Making sense of the coronavirus pandemic— what the science is telling us, and what you can do to prevent its spread

I’m an infectious disease epidemiologist with a background in new and emerging infections, just like this new coronavirus which is currently sweeping the world.

Over the past few weeks I’ve watched as a lot of fear and misinformation has swirled round the internet, and it occurred to me that a lot of it is there because people simply don’t really understand how the science of new infections works, and why the messages we are hearing seem to be changing every day.

I orginally wrote this article as a Facebook post for friends, but was urged to make it public and it has since been shared >1000 times. So I’m adapting it here so that people without Facebook can read and share alike. I hope it helps to demystify things for you. Note that I’m writing about the current situation in the UK, which will be slightly different depending on where you are and at what point in time you’re reading this. I hope you find it helpful.

(Just to note — you can find my CV on LinkedIn; I am writing in a personal capacity and not affiliated with any organisation. The modelling paper referenced is “Report 9: Impact of Non-Pharmaceutical Intervenions to reduce COVID-19 mortality and healthcare demand” by Ferguson et al at Imperial College, and is available freely online).


More data are in, and the data aren’t very encouraging, sadly. But before I elaborate any further, some background info on what work is being done, both in the UK and internationally, to help stem the tide as much as we can.

In any new and emerging infection, you never know at the start what it’s going to do. You don’t know how good it is at transmitting to other people. You don’t know who’ll be at most risk. You don’t know its fatality rate. You don’t know if people have symptoms before they are infectious, or if they spread it around for a little while before they know they are sick.

Infectious disease epidemiologists are the people who track the emergence in real time, in an effort to work out some rough answers for these questions. We’re also good at looking at what happened in hindsight, which can be used for learning for the future. But in an emerging situation, what you really want to know is not what’s happening right now, nor what happened over the last few weeks: what you really want is some kind of crystal ball to look into the future. And if you want to predict what’s actually going to happen in the future — then that’s for the mathematical modellers.

Mathematical modellers play “Let’s pretend”. They use fancy computers and statistics to input the rough numbers the epidemiologists have come up with so far. They say: “Let’s assume that one infected person is infectious for two days before they stay home feeling sick. Let’s assume that person will come into contact with 20 people in a day. Let’s assume that one case usually leads to two other people becoming sick. Let’s assume that if we implement social distancing, 50% of people will comply with it… Etc etc etc. And then they crunch the numbers and come out with what they think the outcome may be. Remember: these outcomes are based on a *lot* of assumptions (more on that later).

So…using data that the epidemiologists have gathered so far, Imperial College has done some mathematical modelling on coronavirus, and it’s not brilliant news. To start with, the UK’s plan had been to let the virus move slowly through the population, whilst making sure the most vulnerable were protected by self-isolation etc. The strategy was to slow the outbreak down with various control measures, but still let it progress, with the aim that most people would become immune, herd immunity would then protect those more vulnerable to infection, and health service capacity would not be overwhelmed. It was a nice plan and would have minimised the disruption to society that we’re now going to see (more on that later).

However, since deciding on that strategy, more work has been done to quantify exactly what capacity the NHS has, and now this is known and the numbers have been crunched, it looks as though if we were to pursue that strategy, we could end up in the situation where we could potentially exceed the number of ICU beds we need by a factor of eight to one. Or put simply: eight people needing beds, and only one available. And that’s only considering the beds needed for coronavirus. Suffice to say that wasn’t quite the prediction we’d been hoping for.

Given this, you may well be thinking “WHY DID WE EVER PURSUE THIS ROUTE, WHY DIDN’T WE GO ON LOCKDOWN LIKE EVERYONE ELSE FOR GOODNESS SAKE????” And that’s a fair and reasonable question, which I’ll attempt to answer now.

The trouble with lockdown or super strict measures to stop people moving about (leaving aside the catastrophic effects that has on people’s livelihoods and mental health and wellbeing) is that it doesn’t so much get rid of the problem as just put it on hold. We can see the numbers coming down now in China and Italy, but meanwhile the virus is grumbling away under the surface. When those measures are relaxed and people start mixing again, we are likely to see case numbers climbing right on up again. It becomes like a game of cat and mouse. Ultimately, in the absence of a vaccine (a minimum of 12–18 months away), the only way you can bring an end to this game is to get some degree of immunity developing in your population. So it might well end up being to our advantage that we didn’t implement harsh control measures right away. Only time will tell, but it’s good to note that the lead author on this new modelling paper reckons the UK has got the timings about right so far.

So what’s the plan? Well, the modelling has concluded that probably the best way to contain this is a cyclical approach. When numbers start to climb up and hit a certain threshold, we hit pause by implementing strict control measures. Then when numbers start to go down, we relax those measures — but in the knowledge that the cases will again creep up and meet that threshold, and we will need to hit pause again. It suggests that we will need to hit pause for a period of around five months in the first instance, and that we will have to continue to have to implement this cycle of pause-relax-pause-relax-pause-relax for the best part of two years.

In short: this is not all going to go away after a few weeks of shutting schools. Not. Even. Close. Don’t be fooled into thinking that we will have a couple of weeks of lockdown and then it will all go back to normal. This is a new reality, the impact will be huge, and we all need to be looking to the government to support people during this time as businesses will collapse and people will be pushed into poverty. Many of us who have never considered ourselves as “vulnerable” will become vulnerable.

My take-home message is this:

***Coronavirus looks set to fundamentally change the way we live for the medium and probably long term.***

While you let that sink in, here are a couple of positives to hold on to:

First: hitting pause won’t just have the benefit of slowing viral spread — it will also give us a chance to upscale ICU capacity, produce and install more respirators, upscale our testing capacity so it’s easier to find out who’s infected versus who’s just coughing, find treatments that work, develop a “serological” test to help identify people who’ve had the infection and are now immune, etc. It also helps us get a bit further down the road to potentially developing a vaccine.

Second: models are based on a whole host of assumptions. We don’t know how accurate the predictions will turn out to be. Nothing is a definite fact, and the strategy will evolve and become more predictable as more data and information become available. A lot of what is scary and unsettling about this is the uncertainty of it all. Fear of the unknown is not good for our mental health, but the unknowns will reduce as time progresses. All eyes will be on the likes of China and Italy as restrictions begin to be lifted.

Make no mistake that these are unprecedented times, though. How we all react to it will be key to how well we do to contain the virus spread.

So, with that in mind, let’s turn to what YOU can do to help us all get through this.



We need to fundamentally change the way we socialise. It’s going to be very hard because as humans, we are social animals. But we need to seriously distance ourselves from each other now, and especially so if people have underlying health conditions or are older. There is great guidance on how to do this on the government Coronavirus webpages (referenced below). It’s time to start working out ways you can socialise with the people you love and who keep you sane by virtual means (as well as remote working wherever possible). Skype, Microsoft Teams, Zoom, Slack, Facetime, WhatsApp — look into them and find out what works for you.

Note: ***standing in long queues at 8am trying to get hand sanitiser from Superdrug is NOT a good way to reduce your social contacts*** Soap is just as effective (which I’ll come onto in my next point):


You’re still going to have to go out sometimes, e.g. to get food. Channel your inner Holby City surgeon (for non UK-readers, this is British drama series set in a hospital — think Grey’s antomy or ER). Thoroughly wash your hands when you go out, and after that pretend EVERYTHING you touch could have germs on it. You know how they switch off the tap with their elbow? Do that when you’ve washed your hands in public. You know how they bust through the theatre door using their backs rather than pushing a door handle? Do that when you’re entering a shop. Seen how they clasp their hands together as if in prayer when they’re standing by the operating table in order to avoid touching anything? Do that while you’re on the bus. It’s a good way to reduce touching your face, which is really hard to do.

I *cannot emphasise enough* the importance of good hand hygiene. Soap kills coronavirus. So does hand sanitiser, but it’s exceedingly hard to come by at the moment so let’s set it aside for now. All you need is soap and water — doesn’t need to be hot water. Doesn’t need to be fancy soap. Any bar of soap, liquid soap, shampoo, shower gel, washing up liquid — any of those things will kill coronavirus so long as you wash your hands thoroughly with it for 20 seconds.

I encourage you all to set up a bucket of water and a bar of soap next to your front door and make sure anyone who steps across your threshold washes their hands before entry. If you’re out and about, carry a bottle of water and soap with you. Wash your hands like it’s going out of fashion. With soap.


Inevitably we’re all going to want to get out of the house and see some people, or it’s going to be really hard on our mental health. If you are gagging for some social contact — I am stealing these excellent tips from my fellow infectious disease epidemiologist Dr Naomi Boxall to behave as if you’re in a Jonn Le Carré novel: 1) take circuitous routes to outdoor destinations, avoiding those hidden in the crowd 2) meet up with friends on park benches, sit 1m apart facing the same direction 3) communicate enthusiasm of greetings with brooches/hat angles 4) only meet physically with those from similar isolated cells 5) TOUCHING YOUR FACE IS A CODE YOU HAVEN’T YET LEARNED; DON’T DO IT: YOU MAY INADVERTENTLY CONDEMN INNOCENTS 6) remove outerwear as soon as you enter a dwelling, be silent of foot 7) leave no fingerprints 8) hold private discussions under the cover of running hand washing water.”

Note, if you have a new continuous cough or fever, or have been in contact with someone who has, you don’t get to play the spy game for at least two weeks.


Follow the self-isolation guidelines to the letter. Do not assume after a couple of days that you’re fine and start going out again. Stay home. Consult the NHS webpages (link below). Do not call 111 unless you absolutely can’t find the answer to your query online. Absolutely do not call 999 unless it’s an emergency.


Vulnerable people, the elderly and those in self-isolation are going to need those online slots. If you’re young and healthy and you’re a usual online shopper, cancel your slots and instead go in person to the shops (whilst pretending to be a spy and a surgeon).Go at non-peak times and don’t stand in any long queues or crowds. Obviously we know that shelves are running empty, so rather than stocking up, instead just buy a couple of items every day from a different shop each time, including your local corner shops, until the supply chains are a bit more restored. That will mean there’s enough to go round.

Remember that if you hog all the produce and the online slots to yourself, basically what the result will be is a load of people who should be in self-isolation traipsing round town in search of what they need and leaving a big trail of virus everywhere. It is not in your interest.

If you *are* elderly or vulnerable, avoid supermarkets and shops quite literally like the plague — even the special hours that supermarkets have reserved for you, as you need to be avoiding places where lots of people tend to go. Instead, shop online or have a friend or neighbour or Mutual Aid volunteer (see next point) bring you what you need.


Now’s the time for us all to finally get to know our neighbours, at least virtually. People who are vulnerable and who are self-isolating and are going to need help with getting bits dropped off to them. Find your local Covid Mutual Aid group on Facebook, or join Nextdoor and get directed to your local ward/street group there. There is some fantastic community organisation going on that will do a lot to lift your spirits, but bear in mind that there will sadly always be unscrupulous people who are drawn to these networks to prey on the vulnerable, so keep your wits about you.


It’s quite hard to fathom what our high streets and communities might look like in a year’s time. Be creative in how you can continue to support them in new ways, to help see them through this time. It’s encouraging to see the support beginning to come through from the government, but make no mistake this will be a time when many people’s livelihoods lay on the line, so make every effort to support while you can.


It’s also going to be a really hard time for people who were vulnerable to start with. Food Banks are running low on stocks; domestic violence is predicted to increase as people are forced together for long periods in stressful conditions. Think about how you might be able to contribute to enable the extra efforts the voluntary sector will be making to support these people during this time.


This is an evolving situation and the guidance on what we should be doing will be updated every day. Listen out for developments and access the latest guidance at the websites below

That’s all, folks. I’m sorry it’s not better news, but we’re in this for the long haul. Let’s hunker down.

I’m an infectious disease epidemiologist with special interest in zoonoses, new & emerging infectious, One Health, and interdisciplinary public health research

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