Fig. 1

Experimental design timeline of immunizations and sequencing experiments. Six individuals naïve for 2009 pdmH1N1 were vaccinated with the 08/09 TIV and their peripheral blood IgG B cell repertoire was sequenced before vaccination (day 0) and 7 days after vaccination. Two years later, the IgG B cell repertoire of five to six individuals previously vaccinated plus eight additional participants vaccinated with 09 MIV (of 18 participants) were sequenced (day 0 and day 7). Finally, four of the same five participants vaccinated with 08/09 TIV and 09 MIV were vaccinated with 12/13 TIV. The same four participants were then vaccinated with 14/15 TIV and subjected to Rep-Seq (*), as in the previous trials. The overall experiment length from the first to the last vaccination trial was 5 years, 5 months