Wednesday, 17 February 2021

Covid#30 - We're all scientists now

 


Three days ago I had the first of my Covid vaccinations.  The next day was a total write-off as I suffered what I am assured was only a really strong immune response, which is a good thing, but didn’t feel that way with my head pounding and as waves of nausea enveloped me.  It only lasted twenty-four hours though, so I won’t dwell on that.

As the nurse removed the needle from my arm at the end of my brief appointment at a local pharmacy, I succumbed to that post-jab cliché of asking, ‘Is that it?!’  I actually meant it; it seemed so inconsequential.  It was, of course, nothing of the sort – not for me or for the now fifteen million people in the UK who have had the first of our two jabs.  When I returned to my car and posted on Facebook of my excitement and relief, it really did feel that something momentous had just happened.

Many months ago, I wrote about how ‘Covid19 will define our age as one of great scientific and technological discovery and endeavour’ (Covid#9).  Since then, we’ve all become scientists as we’ve understood the emergence of coronavirus and added zoonoses to our lexicon; grappled with how it spreads and how best to protect ourselves and each other; followed the race to develop treatments and vaccines; watched as the virus mutated and new variants took hold and now as we join hopefully in the mass-experiment that is this epic vaccination programme.  I, for one, have been fascinated by the science from the outset.

I am, in fact, in awe of coronavirus.  It’s effects are obviously dreadful, but it knows nothing about that.  It is simply doing what it’s meant to do – reproduce, thrive and survive – and what is literally awe-ful about it is just how well it does its job.  We’ve all become familiar with images of the virus, surrounded by its spike-proteins, designed to latch onto and unlock our own cells, but it’s both frightening and incredible that that spikey little ball is about one-hundredth the size of one of our cells and forever invisible to most of us who don’t own an electro-microscope.  Despite that, once it’s delivered its genetic material to our cells then instructed them to copy and reassemble it before self-destructing, it can have replicated itself billions of times in just a few days.

The mutations that resulted in the original zoonotic jump and the Kent, Brazil and South African variations of the virus that have caused so much concern since December may be more luck than judgement (from the virus’ perspective, that is) but it’s no less remarkable that by random chance, a copying error as it replicates can enable it to claim an unfortunate new host and enhance its effectiveness – or virulence.  How is it even possible that something so miniscule can contain enough material to mutate so significantly as to have such devastating consequences?  It’s wonderfully mind-boggling!

I’m equally impressed by our immune system.  A couple of years ago, I fell seriously ill.  As I lay in a hospital bed, wired up to machines with all sorts of tests being conducted, I was scared yet I had little cause to be because, as a doctor later explained to me, my incredible immune system had kicked in and was already doing a brilliant job of dealing with the infection in my liver.  For most people, the same is true of a coronavirus infection.  Despite having never experienced it before, somehow our body knows what to do and can fight it off before we suffer any more than mild symptoms.  Even when coronavirus infects our neutrophiles and t-cells, causing the overreaction known as a ‘cytokine storm’ and turning them against even healthy cells, in most of us, our immune system eventually wins out.  It fills me with wonder!

The scientists who discover and explain all this can not earn enough admiration and praise.  Thanks to them, I have learnt a lot about the basic science of the virus and our immune system, but it is beyond me how they managed to decode its genetic sequence in such short order after the outbreak began in China, use it to invent the tests that have become part of our everyday life and then track changes in that code over time, revealing those dastardly mutations.

That syringe bearing its crystal-clear vaccine seemed so insubstantial as it lay in its dull grey cardboard tray, awaiting my arm.  Truly however, it symbolised all that scientific endeavour about which I previously wrote.  I’ve watched Professor Teresa Lambe describe how the genetic code arrived in her e-mail inbox on a Saturday morning in January 2020 and how, clad in her pyjamas, she worked through the weekend to have a vaccine designed by the Monday.  By March, it had entered human trials.

I received the Oxford-Astrazeneca vaccine.  It’s a vector-vaccine that uses a modified version of a chimpanzee adenovirus, to which the gene for the coronavirus spike protein has been added.  Once my cells were ‘infected’ with this false-virus, the spike-protein was read by my cells’ nuclei and copied into messenger RNA; the adenovirus itself, however, had been engineered to not be replicated so I didn’t fall ill as a result.  The MRNA was then read by my cell’s molecules, which began assembling those spike-proteins.  Some of those spikes then protruded through my cells’ surface, awakening my immune system.  When the ‘infected’ cell died, the debris – including those spike-proteins – was swept up by antigen-presenting cells to be recognised by helper T cells.  B-lymphocytes activated by those helper T cells then poured out antibodies that latch onto genuine coronavirus spikes, marking them for destruction and preventing them from infecting other cells.  Meanwhile, killer T cells (which sound like something out of a science fiction film) were also activated by the antigen-presenting cells to find and destroy any of my cells infected by coronavirus. 

All this remarkable process was playing out at a microscopic level inside my body whilst I lay on the sofa nursing my headache, and it’s all thanks to the incredible efforts of the scientists at Oxford University and Astrazeneca and their friends all around the world.  I was shaking my head in disbelief and awe as I wrote even the second sentence of that last paragraph; it’s so easy to write a few words about adding a gene to a chimp virus, yet they undoubtedly represent so much research, understanding and effort.

That insubstantial-looking syringe, filled with its miraculous elixir and the hopes of everyone for an end to this pandemic, deserved to be made from lead-crystal and to rest on a velvet cushion atop a gold and jewel-encrusted tray!  I feel a bit sad that it was destined only for one of those vivid-yellow sharps bins.  A bit of me wishes I could have kept it.

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