Common Cold Clarity

In the midst of this fourth wave, and my being on staycation, I’ve been enjoying some nature walks and sitting off in nature. On one of my walks I passed two people also sitting off by the water, beer in hand, discussing the current outbreak. Beyond the usual pleasantries I didn’t join the conversation, mostly because it was hot and I was thirsty. Nonetheless, I thought it useful to address the key question that seemed to be animating their conversation.

Basically, they were discussing the fourth wave and whether or not to get the vaccine (they were both I’d guess in their 20s). One of them said he didn’t trust the vaccine because the common cold was caused by a coronavirus, and there’s no vaccine for that, so he didn’t trust that the vaccine for covid-19, a coronavirus, was legit. So, let’s explore that…

Is the common cold caused by a coronavirus?

As is often the case in science/medicine the answer is nuanced. It’s not a straight up yes or no. In this case the answer is ‘sort of, can be, but…’

Despite us all collectively referring to it as a single illness ‘the common cold’, what we’re actually referring to is the symptoms of an illness that can be caused by about 200 different viruses. As all of these can cause the same symptoms, we generally don’t discern between them in common conversation. Indeed, only researchers studying them really bother discerning between them. Your doctor is as likely as a random person on the street to simply call it the common cold.

Okay, so back to these 200 different viruses that can cause what we call the common cold. Of these, some are, indeed, coronaviruses, relatives to covid-19 (or SARS-CoV-2). However, the vast majority of these viruses (around 180 of the 200 or so) are not coronaviruses but actually a type of virus known as a rhinoviruses (which means, roughly, ‘virus of the nose’ which kind of indicates where you’re most likely to find them…). Of the remaining 20 or so viruses that can cause the common cold, in addition to some coronaviruses there are other types of viruses such as adenoviruses and enteroviruses.

So, essentially, some coronaviruses can cause the common cold, but most common colds are actually caused by rhinoviruses. In theory, after many years (decades, probably centuries or more), covid-19 will become a coronavirus that causes the common cold, but at the moment it is novel to our immune systems, which is why it’s so problematic to us, whereas the existing common cold coronaviruses are ones our immune system has had millennia of experience dealing with – thus why their symptoms, while annoying, are usually mild (but, of course, can cause complications for some, nonetheless).

Okay, but why don’t we have a vaccine for the common cold?

This is also a question that doesn’t lend itself to a simple answer. It’s nuanced.

The short answer is that we actually do have effective vaccines for many of the viruses that cause the common cold, and we’ve had them for decades. However, because there are about 200 viruses you would need to vaccinate again AND the symptoms of the common cold are generally mild, it’s simply not economical to vaccinate against all 200 viruses. We have enough trouble getting people to get annual flu shots, let alone covid-19 vaccines – can you imagine trying to encourage people to get 200 annual vaccine shots? It’s just not happening.

Now, that being said, if one could create either a vaccine that focuses on something universal to all the rhinoviruses that cause the common cold, so you just need one vaccine and you’re good for 180 out of 200 of the viruses, that would be economically viable. Or you can create a single vaccine which includes in it the individual vaccines for tens of the common cold viruses, that, too, would be economically viable.

And researchers are, indeed, working on both of those possibilities. At the moment the ‘holy grail’ approach of a universal rhinovirus vaccine isn’t anywhere close to happening, but some working vaccines capable of vaccinating against up to 50 individual common cold viruses have been developed.

Still, there’s a lot of hurdles to make these approaches economically viable, and as the common cold in general is a mild illness and while it does have an economic cost to society (in capitalism measured in terms of loss of productivity) of about $40 billion annually, the investment needed to vaccinate against ‘the common cold’ is more prohibitive. Covid-19 however has an economic cost (in it’s first year) of about $10 trillion, and is caused by a single virus (albeit with variants), making it far more viable an investment for developing a vaccine.

And this is especially so seeing as the coronavirus has long been identified as having the potential for the pandemic we have experienced – remember the 2002-2004 SARS outbreak? It didn’t quite reach the extent that covid-19 has, but was also caused by a coronavirus. And then we had the MERS outbreak in 2012, also caused by a coronavirus. Since them, researchers have been studying coronaviruses and developing vaccines for them. The result? When covid-19 hit we didn’t have to start from scratch. We had about 80-90% of the work already done and just needed to fill in the gaps specific to the new coronavirus. And we poured huge amounts of capital and labour into that task. Which allowed us to produce a covid-19 vaccine relatively quickly.

Key takeaways?

  1. The common cold is caused by any of 200 different viruses.
  2. Some of those viruses are related to covid-19, being coronaviruses, but most (180) are actually rhinoviruses, not coronaviruses, and there’s other types of viruses also in play.
  3. We do actually have vaccines for individual common cold viruses, but it’s not practical to have 200 annual common cold vaccinations.
  4. Researchers are working on workarounds that would be economically viable and practical, but we’re not there yet.
  5. Researchers knew coronaviruses had the potential for creating a pandemic since at least the 2002-2004 SARS-1 outbreak (covid-19 is technically SARS-2) so we’ve been working on the basics of a vaccine for about 20 years – as such, we didn’t start from scratch in 2020 in developing the covid-19 vaccine, even though it was a novel virus.

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