A potentially longer-lasting cholera vaccine

Date:
February 16, 2022
Source:
American Chemical Society
Summary:
Researchers have developed a new type of cholera vaccine consisting
of polysaccharides displayed on virus-like particles. The vaccine
generated long-lasting antibody responses against V. cholerae
in mice.



FULL STORY ========================================================================== Cholera, a diarrheal disease caused by the highly transmissible
bacteria Vibrio cholerae, kills tens of thousands of people each year worldwide. Current vaccines last only 2-5 years, and they don't work
very well in young children.

Now, researchers reporting in ACS Infectious Diseases have developed
a new type of cholera vaccine consisting of polysaccharides displayed
on virus-like particles. The vaccine generated long-lasting antibody
responses against V.

cholerae in mice.


========================================================================== Current cholera vaccines contain killed or weakened V. cholerae bacteria
and are administered orally. They offer the lowest level and duration
of protection in young children, who are commonly affected by cholera
in endemic countries.

The immune system produces antibodies against the O-specific
polysaccharide (OSP) on the surface of V. cholerae, but this
polysaccharide in isolation does not generate a strong, long-lasting
immune response. Peng Xu, Edward Ryan, Xuefei Huang and colleagues
wondered if attaching OSP to virus-like particles could induce stronger, longer-lasting immunity.

So the researchers developed a method to efficiently link multiple
copies of OSP to Qb, a virus-like particle that infects bacteria. The
modified virus-like particles were recognized by antibodies in blood
taken from recovering cholera patients, but not from patients with
typhoid, another bacterial disease. Next, the team immunized mice
with Qb-OSP, observing that three doses caused a strong antibody
response that persisted at least 265 days after the first dose. The
immunized mice had antibodies that recognized the OSP from the natural lipopolysaccharide of V. cholerae. When the researchers mixed serum
antibodies from the mice with other immune system proteins that kill
bacteria and with live V. cholerae, antibodies from two of the five
mice triggered more bacterial death than those from mice immunized
with Qb alone. The virus-like particle could mimic natural bacteria by presenting multiple copies of OSP on its surface, the researchers say,
and it warrants further evaluation as a next- generation cholera vaccine.

The authors acknowledge funding from the National Institutes of Health,
the Fogarty International Center and Michigan State University. Xuefei
Huang is the founder of Iaso Therapeutics Inc.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Zahra Rashidijahanabad, Meagan Kelly, Mohammad Kamruzzaman, Firdausi
Qadri, Taufiqur R. Bhuiyan, Hunter McFall-Boegeman, Di Wu,
Grzegorz Piszczek, Peng Xu, Edward T. Ryan, Xuefei Huang. Virus-like
Particle Display of Vibrio cholerae O-Specific Polysaccharide as a
Potential Vaccine against Cholera. ACS Infectious Diseases, 2022;
DOI: 10.1021/ acsinfecdis.1c00585 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220216082957.htm

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