About the Authors

Maria Valeri

Contributed equally to this work with: Maria Valeri, Vanessa Zurli

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Vanessa Zurli

Contributed equally to this work with: Maria Valeri, Vanessa Zurli

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Inmaculada Ayala

Affiliation Institute of Protein Biochemistry, National Research Council, Via P. Castellino 111, Naples, Italy

Antonino Colanzi

Affiliation Institute of Protein Biochemistry, National Research Council, Via P. Castellino 111, Naples, Italy

Lucia Lapazio

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Daniela Corda

Affiliation Institute of Protein Biochemistry, National Research Council, Via P. Castellino 111, Naples, Italy

Marco Soriani

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Mariagrazia Pizza

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Silvia Rossi Paccani

silvia.x.rossi-paccani@gsk.com

Affiliation Vaccines & Diagnostics s.r.l.—a GSK company- Via Fiorentina 1, Siena, Italy

Competing Interests

Co-authors Maria Valeri, Vanessa Zurli, Lucia Lapazio, Marco Soriani, Mariagrazia Pizza and Silvia Rossi Paccani are employed by Novartis Vaccines and Diagnostics S.r.l.- a GSK company. This work was supported by internal funding by Novartis Vaccines and Diagnostics S.r.l.- a GSK company. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: MV VZ IA AC DC MP SRP. Performed the experiments: MV VZ IA AC LL SRP. Analyzed the data: MV VZ AC IA MP DC MS SRP. Wrote the paper: MV VZ AC DC MP MS SRP.