Why a Covid-19 vaccine is probably closer than you think

Since the pandemic started, I’ve spent way more time than is healthy reading about it on the internet. I’ve read numerous news articles and discussion threads on all aspects of the Covid situation, and to be honest most of it has been pretty depressing. Everyone wants things to get back to normal in a safe way, but even now that we’re out of the full lockdown, the prospect of that happening still seems quite remote.

A vaccine would obviously be a huge step towards that (maybe even the only realistic way of achieving it), but most of what I read let me feeling despondent about the chances of it happening any time soon. After all, vaccines always take years to develop, don’t they? And even if they manage to do it quicker than that, it’ll mean they’ve cut corners on the safety testing. Anyway, we don’t even know if a vaccine for Covid-19 is possible – there’s no vaccine for any other coronavirus, no vaccine for HIV or for the common cold, and they’ve been around a lot longer. And wasn’t there that story about the guy who got Covid twice? Surely that means it doesn’t induce immunity, in which case how’s a vaccine going to work? Even if we do get one, we probably won’t be able to wipe out Covid – after all, the only virus ever to be fully eradicated was Smallpox and that took decades.

But then, during one of my information-guzzling sessions online, I stumbled across some communities that were very different from what I’d seen before. Communities that were largely made up of medical experts and where posts were strictly moderated to prevent people posting claims that can’t be verified from reputable sources such as academic journals. What immediately jumped out at me was how much more positive they seemed about the chances of a vaccine than most of the general public seem to be. Interested, I kept on reading, and soon discovered that all the pessimistic claims I made in my second paragraph, claims that I’ve seen repeated ad nauseum for months now, are actually untrue (or at least not particularly relevant).

(Or at the very least, the scientists who know most about vaccine development regard them as untrue, which right now is good enough for me).

I thought I would write this post to discuss some of the main Covid-19 vaccine myths and, hopefully, convince you that the picture isn’t nearly as bleak as we’ve been led to believe by ill-informed journalists and commentators. I’m not by any means an expert on this, just an intelligent and interested person who’s done some research and listened to the real experts. As such, if you are an expert on this and I’ve said anything untrue or nonsensical, please get in touch to correct me. If you are interested in doing further, more in-depth reading on this subject, the r/COVID19 sub-reddit is a good place to start.

On with the myths…

Doesn’t it take years to develop a vaccine? And wouldn’t it be unsafe to try and do it in less time than that?

It often takes a long time to develop a vaccine, yes. But this is actually less to do with safety than people think, and more to do with two other factors:

  1. Most of the “easy” diseases have already had vaccines for decades now, so what’s left is the ones that are harder to vaccinate against, and those inevitably take longer.
  2. For the Phase III trials, you have to wait for enough people in your test group to be exposed to the virus you’re trying to vaccinate against, so that you can see whether the vaccine protects them or not. For a rare virus, it can take a very long time for this to happen.

Neither of these reasons applies to SARS-CoV-2 (the virus that causes Covid-19). The reason we didn’t already have a vaccine for it is because it’s new, not because it’s particularly difficult to protect against (based on our current knowledge it seems that it should, in fact, be reasonably easy to produce a vaccine for). And waiting for people to be exposed to the disease won’t take too long in the middle of a pandemic either, because there’s plenty of it going around (at least in some places).

It’s a common misconception that Phase III trials take a long time because scientists are waiting to see if their vaccine causes weird, unexpected side effects years after it’s been administered. In fact, this sort of effect is extremely rare – vaccines do cause side effects, but they typically happen on a timescale of days or weeks. There is not really a plausible biological mechanism for a seemingly safe vaccine to suddenly start causing problems years down the line.

It’s true that certain changes have been made to speed up the vaccine development process, but (at least in the west) these are not things that affect the safety. For example, starting to manufacture millions of doses of a vaccine before it’s been fully tested is obviously a big financial risk that’s only worthwhile because the financial impact of Covid-19 itself is so enormous, but it’s not a health risk at all.

It’s also worth remembering that developing a vaccine in a period of months isn’t actually completely unprecedented – a new flu vaccine is developed every year to target whichever strains seem likely to cause the most problems this season.

We still don’t have vaccines for HIV, the common cold or any other coronavirus. Doesn’t that mean we’re unlikely to find one for SARS-CoV-2 any time soon?

HIV is a particularly nasty virus. It does all sorts of tricks like mutating frequently, hiding within a patient’s own immune cells, and so on, and it can’t naturally be fought off by the immune system. A vaccine is therefore likely to be extremely difficult. SARS-CoV-2, on the other hand, doesn’t do any of that stuff. It’s just a bog standard ordinary virus and there’s no reason to think it’s particularly difficult to vaccinate against.

It’s not completely true to say that we don’t have a vaccine for any other coronavirus – we actually do have vaccines already for some animal coronaviruses. The reason we don’t have any for the other human coronaviruses is less to do with it being particularly difficult and more that it just hasn’t been necessary. The original SARS and MERS were both brought under control through other means before vaccines could be developed, and the common cold coronaviruses are not really dangerous enough to be worth putting in the effort to make vaccines.

Most vaccine candidates fail, so we shouldn’t get our hopes up over the Covid-19 vaccine research.

Most vaccine candidates (about two thirds) do indeed fail… but they mostly fail quite early on in the testing process. Several of the Covid-19 vaccines have already reached Phase III trials, and historically the eventual success rate for vaccines that make it this far is about 85%.

Of course, we can’t take anything for granted yet. It’s still possible that all those vaccines could fall at the final hurdle. But at this point it’s really quite unlikely, especially since they’re based on various different technologies, so a problem that trips up one of them may not affect the others at all.

But do we even know if it’s possible to develop immunity to Covid-19? There were a few people who tested positive twice…

Some people have indeed tested positive twice, but this doesn’t mean that catching Covid doesn’t give you any immunity, or that it’s not possible to induce immunity via a vaccine. Everyone’s immune system is a little different and it’s normal for there to be outliers – for example, most people are immune to chicken pox after they’ve had it, but a few can catch it again. It’s not at all surprising that it’s the same with Covid.

More to the point, although some people are confirmed to have tested positive with Covid twice, I’m not aware of anyone actually having got ill with it twice. This suggests that although the virus was detected in their system a second time, they had enough immunity to prevent it from causing symptoms the second time.

I think a lot of the hysteria about whether immunity is possible or not is due to people not understanding how scientists communicate (and conversely, scientists not understanding how they come across to the general public). We’ve had instances of high profile scientists saying things like “There is no evidence that people develop immunity after having this virus”, and a lot of people freaking out and interpreting this as meaning “People probably don’t become immune after having this virus”. In actual fact, it’s likely the scientists meant something more like “People probably DO become immune after having this virus, because that’s what happens with most diseases and there’s no particular reason to think this one is any different, we just haven’t directly observed it happening yet”. There’s also probably been an (understandable) element of wanting to discourage people who’ve had the virus from disregarding the social distancing restrictions in case it turns out that they (or at least some of them) can still spread the virus even after recovering from it.

Even if we get a vaccine soon, it’s likely to be imperfect, and we’ll still have to live with Covid-19.

Whilst this is true, even an imperfect vaccine could be a total game changer. Even if a vaccine only prevented 50% of infections that would otherwise have happened (either because it was relatively weak in its effects or because not everyone was able to receive it), that would immediately cut the infamous R number in half, making it far easier to control the virus without needing the kind of draconian measures we’ve seen over the past few months.

There’s been a lot of talk about how the Oxford vaccine (one of the current front runners, which could be approved within two or three months if all goes well) didn’t prevent monkeys from contracting the virus, it only stopped them from getting seriously ill with it. Whilst it would obviously be preferable to get complete “sterilising” immunity from a vaccine (i.e. completely preventing people both from getting infected by the virus and from passing it onto others), it’s worth bearing in mind that:

  1. Even a vaccine that “only” prevented people from getting seriously ill would put us in a much better position than we’re in now. It would prevent numerous deaths and hospitalisations and relieve a lot of the pressure the virus has put us under.
  2. It’s fairly likely that people with less severe symptoms would also be less infectious, so they might still spread the virus less than they would have without the vaccine.
  3. The monkeys in the trial were exposed to extremely high levels of the virus, far higher than any person could ever be expected to come into contact with in normal circumstances. It’s entirely possible that, given a more realistic level of exposure, this vaccine might prevent people from catching the virus at all. We just won’t know until the trials progress further.

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