If I've had Covid-19, do I need a vaccine?

Why are the EU posturing around AstraZeneca's Covid-19 vaccine, and what will be the consequences? And if you've already caught coronavirus, should you still get vaccinated if you are already immune? What is ataxia and how can it be treated? Meanwhile, what causes rigor mortis and how long does it last? In Covid-19 genetic vaccines, how long does the foreign genetic material persist in the body and how does this compare to vaccines like the Johnson and Johnson agent? Plus why conspiracy theories and misinformation proliferated online are so toxic.