Thread by @nirav_mainecdc

1/Infection-induced (a/k/a 'natural') #COVID19 immunity and vaccine-induced immunity are again in the news.

This is a fascinating area of immunology, with numerous twists and turns.

cdc.gov/coronavirus/20…

2/It can be hard to digest the data and make sense of the various studies. Thankfully, the @CDCgov is out with a new Science Brief that does just that.

I recommend this Brief for anyone looking for an overview of the current scientific evidence.

cdc.gov/coronavirus/20…

3/Here are the key details from the review:

- Fully vaccinated individuals and those previously infected with SARS-CoV-2 each have a low risk of subsequent infection for at least 6 months.

4/ -- Data are presently insufficient to determine an antibody titer threshold that indicates when an individual is protected from infection.

- At this time, there is no FDA-authorized or approved test to reliably determine whether a person is protected from infection.

5/- Though there is a wide range in antibody titers in response to infection with SARS-CoV-2, completion of a primary vaccine series, especially with mRNA vaccines, typically leads to a more consistent and higher-titer initial antibody response.

6/- Substantial immunologic evidence and a growing body of epidemiologic evidence indicate that vaccination after infection significantly enhances protection and further reduces risk of reinfection, which lays the foundation for @CDCgov recommendations.