"COV-erview" of the latest COVID-19 wave

Reporting has gone quiet on the “Covid front”, largely because of what’s been happening on the “Russian front” in Ukraine. But a quick glance at the “daily dashboard” or the Office for National Statistics breakdown reveals that cases are at an all time high: roughly one person in every 15 is infected. So, as further booster doses begin to roll for the over 75s, adults in care homes and anyone over 12 with an immune problem, we thought it was high time for a Covid update - a “cover-view” if you will - to explore what’s happening and why, whether the current - very much hands-off - approach to management of the pandemic is the right one, and what the future likely holds. Chris Smith spoke to Paul Hunter, who is an infectious diseases specialist at the University of East Anglia…

Paul - The problem at the moment is that a diminishing proportion of people who are infected are actually going for a test. For England, for most of the pandemic, we've been picking up about 40 to 45% and, in the most recent data from the ONS, that was down to about one in eight.

Chris - So, in other words, there are eight times more infections out there in the community than the tests currently being reported suggest.

Paul - Yes, and probably a bit more than that as well.

Chris - The numbers that are being suggested are already pretty high. I mean, if you look at the government's daily dashboard, and then you look at what the seven day average would suggest is the daily rate, and you times that by eight, that's a stupendously high number.

Paul - It is. And this week it is almost certain that the number of real infections that are going on in the community are as high, if not higher, than they have been at any time in the pandemic.

Chris - Now what's underpinning that. Is that, as Chris Whitty and Patrick Vallance said at the Downing Street briefing, when they unveiled the withdrawal of a lot of the measures, just because more people are going to meet more often? So we're expecting more cases or is there more to it?

Paul - I think there's more to it. There was a huge Omicron wave around the world, and there is now a subsequent second wave going on. That second wave is due to the sub lineage of Omicron, the BA.2. That's the thing that has been increasing in the UK since Christmas. But, on top of that, from about the 1st of March, we also saw that increasing and accelerating. That was almost certainly due to behavioural change, partly due to relaxation of the remaining rules and probably also as well because people are mixing more over the last few weeks.

Chris - Is it translating into more severe disease, though? Or are we seeing cases, but not seeing consequences?

Paul - We're seeing hospitalisations rise. The issue is, at the moment, a lot of that increase is in people who are in hospital with COVID rather than because of COVID. In over half of all infections in hospital, the infections are not the reason for the person being in hospital. It's an incidental finding.

Chris - In other words, you've got loads of disease in the community, people are going to continue to have heart attacks and strokes at the same rate they always have. So, inevitably, if you've got lots of COVID about, you're going to be admitting people who also have coronavirus.

Paul - Indeed.

Chris - If we look at perhaps the most sensitive measure of severity, which is how many people are on ventilators, that number appears to be lower than it was last July when we were busy opening up the country saying, right, freedom day is finally here, we've got far fewer people in intensive care beds. It's about 200 or so, we had double that number last year.

Paul - Absolutely. That's starting to drift up a little bit because of the number of infections. But you're quite right, the proportion of people in hospital who are actually in an intensive care unit bed is substantially lower than it has been throughout the entire. There are signs that the infection isn't being as severe as it has been in the past and you can see this in various other metrics, however you want to play it out, that the proportion of people who die is lower than it's been throughout the pandemic and it's probably lower now than you would expect to see from seasonal influenza.

Chris - So are we managing this the right way at the moment in your view?

Paul - There's a lot of issues going on here. The first is that we do know that immunity to infection wanes after vaccine, or even after an infection, you can get another infection, although generally those second infections are less severe. The concern that I have is that the longer you leave it between infections, the less protection you have against severe disease. We see this with influenza. If you live on a remote island and you experience flu once every 10 years, then you often have higher fatality rates than when you get it where flu circulates every year. So, there is an issue here about how long is the best amount of time to apply these sorts of measures. I was only today, actually, reading some reports going back to 2006 by a World Health Organization working party on influenza control measures and, basically, the point that they were making was that a lot of these measures never prevent spread ultimately, but they delay it. And early on in the pandemic, delaying the spread was really important, partly to protect the health service otherwise it would've been overwhelmed, but partly because if you were able to delay an infection until the autumn, we knew about dexamethasone, our intensive care specialists were much better at keeping people alive. Then, of course, if you were able to delay your first infection or first exposure until 2021, when we had vaccines, then you were much less likely to die. But, once you've got all those benefits and nothing else is coming along, then actually the value of continuing restrictions becomes a lot less. The balance between the harm that these sorts of restrictions can do to people's mental health, to the economy, and all these other things related to the benefits in terms of reducing spread of infection starts to shift.

Chris - Do you foresee that we will manage this in the future a bit like we do the flu where we've got this international surveillance system running, we watch what the flu does, we try to preempt its next move and we bottle that in a vaccine, we give that to vulnerable people in the autumn, and we hope we've protected them for long enough for the flu to come through a country and then exit the premises, leaving behind people who may have had a brush with it, but they've been okay? Is that probably what we're going to do for COVID?

Paul - To a large extent, yes. Over a year ago, Nature magazine did a survey of leading infectious disease researchers, and the vast majority of them accepted that this was going to be endemic, was going to cause infections repeatedly. But, over time, as people's immunity built up from both vaccination and natural infection, the disease itself would get less and less severe and become more mild. And, in fact, that's what we're seeing. Interestingly, we're in a situation now with Omicron, the value of vaccine is to actually help make sure you survive your first one or two infections, and after that, your immune system will make sure that although you will still get infections, they won't actually put you at risk.

Chris - Let's hope it stays that way. Paul Hunter, there.