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Evaluation of a Burkholderia pseudomallei Outer Membrane Vesicle Vaccine in Nonhuman Primates
Hailey Petersen1, Wildaliz Nieves1, Kasi Russell-Lodrigue2
1Tulane University School of Medicine, New Orleans LA 70112, USA.
Abstract:
Burkholderia pseudomallei (Bps)is the causative agent of melioidosis and is endemic in regions of northern Australia and Southeast Asia. Bps is inherently resistant to multiple antibiotics and is considered a potential biological warfare agent by the U.S. DHHS. Therefore, effective vaccines are necessary to prevent natural infection and to safeguard against biological attack with this organism. In our previous work we have shown that immunization with naturally derived outer membrane vesicles (OMVs) from Bps provides significant protection against lethal aerosol and systemic infection in BALB/c mice. In this work, we evaluated the safety and immunogenicity of escalating doses of OMV vaccine in rhesus macaques. We show that immunization of rhesus macaques with Bps OMVs generates humoral immuneresponses to protective protein and polysaccharide antigens without any associated toxicity or reactogenicity. These results lay the groundwork for evaluation of protective efficacy of the OMV vaccine in the nonhuman primate model of melioidosis.
Insights
Outer membrane vesicles (OMVs) from Burkholderia pseudomallei (Bps) show promise as a vaccine. Studies in rhesus macaques indicate Bps OMVs are safe and generate immune responses, paving the way for efficacy trials.
Area of Science:
- Microbiology
- Vaccinology
- Immunology
Background:
- Burkholderia pseudomallei (Bps) causes melioidosis, a disease endemic in Southeast Asia and Northern Australia.
- Bps exhibits resistance to multiple antibiotics and is classified as a potential biological warfare agent.
- Effective vaccines are crucial for preventing melioidosis and mitigating biowarfare threats.
Purpose of the Study:
- To assess the safety and immunogenicity of escalating doses of Bps outer membrane vesicles (OMVs) vaccine in a nonhuman primate model.
- To determine if Bps OMVs can elicit protective immune responses without adverse effects.
Main Methods:
- Rhesus macaques were immunized with escalating doses of Bps OMVs.
- Humoral immune responses, including antibody production to key antigens, were analyzed.
- Safety and reactogenicity were monitored throughout the study.
Main Results:
- Immunization with Bps OMVs generated significant humoral immune responses in rhesus macaques.
- The immune responses targeted protective protein and polysaccharide antigens of Bps.
- No significant toxicity or reactogenicity was observed at any dose level.
Conclusions:
- Bps OMVs are safe and immunogenic in rhesus macaques.
- The vaccine candidate elicits humoral immunity against key Bps antigens.
- These findings support further investigation into the protective efficacy of the Bps OMV vaccine in a nonhuman primate model of melioidosis.
