Safety and immunogenicity testing of a melioidosis subunit vaccine candidate in cynomolgus macaques.

Authors

Sineenart Sengyee, Caitlyn E Orne, Sarah B Weiby, Lindsey K Schmidt, Federico Urbano-Munoz, Jiri Vlach, Christian Heiss, Parastoo Azadi, Narisara Chantratita, Mary N Burtnick, Paul J Brett

Published in

NPJ vaccines. Jul 14, 2026. Epub Jul 14, 2026.

Abstract

Burkholderia pseudomallei, the etiologic agent of melioidosis, is a Gram-negative bacterial pathogen that causes severe disease in humans and animals. In this study, we evaluated the safety and immunogenicity of our lead melioidosis subunit vaccine candidate in cynomolgus macaques. To accomplish this, the 6-deoxyheptan capsular polysaccharide (CPS) from Burkholderia thailandensis E555 was purified using a phenol-free extraction process and then conjugated to CRM197 to generate CPS-CRM197. Highly purified, His-tagless B. pseudomallei Hcp1 (Hcp1-TL) was also produced. Animals immunized with CPS-CRM197 combined with Hcp1-TL and adjuvanted with Alhydrogel plus CpG DNA (ODN 2006) developed robust CPS-specific IgG and opsonizing antibody responses, alongside strong Hcp1-specific IgG and measurable IFN-γ-secreting T-cell responses. Importantly, the vaccine formulations tested were well tolerated, with no adverse events after three doses. Collectively, these studies establish good manufacturing practices-compatible processes for our vaccine antigens and demonstrate the safety and immunogenicity of the subunit vaccine in non-human primates, supporting continued advancement towards a human clinical trial.

PMID:
42448712
Bibliographic data and abstract were imported from PubMed on 15 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.