Will the "worst cold ever" come this winter?
As COVID retreats, will it be replaced by an epidemic of coughs, colds and flu viruses? Well, it's already happening, says Ron Eccles, who spent over 3 decades running the Common Cold Centre at the University of Cardiff. Chris Smith caught up with him to find out a bit more about the common cold and whether, in his view, we're all destined to succumb this winter to what some are dubbing "the worst cold ever", and if so why…
Ron - Common cold is one of the most complicated diseases because it's caused by over a hundred different types of viruses. The respiratory viruses, as they are called because they enter the respiratory tract through the nose, are changing all of the time. And we don't have a single vaccine against any of the common cold viruses.
Chris - And that means that you don't have long-term immunity then?
Ron - You have immunity perhaps for a few months, but the immunity doesn't protect you against variations of the virus. The rhinovirus changes its coat so rapidly that we can't really develop immunity to it. There are over a hundred different types of rhinoviruses in circulation at present.
Chris - And is it possible to catch more than one of them at once?
Ron - You can and certainly now that we have such good techniques to identify the viruses, we know now that it's not uncommon to be infected with two viruses, sometimes even three at the same time.
Chris - People are saying we're destined to suffer our worst cold ever this winter. Is that hyperbole, or do you think that there is some risk of that happening?
Ron - I think it's already happening, Chris. During the pandemic, we suppressed COVID, but we also suppressed all those common cold viruses that are transmitted in the same way as COVID. And now we've released from lockdown, we're getting an epidemic of common cold viruses, wherever you look around you, there are relatives and friends and media saying the epidemic of colds are upon us. There is a particularly nasty, common cold virus that is circulating at the moment that tends to cause a lot of cough and chest infection and can have a serious effect on babies and the elderly.
Chris - Why should the fact that we've kept these germs at bay for the last 18 months owing to our response to the COVID pandemic mean that they're coming back with more abandon now?
Ron - Normally we would have these common cold viruses circulating all of the time. They're much more common in winter because our noses are colder in winter and they like a cold environment, but we've suppressed them. And it means that amongst the community, nobody has any resistance to these viruses. No one has been exposed to them and they are spreading very rapidly throughout the community.
Chris - From what you're saying then, in an average year, we catch a cold or whatever, but we've got a sort of baseline level of immunity or resistance then to colds. And because we haven't caught any for the last 18 months as a result, we've lost some of that immunity. And that's enabling these viruses that caused the colds to become more common again.
Ron - That's right, Chris. No one has got any immunity to these common cold viruses. So they've got 100% of the population that they can attack. And in normal circumstances, you know, perhaps 20-25% of the population would have had colds fairly recently. That is why they are spreading so rapidly.
Chris - Is there any evidence that these colds actually compete with each other and could they provide some competition for coronavirus infections? Because there was some suggestion last year that perhaps the common cold might reduce the risk of COVID because your body's busy fighting off the common cold and puts itself into a state where it's harder for COVID to gain a toehold.
Ron - That's correct. We know that there's been a big surge of rhinoviruses when lockdown has been reduced and the rhinoviruses have crowded out some of the COVID viruses. As you say, our immune system is alert, it's activated and it makes it more difficult for the COVID viruses to get in.
Chris - I guess what's interesting is that despite our efforts to suppress coronavirus, these colds - although their numbers went down - they didn't disappear and people have repeatedly come to me during the lockdowns and said "I've taken enormous steps and been very, very diligent about hygiene and everything to stop myself catching COVID, I've still managed to catch colds."
Ron - Well, the colds have been in this game a lot longer than COVID. We've probably been interacting with the common cold viruses for millions of years, and therefore they've got lots of tricks to get past our immune system. COVID will eventually evolve into what I would expect would be like a common cold virus. These new variants are more infectious than the earlier variants and common cold is worldwide all of the time. And therefore it's almost impossible to eliminate the common cold viruses.