How do antibodies against SARS-CoV-2 rise and decay after infection, when can they be detected? And when can RNA be detected in respiratory tract and other samples? These questions are the focus of our new meta-analysis: https://osf.io/evy4q/ 

Five months into the outbreak, many studies have measured antibodies and RNA in patients. But it is tricky to integrate the information, because of the variety in assays, protocols and reporting: in 23 studies, we find 8 antibody assays, 10 target antigens and 9 reporting units

We developed a way to combine different ways in which antibody and RNA results are reported. That means we can leverage existing data and get a good picture of what is really going on. When do antibodies appear? When do they peak? When can we find RNA in samples? Key results:

IgG and IgM antibodies appear around the same time (13 days after symptoms start), but this time varies a lot (ranging from 0 to >30 days). Different assays give similar results. And disease severity does not seem to affect seroconversion times either.

The probability of detecting IgG and IgM antibodies changes quickly, from around 10% at the start of symptoms, to 98-100% by day 22. IgG then remains present for at least 60 days (max. day in dataset), while some individuals start to lose IgM (60% positive by day 60).

SARS-CoV-2 RNA detection probability is high when symptoms start, and declines to 0 by day 30-40 (with possible exceptions;dataset up to day 50 only!). This is influenced by sample type! Lower respiratory and fecal samples are positive more often than upper resp.

Antibody increase rates, and time to peak level, are similar for IgG and IgM, and slightly affected by the choice of target antigen in the immunoassay. Peak levels are reached around 16 days after symptoms start. This is not different between mild and severe cases.

These results (and more), leveraging 3,214 data points from 516 individuals reported in 22 studies, can be found in our latest pre-print (any feedback welcome). https://osf.io/evy4q/ 

This was a fun inspiring team effort with @AmandineGamble, Katie Prager, Sarah Helman, @AbbyMcClain12 , Caitlin Cox, Van Savage, and @jlloydsmith.