1. ~30 million confirmed (worldometer) recovered from covid. Some official estimates put that number closer to 100 million. Those individuals already have covid immunity and do not need to take a vaccine. All vaccines carry some risk, even if low. There is no reason for someone who already has covid immunity to take on the risk of a vaccine.
Friend had Covid last year, wasn't too bad. Caught it again in Jan (before the chance to get vaccinated) and it hit her very hard. She's now suffering from a pretty miserable long Covid.
2. Guillain-Barre syndrome