April 19, 2024

New Type of Cholera Vaccine May Offer Much Longer-Lasting Protection

Referral: “Virus-like Particle Display of Vibrio cholerae O-specific Polysaccharide as a Potential Vaccine against Cholera” 16 February 2022, ACS Infectious Diseases.DOI: 10.1021/ acsinfecdis.1 c00585.
The authors acknowledge funding from the National Institutes of Health, the Fogarty International Center and Michigan State University. Xuefei Huang is the creator of Iaso Therapeutics Inc

A virus-like particle (Qβ-OSP conjugate) showing a polysaccharide from Vibrio cholerae germs generates a strong, long-lasting immune response in mice. Credit: Adapted from ACS Infectious Diseases 2022, DOI: 10.1021/ acsinfecdis.1 c00585.
Current vaccines last just 2– 5 years, and they do not work very well in young children.
Current cholera vaccines contain killed or weakened V. cholerae germs and are administered orally. They use the most affordable level and duration of protection in children, who are commonly impacted by cholera in endemic nations. The body immune system produces antibodies against the O-specific polysaccharide (OSP) on the surface of V. cholerae, however this polysaccharide in seclusion does not produce a strong, lasting immune reaction. Peng Xu, Edward Ryan, Xuefei Huang and associates questioned if connecting OSP to virus-like particles could cause more powerful, longer-lasting resistance.
So the scientists established a technique to efficiently link numerous copies of OSP to Qβ, a virus-like particle that contaminates bacteria. The customized virus-like particles were recognized by antibodies in blood taken from recovering cholera patients, but not from patients with typhoid, another bacterial illness. Next, the team immunized mice with Qβ-OSP, observing that three dosages triggered a strong antibody action that continued at least 265 days after the first dosage. The immunized mice had antibodies that recognized the OSP from the natural lipopolysaccharide of V. cholerae. When the researchers combined serum antibodies from the mice with other immune system proteins that eliminate bacteria and with live V. cholerae, antibodies from two of the 5 mice activated more bacterial death than those from mice vaccinated with Qβ alone. The virus-like particle could imitate natural bacteria by providing several copies of OSP on its surface area, the scientists state, and it calls for more examination as a next-generation cholera vaccine.

They provide the least expensive level and duration of protection in young children, who are commonly affected by cholera in endemic countries. The modified virus-like particles were recognized by antibodies in blood taken from recuperating cholera clients, but not from clients with typhoid, another bacterial disease. The virus-like particle might imitate natural germs by presenting several copies of OSP on its surface, the scientists state, and it warrants further evaluation as a next-generation cholera vaccine.