Development of Shigella conjugate vaccines targeting Shigella flexneri 2a and S. flexneri 3a using a simple platform-approach conjugation by squaric acid chemistry.

"Declaration of Competing Interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper."

"Financial Support: This research was supported through programs funded by the National Institutes of Health, including the National Institute of Allergy and Infectious Diseases (AI155414 and AI106878 [ETR, TRB, FQ]; AI177075 [ETR]), the Fogarty International Center, Training Grant in Vaccine Development and Public Health (TW005572 [RB, KI, MK]), and Emerging Global Fellowship Award TW010362 [TRB], and the Intramural Research Program of the NIH and NIDDK (PX and PK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."