3 ms·
No one knows when vaccine or natural immunity expires. We only know that it doesn't expire within 6 months, because that's the longest it has been tested so far
by spfzero 6y ago
No one knows when vaccine or natural immunity expires. We only know that it doesn't expire within 6 months, because that's the longest it has been tested so far. Most experts expect immunity to last much, much longer than that.
- nikolay 6y agoActually, it does as titres of antibodies drop in time.