The virus is exploiting our very humanity. We are social creatures, but this disease risks turning our natural instincts into a fatal weakness.
Our old routines and habits must be replaced with new customs and practices. We need to adjust to the etiquette of an epidemic.
So how should we behave? How can we be pro-social in a world where a comforting hand or a hug are considered anti-social or even reckless?
In normal times we look to calm anxiety and stress with the human touch. But these are not normal times. The human touch may be the enemy.
Every object we and others come into contact with may be a vector for the virus. The right thing to do is deny this cruel bug the chance to spread.
"This is the time in your lifetime whereby your action will save somebody's life," Prof Stephen Powis, medical director at NHS England, said on Saturday.
None of this comes naturally. It is not easy. We can only do what is possible and we will never know, but the simple act of washing your hands properly may actually save one, two, 50 or 10,000 lives. We should think of that as we sing at the sink.
We are having to learn to do things that feel discourteous, that once might have been thought of as rude. But social distancing, trying to stand at least 2m apart from anyone you encounter, not shaking hands or embracing a friend, these are the new manners of our times. And we need to learn them fast.
The way we all behave during this epidemic will decide the fate of millions. That is why behavioural science is at the heart of the UK government's planning.
The encouraging news for humanity is that the experts believe most people want to do the right thing for wider society. "Acts of altruism will predominate," the Behavioural Science Sub-Group advises ministers. "Large-scale rioting is unlikely. It is rarely seen in these circumstances."
Social breakdown does occur, of course, sometimes driven by fear but also by thoughtlessness and greed. Panic feeds on itself as people struggle to balance their own needs with those of others when the world feels an increasingly dangerous place.
That is what is driving anti-social stockpiling, people "selfishly shopping" as Prof Powis described it.
The behavioural scientists are telling the government to "promote a sense of collectivism".
"All messaging should reinforce a sense of community, that we are all in this together," the advice reads.
It is telling, perhaps, that countries with a collectivist culture - China, Japan, South Korea - seem to be keeping the virus at bay more effectively than those Western nations with a culture of individualism.
"I know how difficult this is, how it seems to go against the freedom-loving instincts of the British people," the prime minister told the nation as he closed down pubs and restaurants on Friday, urging people not to go out.
Small-state politicians like Boris Johnson are having to adjust to the necessity for ever greater central control, actions that may feel at odds with the traditions and culture of the UK.
A member of the scientific committee that briefs senior government ministers told me that this virus will be a measure of "social capital" in every country of the world, the strength of the glue that holds communities together.
We are already seeing a wave of altruism and charity sweeping across neighbourhoods and social media, people looking for ways to support others through the isolation, the hardship and the distress.
The country is having to think differently about what "coming together" means in the context of social distancing. But most of us can look to help others by offering accurate information and advice, delivering food or other vital supplies to vulnerable individuals, befriending and supporting those who may be lonely with a phone call or a friendly text.
Many people stuck at home may have the time to explore the opportunities for building up our stock of social capital, supporting a neighbour, helping out, doing the right thing.
"Now more than at any time in our history, we will be judged by our capacity for compassion," Chancellor Rishi Sunak told the country on Friday. "When this is over, and it will be over, we want to look back on this moment and remember the many small acts of kindness, done by us and to us."
The charity Action for Happiness has produced a "coping calendar" to help people keep calm, stay wise and be kind.
"Do three acts of kindness to help others, however, small," it suggests. Other advice includes calling a loved one to catch up and really listen to them; thanking three people you're grateful to and telling them why; finding positive stories in the news and sharing these with others.
Behavioural science recognises that trust in our leaders is the antidote to anxiety and potential social breakdown. "A perception that the government response strategies are not effective in looking after the public may lead to an increase in tensions," the expert committee is advising ministers.
We need to find new routines and systems for once mundane tasks. A trip to the shops requires we all take meticulous care not to become infected or pass the infection on.
For those who are required to go out to work, the same attention must be applied to everything we touch: handles, rails, keys, coins in a pocket, credit cards in a purse, tins on a supermarket shelf, a steering wheel and a gear stick, a computer keyboard and a mouse, a mug of tea.
It is the responsibility of all of us to minimise the risks to ourselves, our family and the wider community. The disease may be exploiting our humanity, but it is our consideration for others, our compassion and our love for each other which will defeat it.
The next few months will test the strength of our community beyond anything that we have seen in living memory. The demands on all of us are as great or even greater than in wartime. Future generations will judge us for how we behave.