When Will Coronavirus End? WH Asked Two leading Scientists

Women’s Health Magazine, by Roisin Dervish-O’Kane
8th April 2020

Responses to lockdown life, so far, appear to be mixed. While some of the non-essential worker cohort can’t stand it, others are, visibly, making the most.

What’s the party line on when coronavirus will end?

But something the whole country is united on (aside from sincere gratitude for the NHS and how relieved we are to see the return of Professor Chris Whitty on those 5pm briefings) is that we’d really, really like to understand how long this is going to go on for.

We humans like certainty – or, in lieu of that, a rough idea of what’s coming up next. And right now, we have neither.

It’s something that Foreign Secretary (and the hospitalised PM’s de facto deputy) Dominic Raab touched on in Monday’s briefing, saying that it’s too early for the UK to consider an exit strategy for the lockdown.

And sadly, making any sort of prediction is remarkably tricky. The reality is: we’re dealing with a new, complex virus and a bunch of other complicating factors that mean, without a crystal ball, that any degree of certainty is beyond the knowledge we’ve got. But might the scientists with the kind of expertise that leaders the world over are calling on to steer their responses be able to offer us some fresh detail?

To find out, WH tapped up a pair of academics who know the field, for their insight.

When will coronavirus end: what does a public health professor think?

Devi Shridhar is a Professor and Chair of Global Public Health at the University of Edinburgh.

WH: No one seems to be able to say when the Coronavirus outbreak will end. Why?

DS: We have loads of unknowns. We don’t know if the virus will mutate, how long immunity will last in a person once they’ve had the virus or the role of children in transmission, and whether it will be a seasonal virus. With such uncertain data, it’s extremely difficult to predict what will happen in the coming months.

WH: What do you think?

DS: I think COVID-19 is here to stay. My predictions are based on experience and data from past outbreaks (which have usually come from animal viruses spilling over to humans and spreading rapidly), as well as mathematical modelling of the current outbreak.

WH: What’s the worst case scenario?

DS: That we are stuck in endless cycles of lockdown and release while we wait for a vaccine or effective antiviral drug.

WH: Eesh. And the best?

DS: Within the coming weeks it would be that we have a rapid diagnostic procedure in place. That way, we can rapidly test individuals, trace their contacts and only isolate carriers of the virus, as opposed to locking down all of society. After that, it’s the creation of an effective antiviral drug, which doesn’t exist at the moment and, ultimately, a vaccine.

WH: What if a vaccine is developed?

DS: This would be fantastic – provided it’s effective, affordable and available. It would mean we could give this to individuals so they develop the antibodies against it, and are protected from the real virus (a process similar to how the MMR vaccine works). But scientists are split about whether it’s possible to create a vaccine that will remain effective long-term.

Kit Yates is Senior Lecturer at the University of Bath and author of The Maths of Life and Death: Seven Mathematical Principles That Shape Our Lives

WH: How are people predicting the outcome of Covid-19?

KY: One way is by using mathematical models. In theory, these tell us how many people will get the disease and how many people will die. They can tell us the impact of lockdowns, how long they should last and what will happen when we start to lift the restrictions.

WH: What’s an example?

KY: One of the simplest models for predicting disease outcomes splits the population into three basic categories: people who have not yet had the disease; people who have caught it and can pass it on; those who have had the disease but can no longer pass it on (whether because they’re immune or because they’ve died). It’s called the S-I-R model.

WH: Got you. So, does it work?

KY: Mathematical modelling in the real world [as opposed to the lab] is always a difficult challenge, as it’s often hard to get good data. In order for the above model to work we’d need to know: how long people are infectious for; how easy is it to pass the disease between people; what proportion of people who have the disease will die from it or have serious complications and need to be hospitalised.

WH: How long do you think Covid-19 will last?

KY: I’ve not done my own modelling, but a team of epidemiologists [scientists who specialise in diseases and how they spread – none were available to contribute to this piece] at Harvard University have suggested that to get through this pandemic, without having so many cases that health services are overwhelmed, we will need to go through alternating periods of tightening and loosening lockdown restrictions. They suggest that this cycling could last until 2022.

WH: Obviously that changes if scientists develop a vaccine, though.

KY: Yes, we could wipe out the disease very quickly if we could vaccinate enough people to give the population ‘herd immunity’ – the theory that a population of immune individuals can slow, or even halt, the spread of the disease. Unfortunately, though, it seems like a vaccine against Covid-19 will be at least 18 months away.

WH: Do you have a ‘best case scenario?

KY: Well, the Oxford study suggests that one situation consistent with the data is that 68% the population have already had COVID and have been largely asymptomatic.

If this was the case – and everyone who had the disease developed immunity– then we would be close to if not at the herd immunity threshold, and could release lockdown soon. They stress that this is just one possible explanation of the data and that it’s based on some unfounded assumptions so is likely not the case, but this is probably the most optimistic that modelling predictions get.

If anything, it highlights that more data is needed in order to be able to distinguish between different modelling scenarios. And that we need the antibody test in order to find out what proportion of the population genuinely have had the disease.

The bottom line? That, basically, there isn’t a new one. Except for knowing that while some of the world’s sharpest scientific, mathematical and medical minds are across solving the greatest health crisis of our time, your – our – duty is to stay home.