For all the good news that has emerged about Covid-19 vaccines in recent weeks, it is clear that we are not doing a particularly good job addressing people’s reasonable concerns about vaccine safety.
Before we go on though, it is important for you to know who I am, and who I am not. I am a minor academic in a decent university. I don’t normally work on vaccines, have never had any funding from Big Pharma (or anyone else) for vaccine studies, have no career in vaccines and not much to gain from writing this, other than a spike in trolling. I have never met Bill Gates and have no interest in injecting you with a microchip. As someone on my Twitter feed said, I am shilling for 'Big Staying Alive'. So why listen to me? I am experienced in clinical trials, run masters’ courses where I teach students how to dissect clinical trials and, perhaps most importantly, got roped into helping with the Oxford ChadOx vaccine trial, unpaid and on top of my normal job, as the site investigator in Cambridge. In the vaccine debate, I have a ring-side seat without any large stake.
So are the Covid-19 vaccines safe? I was anxious when we started. This anxiety had nothing to do with the safety evidence, which I knew was excellent in general for vaccines. I was anxious because I was the named lead investigator about to take responsibility for hundreds of my healthcare colleagues, some of them friends, being given an experimental vaccine.
Thousands of my most altruistic colleagues across the country volunteered to be guinea pigs so you didn’t have to. They represent the biggest, least-heralded, unsung heroes of the pandemic. We now have 6000 patient years of accumulated safety data as a result of this and, so far, it is excellent. Vaccines are safe. This does not mean they are without risk, but I would strongly argue we know the risks of Covid-19 and they far outweigh the risks of a vaccine. It really is that simple.
However, many people remain hesitant. In particular, there are concerns about the speed with which the studies were conducted and long-term safety of a Covid vaccine. Those expressing doubts about these issues are not anti-vaxxers, and it is important not to shout down people with legitimate concerns. But I'd still say that these concerns, though reasonable, can be addressed.
It's true that the Covid-19 vaccines have been developed quickly, in particular when – as is sometimes claimed – vaccine development can take anything from seven to ten years. But this doesn't mean the vaccine is rushed or unsafe. The reason that many vaccines take so long is rather simple and has nothing to do with safety. Vaccine development involves a hard scramble for funding, dominated by commercial decisions, full of red tape and stupid delays like contract negotiations that drag on for years.
For most of the ten years it can take to develop a vaccine, you are not running a trial. You are not getting safety data. In fact, you would normally end up with a smaller safety dataset than we have in the pandemic because the trials this time around are so blockbuster big. We now know running these trials quickly was 'easy': you just needed unlimited money, all the world’s formidable trial infrastructure pointed at one question, a huge pool of altruistic volunteers and some focused regulators.
Having seen this Covid vaccine developed at close quarters, it was clear that safety was a key consideration. After all, the whole world was watching; every individual potentially important safety event was scrutinised. 100-200,000 people took part in vaccine trials. How many headlines talking about a single possible serious side effect do you remember? One? Two? A handful? This tells you something powerful. I have seen the safety data in our trial, it is excellent and in the coming days you will also get the chance to pore over the data. Please do. Scrutinise our trial and the others. They will be robust.
As for concerns about the long-term safety of these jabs, the honest answer is that we are still waiting, but this isn't a reason to cause concern. If you look at every vaccine developed, you see a clear pattern. Side effects are overwhelmingly short-term (if you want a typical account, see here). This is, after all, built into how vaccines work: one or two doses promote short-term immune responses that primes us for later.
The flu jab is a case in point here: you probably don't even think twice about this when you get your injection. Let's be honest, who has scoured the evidence for flu jabs? I haven't. It is such a non-event, my major question is rather 'Do I do it during the week or the Friday and risk ruining the weekend?'. I expect to feel a bit rough for two days, moan to my wife then get on with life. There is no reason to think that the Covid vaccine should be any different.
Antivaxxers use two examples when trying to scare you about long-term effects. Concerns about developing autism as a possible side effect is the most common, but this is so easy to debunk I'm not going to waste time; Google the evidence – it is rock solid.
Another one frequently mentioned on online forums is a link between narcolepsy and the 2009 swine flu vaccine. I work in the same hospital as the team which found this link, and there is good reason to believe this was a real connection. Yet even so, the risk was very small: it occurred in about one in 50,000 people given the injection. You need millions of people to be vaccinated to pick this kind of side-effect up. And the truth is that conventional, non-Covid-19 trial processes would not have done so (and in fact didn’t in this case). The other point was that this wasn’t even a long-term effect, as the majority of these rare diagnoses were made within months, not years. The mechanism of action was almost certainly quick with a delay in diagnosis, so this again highlights the lack of any evidence of long-terms problems.
So can I tell you that there won't be a long-term unknown side effect to the Covid jab? No. I can only tell you the chances of there being one are very, very, low. But what I do know is that, if the regulators license these vaccines, the risks to you from Covid-19 will definitely be higher. Watch the data yourself as it comes out. Take good counsel. If you are worried, keep an open mind and don't rush. You are unlikely to be offered a vaccine for months. We are a proud and usually sensible nation. No one is going to be forced to have a vaccine, but doing so is the wise choice.