I was fortunate to receive my first COVID vaccine dose yesterday; I received the Astra Zeneca product and all seemed to go well. As seems to be common, it made me feel feverish overnight and I slept badly. This was reassuring in a way as it made me feel like it was ‘working’… it was exciting, in a strange sort of way, to imagine the billions of ‘virus fragments’ racing round my body infecting my cells and turning them into zombie spike protein factories!
However, my inability to sleep also made me realise that I had absolutely no idea how it really worked. So as I was struggling to sleep, I started reading more and more articles about these ‘viral vector’ vaccines. They really are quite fascinating. And these articles did answer my first wave of questions… but they also then triggered more questions, to which I couldn’t find any answers at all. I’m not sure I’m going to be particularly productive at work today so thought why not write down what I discovered and list out all my questions. Perhaps my readers know the answers?
Viral Vector Vaccines: Key Concepts
Most descriptions I found online were hopelessly confused or went into so much extraneous detail about various immune system cell types that they were useless in imparting any real intuition. However, what I did seem to discover, at a very high level, was something like the following:
A harmless virus is used as the starting point. Interesting detail: the virus needs to be somewhat obscure to reduce the risk patients’ bodies have been exposed to it before and thus already have antibodies that would destroy it before it’s had a chance to do its magic It is then genetically engineered so that when it invades a human cell it triggers the cell to start churning out chunks of protein (the famous spike protein) that look a bit like Covid-19 viruses. These spikes eventually become visible to the immune system, which mounts a vigorous response and, in so doing, learns to be on the lookout for the same thing in the future.
In essence, we infect ourselves with a harmless virus that causes our body’s own cells to start churning out little proteins that look similar enough to COVID that our body will be on high alert should a real COVID infection try to take hold.
Or, at least, I think that’s what’s going on.
So many extraneous details
Now, most of the articles I read then go on to talk about things like the following:
Technical detail about how several little fragments then have to be assembled to make one ‘spike’. Important but not really critical to understanding the concepts from what I can see The role of different types of immune cells. The only thing these kinds of articles taught me was that it’s clear that immunologists have no idea how the immune system works and their attempts at explaining it to lay readers just makes this painfully obvious