To add it seems that it isn't quite as simple as "I had it so I'm immune". It does seem to vary significantly from person to person, one factor being the severity of the sickness. If it's not severe enough or if it's too severe then the immunity can be less. I don't think this area is understood enough to be confident in natural immunity alone.
Plus as mentioned natural immunity + vaccine seems to be more effective (twice as effective in a recent CDC study)
__________________
Uncertainty is an uncomfortable position.
But certainty is an absurd one.
|