemiological and sociological models. There’s also nothing to suggest that the UK’s population is fundamentally different in a demographic way from others.

So then why were the UK’s models producing such different outputs to those in other places? We don’t really know. Horton and other prominent researchers have urged the government to share the scientific data and models used to devise the strategy. But all that was shared so far was the conclusions and reports — not the input parameters and models that were used to get these figures

Then, on Monday, things seemed to change.

A “new’ old strategy

It was on Monday, 16 March, that scientists advising the government called for a “new” strategy to suppress the virus. The new strategy? Pretty much what other European countries had already been doing.

“In the UK, this conclusion has only been reached in the last few days,” the report explained, due to new data on likely intensive care unit demand based on the experience of Italy and Britain so far.”

“We were expecting herd immunity to build. We now realise it’s not possible to cope with that,” professor Azra Ghani, chair of infectious diseases epidemiology at Imperial, told journalists at a briefing on Monday night.

The change of strategy was based on a report coming from Imperial College in London, from one of the research groups that had advised the government. The report not only concludes that a long-term suppression strategy produces better results, but also confirms that UK’s demographic situation is not unique: the same findings are equally valid for the UK and US population.

Essentially, researchers looked at three major approaches:

• doing nothing;
• mitigation;
• suppression.

The first one, it’s clear by now, is a recipe for disaster. Simply doing nothing is a surefire way to overwhelm medical systems and condemn many people that could be saved. If the UK did nothing, 81% of people would be infected and 510,000 would die from coronavirus by August.

The mitigation strategy — which the UK initially opted for — is better. However, it would still result in about 250,000 deaths and completely overwhelm intensive care in the country.

The most viable strategy, the report concludes, is suppression. This will require a “combination of social distancing of the entire population, home isolation of cases and household quarantine of their family members”, and “may need to be supplemented by school and university closures”.

This is, essentially, what happened in China, Italy, and several other countries hit by the outbreak.

Why this change of heart?

Many claimed that the science has changed. However, this is not likely to be the case.

“The science has been the same since January. What has changed is that govt advisors have at last understood what really took place in China and what is now taking place in Italy. It was there to see,” Horton wrote on Twitter.

It’s more likely, Horton argues, that the government advisors simply ignored or downplayed warnings coming from China.

Furthermore, the fact that this change of strategy (which includes tighter measures) came just a few days after the initial ‘herd immunity’ announcement raises even more question marks. If the rationale for delaying measures is focusing on people’s psychology, and we’re expecting closures that can last for months, then what difference can 3-4 days really make? Again, we’re not really sure. Defenders of the approach argue that this is all part of the plan and progressive roll-out of measures. Critics say the government realized it made a mistake.

Whatever the case may be, the UK is preparing for an “intensive intervention package” that will have to be “maintained until a vaccine becomes available (potentially 18 months or more)”, the report said. This paints an extraordinary picture of what life in the UK might look like for the next year, and is also an important warning for other countries: this will almost certainly not end within weeks.

In the case of quarantine, the UK’s concerns were valid: what if we quarantine everyone now, and people stop listening to quarantine, and we have another surge of cases in a few months? That is possible; we don’t really know how effective long-term quarantine is, and there are cultural factors to consider here. But delaying the disease, “flattening the curve” to give the medical system the best fighting chance, is vital. There is no clear-cut solution, and no model is perfect at this point.

Lastly, aside from the actual strategy, there is a point to be made about the clarity of communication. The countries that seemed to have the best approach against COVID-19 (South Korea, Taiwan, Japan) focused on clear, transparent, and straightforward communication. Daily briefings are crucial, and because social action is so important in this case, any strategy can only work as long as its citizens stand by it. Controversies and changes can only make things worse.