Fig. 4
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12916-022-02547-2/MediaObjects/12916_2022_2547_Fig4_HTML.png)
Generalized additive models for associations of days since vaccination with antibody responses to the six isotype-antigen combinations in infected (red) and naïve (blue) participants after the a first and b second doses. Fitted lines after adjustment for participant’s age and type of vaccine. Plus symbols (+) represent measured responses for a specific participant. People vaccinated with the Janssen COVID-19 vaccine are not considered in this analysis