Why new restrictions may be needed in Wales as Covid cases rise sharply

Angharad Shaw

It looks as if Covid is back again with a vengeance. Throughout the past three weeks, almost unnoticed by many, including much of the media it seems, cases have been rising sharply. So, what’s going on, and what can be done about it?

Cases are now averaging over 1,500 a day. This compares with just under 650 just three weeks ago, and less than 50 in late May. We are in the middle of the so-called “delta wave”: the B.1.617.2 variant, and currently the world’s most prolific strain.

The reason Delta has been so successful in Cymru, and across the planet, is because of its R0 (reproduction) value. R0 is an indication of how many people will be infected, on average, if one single infected person is put in a population that is wholly susceptible (i.e. no pre-existing immunity). Broadly speaking, the higher R0 is, for a given strain, the more successful it will be, displacing other variants on its march through the population.

There is also a formula for working out the level of immunity required in a population to achieve ‘herd immunity’ levels – beyond which the virus will naturally fade away.

R0 for the original strain was estimated at around 3. For Alpha (the “Kent” variant”) it was around 4. For Delta, it has been estimated at 7. At that value, we require an immunity of around 85%.

That is just about achievable, but very difficult. And, sadly, given the number of people who won’t, or simply can’t be bothered to get vaccinated, the only way we will reach that figure is via a certain amount of infection. It’s unfortunate that we can’t just infect the anti-vaxxers – if only Covid would play game!

But our vaccination programme is not yet complete. There are still people who are willing, or who can yet be persuaded, to be vaccinated. I include those aged 12+ in this, who we know are significant drivers in the pandemic. And until we are at that stage, we are unnecessarily infecting people.

There’s another complication here: vaccines are not perfect. They also appear to become less effective over time, though studies on this are only just coming to light and are still debated. But it does mean that even vaccinated people are able to catch the virus. The chances are they will get a milder form; they are far less likely to die.

But evidence seems to suggest that the chances of Long Covid developing from such “break-through” infections are not significantly reduced. Boosters are going to be needed, and probably quite soon for those who were vaccinated first.

Lag

The situation at the moment is that cases are continuing to rise fast, and no end to this rise is in sight. R (the measure of how many people one single person infects, on average, currently) is around 1.3. R does appear now, in the last few days, to have started to fall. But it has a fair way to go until it reaches 1 – at which point cases start to fall.

And this is happening at a time when the bank holiday weekend is just around the corner, and schools are preparing to return. This could be a recipe for disaster.

Today, the First Minister has said that “the rising cases are not translating into huge numbers going to the health service”, and that is used as justification for not doing anything just yet. But that’s a very poor justification. Hospital admissions and deaths always lag cases. We know well what cases are doing; no-one seriously argues otherwise.

Given that the nature of Covid has not changed, we also know, as sure as night follows day, that deaths will rise over the next few weeks, as will hospital admissions. We can even do rough calculations to estimate what will happen:

We know from observation that deaths lag cases by around two weeks. There have been 17 deaths in the past week. If we take the 7-day average cases today, divide it by the average two weeks ago, and multiply the result by the present number of deaths, we get:

(1550/695) * 17 = 38.

Don’t hold me to that. But it will be in the right ballpark. And that won’t be the peak, because right now, cases are still rising.

And it’s true that we are seeing far fewer deaths now than we were from roughly the same number of cases back in January – roughly a tenth. The moral question then is: how many deaths are acceptable, and how many cases of Long Covid are acceptable?

And to that last point: we still do not understand all the long term consequences of Long Covid. So the question is, how much do we risk on something we don’t understand? It is my personal observation that people who have experienced Long Covid tend to be far more keen on maintaining restrictions than others. And that is no surprise.

Schools

So where are we now? Delta took over as the main variant in Cymru sometime in May, and made steady progress. Cases rose until the end of the school term. Then, within a few days (as I am on record as predicting), cases started to fall. There is no question that schools are a major contributor to the pandemic.

But then something unexpected happened: cases started to rise again. It seems what happened is that people went away on holiday, dropping their guard (after all, Boris had said it’s all over – and I am afraid some of that mentality had reached Cymru too) and brought the virus back with them.

This also explains why we see cases distributed so relatively evenly across Cymru, rather than observing epicentres with a spread out from them, as we had seen in the past. This is something we can see most clearly on the maps produced by Dr Lowri Williams, of Cardiff University.

What happens when schools return? There is likely to be an increase in the rate of rise (R will go up). Indeed, it would be quite surprising if that did not happen. But the peak holiday season will also be over. So what happens a week or so after the start of term, when holiday acquired cases have all come to light, is a guess. R will probably lower again. Cases could even start to fall again, as people travel less. Or the schools could continue to drive cases onwards. We just don’t know, because we don’t have past data to go on; last year at this time, cases were very low.

Measures

There is always a price to pay for restrictions, and we can’t ignore that. Be that mental, financial, physical health, or whatever. And these need to be factored into any decision that politicians make. Unfortunately, politicians are also susceptible to political pressure. In a system that is still very adversarial in nature (despite the Senedd having a better setup than Westminster), an irresponsible opposition party can snipe at moves by the government, knowing they will never have to do anything about it themselves.

Such sniping appeals to some voters, and they know it. Such sniping also, indirectly, causes deaths and suffering. Politicians using Covid for political gain in this way should be utterly ashamed of themselves.

What measures could the First Minister introduce? Here are some of my thoughts:

• School children, when they return, must wear masks. This one, to me, given the situation, is a no-brainer;
• Indoor gatherings should be limited. Covid transmits through the air, primarily. Indoors is where most transmission happens. Super-spreader events appear to be a large part of the problem;
• I’m very sorry, young people, but nightclubs are a huge issue here, and we know that young people have been one of, if not the main driver of the rise during the summer. Perhaps local authorities could be encouraged to license more outdoor events for young people (just an idea).

There’s a big problem here for hospitality. We can’t escape the fact that it contributes significantly. Outdoor spaces – fine. Indoors – not. And I don’t have a simple answer to this.

It goes without saying, I think, that mask-wearing in all public indoor scenarios should be maintained.

And finally, when you have to be indoors, ventilation is key. The message is getting out there, but it’s still not understood by enough people. Leave the doors open, open the windows, ensure air is refreshed constantly.

If, when schools return, you collect your child from school and find windows and doors closed, during the mild weather we hopefully will still be experiencing when they return, ask why. The first couple of weeks of school are going to be crucial.

Dr Angharad Shaw is a lecturer in Computer Science, at Aberystwyth University; her PhD and post-doctoral research was in the field of bioinformatics.