Natural immunity as protective as vaccine induced immunity https://www.cdc.gov/mmwr/volumes/71/w…
4 cohorts Unvaccinated:
- No previous diagnosis Vaccinated
- No previous diagnosis
- Unvaccinated with previous diagnosis
- Vaccinated with previous diagnosis
So, what happened to these people during delta?
By November 30, 2021, California and New York
Natural immunity without vaccination protected against delta admission
Subsequent vaccination boosts antibodies