The world is being held hostage by an organism so small that even the most powerful microscope could miss it. It has taken thousands of lives and brought superpowers to their knees. It has also united us in suffering and opened our eyes to the fragility of our way of life. A proposed panacea is vaccination. But will a vaccine be found? Or is the search for one likely to prove fruitless? In order to appreciate the magnitude of such a task, it is important to understand a little of the biology, history and challenges of vaccine development. Here there emerge three good reasons why a vaccine might not be possible. Or, at best, is likely to be a long way off.
Sars-CoV-2 (the virus that gives rise to Covid-19) has an outer membrane which protects the genetic material (RNA) inside.